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470 Cards in this Set
- Front
- Back
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What is the apex of the orbit
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Optic foramen
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What is the base of the orbit
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the orbital rim
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What are the contents of the orbit
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Eyeball
Lacrimal apparatus Muscle Nerves vessels orbital fat |
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What bones make up the orbit of the eye
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Frontal
Maxilla zygomatic sphenoid ethmoid lacrimal palatine |
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Roof of bony orbit
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Related to ant. cranial fossa
Orbital part of frontal Lesser wing of sphenoid |
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Medial wall of orbit
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Paper thin
Related to ethmoidal and sphenoidal sinuses Ethmoid Frontal Lacrimal Sphenoid |
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Lateral wall of orbit
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Thickest
Frontal process of zygomatic bone Greater wing of sphenoid |
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Floor of orbit
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Separated from lateral wall by inf. orbital fissure
Related to maxillary sinus Maxilla Zygomatic Palatine Most commonly affected by blow out fractures |
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Blow out fracture
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Blunt trauma to head displaces medial/inferior walls
Pushes intraorbital contents to sinuses Pain Paresthesia Swelling Diploplia Upward gaze inhibited Enophthalmos |
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Features of bony orbit
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Optic canal
Superior orbital fissure Inferior orbital fissure Supraorbital notch (foramen) Infraorbital groove and canal Nasolacrimal gland Ant. ethmoidal foramen Post. ethmoidal foramen Zygomaticoorbital foramen Lacrimal fossa Lacrimal groove |
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Optic canal
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Communicates with middle cranial fossa
Optic nerve Opthalmic artery |
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Superior orbital fissure
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Communicates with middle cranial fossa
Superior ophthalmic v V1 branches CN III, IV, V1 |
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Inferior orbital fissure
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Communicates with pterygopalatine fossa
Orbiital and zygomatic br of V2 Inferior ophthalmic v vv comm. w/ pterygoid plexus |
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Supraorbital notch (foramen)
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Supraorbital a and n
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Infraorbital groove and canal
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Infraorbital a and n
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Nasolacrimal canal
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communicates with inf. nasal meatus
passage of tears to nose Nasolacrimal duct |
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Ant. ethmoid foramen
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Ant ethmoid a and n
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Post ehtmoid foramen
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Post ethmoid a and n
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What separates eyelids
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Separated laterally by medial and lateral palpebral commisures (at angles of eyes)
form palpebral fissure when eyes open |
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Cutaneous portion of eyelids
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skin containing appendages and orbicularis oculi (palpebral) and dense CT (tarsal plate)
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Conjunctival portion of eyelids
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Palpebral conjunctiva inside
Separated from bulbar conjunctiva (over eyeball) at limbus by sup and inf conjunctival fornices |
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Skin appendages of eyelids
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Sweat and sebaceous glands:
Eyelashes associated with sebaceous glands (glands of Zeiss) Modified sweat glands (glands of Moll) |
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Tarsal plate
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Dense CT
Responsible for rigidity of eyelids Insertion of levator palpebrae superioris (voluntary) and superior tarsal muscle (involuntary) Contains large sebaceous glands (tarsal or Meibomean glands) |
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Tarsal glands
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Secrete lipid part of tearfilm
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Hordeolum
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Sty
Acute focal infection of eyelid Affects Meibomian glands (internal) or glands of Zeiss (External) due to obsruction or infection of eyelash |
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Chalazion
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Noninfectious obstruction of meibomian glands causing extravasation of lipid material in eyelid soft tissues with focal secondary granulomatous inflammation
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Bell's palsy
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Inability to fully close eyelids
Caused by paralysis of orbicularis oculi muscle usually due to damage of CN VII |
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Ptosis
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Drooping of eyelid
Caused by paralysis of: Levator palpebrae superioris (oculomotor paralysis) Superior tarsal muscle (Muller's muscle) such as damage to sympathetic nerves (Horner syndrome) |
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What composes the lacrimal apparatus
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Lacrimal glands
Lacrimal duct Lacrimal lake Lacrimal caruncle Semilunar conjunctival fold Lacrimal punctum Lacrimal canaliculi Lacrimal sac Nasolacrimal duct Inf. meatus |
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Lacrimal glands
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In lacrimal fossa
Produce tears |
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Lacrimal duct
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Flow of tears is from superior lateral inferior medial
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Where is the lacrimal punctum
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On lacrimal papillae
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What is the lacrimal sac
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Dilated part of nasolacrimal duct
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Nerve supply to lacrimal gland
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VII - greater petrosal n
V branch: Maxillary (V2) Zygomatic n, lacrimal n (V1) Supplies lacrimal gland |
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What supplies the lacrimal apparatus
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Parasymp - secretomotor
Symp - vasoconstriction |
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Layers of walls of eyeball
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Fibrous layer
Vascular layer (uvea) Neural layer |
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What is in the fibrous layer of eyeball
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Sclera
Cornea Corneoscleral junction (limbus) |
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What is in the vascular layer of eyeball
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Choroid
Ciliary body Iris (pupil is its central aperture) |
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What is in the neural layer of eyeball
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Retina
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What composes the eyeball
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Coats (walls)
Lens Vitreous body |
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What makes up the ciliary body
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Ciliary mm and processes
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Ciliary processes - what do they do? What do they connect to and how?
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Secrete aqueous humor
Connected to lens by suspensory lig |
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Ciliary body mm
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Ciliary m (III)
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What mm does the iris have
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Sphincter pupillae (parasymp, III)
Dilator pupillae (symp) Control light through pupil |
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What does the sphincter pupillae do
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Causes pupilloconstriction (miosis or myosis)
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What does the dilator pupillae do
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Pupillodilation (mydriasis)
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What do the ciliary mm do when they are relaxes
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Pull on and flatten lens
Allow eye to see objects that are far |
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What do ciliary mm do when they contract
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Relax suspensory lig and thicken lens (accomodation)
To see things that are close |
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Aqueous humor - what secretes it
where is it secreted what is its path what does it drain into |
Secreted by ciliary processes into posterior chamber which flows around the iris and through the pupil into the anterior chamber
Drains to the trabecular meshwork in the iridocorneal junction to exit through spaces of Fontana and into the Schlemm's canal then the scleral venous system |
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Retinal layers
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10 of them
Outer pigmented layer Inner neural with: Rods Cones Bipolar cells Ganglion cells Optic disc |
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Optic disc
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Where optic nerve is formed by axons of ganglion cells
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What is the outermost layer adjacent to choroid of the retina
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Adjacent to choroid
Retinal pigment epithelium |
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What is the outermost layer of retina
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Nerve fiber layer that form optic n in optic disc
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Where are rods and cones
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Outer nuclear layer
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What are rods and cones for
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Rods are for night vision
Cones for color vision |
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Where is the highest concentration of cones
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Fovea (most acute vision)
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What is the fovea
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Small pit in macular lutea lateral to optic disc
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Blood supply to retina
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Through central retinal artery whose brs divide in optic disc
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Macular degeneration
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Photoreceptor degeneration, mainly cones, in fovea
Loss of central vision Initial damage to RPE from various factors including oxidative stress lead to loss of support to photoreceptors (dry type AMD) Complications: retinal neovascularization which can block vision, retinal detachment Can use: anti-angiogenesis therapy for wet type AMD, anti-oxidants and vitamins for dry type |
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Primary open angle glaucoma
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Decreased excretion of aqueous humor in trabecular meshwork
Increased pressure in anterior chamber Increased intraocular pressure (not always) Optic nerve damage (optic neuropathy) - cupping during fundoscopy degeneration of ganglion cells loss of peripheral vision |
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Extraocular mm
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Superior rectus
Inferior rectus Lateral rectus Medial rectus Superior oblique Inferior oblique Levator palpebrae superioris |
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What ocular mm take origin from common tendinous ring
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Superior rectus
Inferior rectus Lateral rectus Medial rectus |
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EOM origins and insertions
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All of the rectus mm have an origin on a common tendinous ring
Superior oblique, inferior oblique, and levator palpebrae superioris originate elsewhere All insert onto the eyeball except LPS which inserts on eyelid |
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EOM ocular movements
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?
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Abduction of EOM
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Lateral rectus
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Adduction of EOM
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Medial rectus
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Elevation of EOM
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Inferior rectus
Superior rectus |
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Depression of EOM
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Superior oblique
Inferior rectus |
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Multiple actions of EOM
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Primary
secondary Tertiary actions Axis of orbit is not same as axis of eyeball |
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How to test an individual muscle
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Isolate it and then bring its long axis into alignment with the axis of the eyeball
Some of motions used to test EOMs will not match normal action |
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Arterial supply to eyeball - branches of ophthalmic a.
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Lacrimal a
Central retinal a Long and short posterior ciliary aa Muscular aa Supra-orbital a Posterior ethmoidal a Anterior ethmoidal a medial palpebral a Dorsal nasal a Supratrochlear a |
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Venous drainage of eyes?
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Superior ophthalmic v
Inferior opthalmic v Infraorbital v |
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CN VI -abducens
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Passes through the cavernous sinus (involved in cavernous sinus thrombosis)
Enters orbit through superior orbital fissure Passes through common tendinous ring Supplies (GSE) the lateral rectus muscle (abduction) |
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CN IV -trochlear
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Passes through cavernous sinus
Enters orbit through superior orbital fissure Courses outside the common tendinous ring Supplies (GSE) the superior oblique m |
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CN III - oculomotor n
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Passes through superior orbital fissure (typically already divided into superior and inferior divisions)
passes through common tendinous ring where the extrinsic oculomotor muscles attach |
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Divisions of CN III
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Superior division - GSE:
Levator palpebrae superioris m Superior rectus m Inferior division (GSE, GVE): Medial rectus m Inferior rectus m Inferior oblique m Pregan parasym fibers to ciliary ganglion |
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parasympathetic supply of intrinsic eye muscles
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III
Ciliary ganglion V branch - Ophthlamic Preganglionic fibers synapse in ciliary ganglion Postgang fibers from ciliary ganglion to the eye via short ciliary nn innervate the sphincter pupillae and ciliary muscle |
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Sympathetics for eyeballs
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Postganglionic symp:
From superior cervical ganglion Travel on internal carotid a and brs Enter eyeball via superior orbital fissure along branches of V1 and reach eyeball via short and/or long ciliary nn Innervate dilator pupillae m |
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Ophthalmic n V1
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Branches: NFL
Inside common tendinous ring - nasociliary Outside common tendinous ring - frontal br and lacrimal br |
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V1 Lacrimal n
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No brs
Receives postganglionic parasymp fibers GVE from pterygopalatine ganglion via br of zygomatic n Sensory of lacrimal gland, conjunctiva, lateral part of upper eyelid (GSA) |
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V1 Frontal Nerve
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Largest branch
Divides into: Supratrochlear n Supraorbital n Sensory to conjunctiva, upper eyelid, parts of forehead and scalp (GSA) |
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Where does the supratrochlear n exit
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Supratrochlear foramen (medial)
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Where does the supraorbital n exit
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Supraorbital foramen (notch)
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V1 Nasociliary n
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Sensory (GSA) only branches:
Infratrochlear n Ant. ethmoidal n. posterior ethmoidal n. Long ciliary nn (fibers to iris/cornea) Branches carrying autonomic fibers (GVE): Long ciliary nerves Short ciliary nerves |
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Long ciliary nerves
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Carry sympathetic fibers to dilator pupillae
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Short ciliary nn
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Branches of ciliary ganglion, carry sympathetic, parasympathetic and GSA
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Horner's syndrome
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Interruption of the sympathetic pathway of eye
Ptosis: denervation of muller muscle Miosis: pupillary constriction; denervation of dilator pupillae Anhidrosis Enophthalmos - sunken eyeball; due to paralysis of orbitalis m |
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What does the orbitalis muscle do
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Smooth m
On floor of inf. orbital fissure - helps maintain the forward position of orbital structures |
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Pathophysiology of Horner's syndrome
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?
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Causes of horner' syndrome
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?
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Corneal reflex
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Evaluates the ophthalmic division of CN V (afferent limb) and
CN VII motor innervation of orbicularis oculi (effferent) Both eyes should close equally and consensually |
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Clinical correlation of corneal reflex
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?
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Pupillary light reflex
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Light stimulates retinal photoreceptors
Optic n synapse in pretectal nucleus, B/L innervation of Edinger-Westphal nucleus, oculomotor n, ciliary ganglion, short ciliary nerves, sphincter pupillae m, pupilloconstriction |
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Edinger Westphal nucleus
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?
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What does CN II do
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Optic nerve - responsible for vision
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What components does CN II have
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SSA
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What are the optic nerve and neural retina derived from
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Optic vesicle - an evagination of the developing forebrain
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Path of optic nerve
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Begins at optic chiasm (located above the pituitary gland and the surrounding sella turcica and between the cerebral part of the internal carotid aa)
travels anterolaterally to enter the optic canal along with the ophthalmic artery |
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Where does the optic nerve enter the orbit
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Enters at its apex, passing through the common tendinous ring and traveling anteriorly and downward through intraconal fat to back of eyeball where it pierces the sclera to become the optic nerve head
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Central artery of retina
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Pierces the optic nerve shortly before entering the globe
Divides into the superior and inferior branches at the optic disc |
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What are observed during a funduscopic exam
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Central artery of retina
Optic disc |
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What surrounds the optic nerve
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Extensions of the meninges including the subarachnoid space
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Papilledema
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Swelling of optic disc
Due to increases in CSF pressure that slow venous return and interfere neuronal axoplasmic transport Manifests as blurring of disc margins, mushrooming in advanced stages, disc hyperemia, and loss of venous pulsations |
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Where do the neuronal processes that form the optic nerve originate
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In the retina (ganglion cells)
AXons that form the inner most layer of the retina and coalesce at the optic disc |
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Blind spot
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optic disc
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What happens to ganglion cell axons that originate from the nasal retina
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They decussate at the optic chiasm to enter the contralateral optic tract
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What happens to ganglion cell axons that originate from the temporal retina
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Travel in ipsilateral optic tract
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What happens if retina or optic nerve is disturbded
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Visual defects on same side
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What happens if chiasmic or retrochiasmic lesion
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Can affect vision on both sides
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Which nerves contain GSE fibers that innervate extraocular (extrinsic) muscles
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CN III, IV, VI
Movement of eyeball within the orbit |
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Extraocular muscles
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Superior oblique
Lateral rectus Superior rectus Inferior oblique Inferior rectus Medial rectus |
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What innervates the superior oblique
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Trochlear n (IV)
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What innervates the lateral rectus
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Abducens n (VI)
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What innervates the superior rectus
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Oculomotor n (III)
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What innervates the inferior oblique m
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slide 7
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What innervates the inferior rectus
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slide 7
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What innervates the medial rectus
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slide 7
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What does the oculomotor n carry
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Fibers important for control of the sphincter pupillae and ciliary muscle
Innervates levator palpebrae superioris and other extraocular mm (SR, IO, IR, MR) GSE and GVE: somatic motor and pregang parasymp |
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Proprioceptive input from extraocular mm
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Enters CNS with V1
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Path of CN III
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Exits ventral aspect of midbrain
Travels forward splitting to form a superior and inferior division before exiting the cranium via superior orbital fissure 2 divisions emerge from the inferior portion of the SOF within the common tendinous ring |
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Superior division of CN III - path
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Travels above the optic nreve to innervate superior rectus m and levator palpebrae superioris
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Inferior division of CN III - path
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SPlits into medial, central, and lateral branches
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Lateral branch of inferior division of CN III
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Innervates the inferior oblique
terminal branch Sends communicating branch to ciliary ganglion ultimately supplying parasympathetic innervation to the sphincter pupillae and ciliary mm |
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Central branch of inferior division of CN III
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Descends to innervate the inferior rectus
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Medial branch of inferior division of CN III
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Crosses underneath the optic n to innervate the medial rectus
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Ciliary ganglion
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Associated with nasociliary br of CN V1
preganglionic parasymp fibers (GVE) that initially travel in CN III form the motor root of the ciliary ganglion and thereby enter the ganglion to synapse Postgang parasym fibers enter the eyeball via short ciliary nn (V1) to innervate the intrinsic eye mm |
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Short ciliary nn
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carry postgan parasymp fibers to eyelid for intrinsic eye mm
also carry postgan symp fibers from internal carotid plexus and GSA fibers that don't synapse |
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Ganglion of CN III
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Ciliary ganglion
CN V branch - ophthalmic Target - intrinsic eye mm |
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CN IV
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trochlear nerve
innervates the superior oblique GSE - somatic motor Exits the dorsal aspect of the brainstem at the junction between midbrain and pons Wraps around brainstem and travels anteriorly to exit the cranium via the superior orbital fissure |
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Where does CN IV emerge from the SOF
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Above the common tendinous ring
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How does CN IV travel - where in orbit
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Nerve travels along superior medial wall of the orbit to innervate the superior oblique muscle
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CN VI - what does it innervate
what are its components where does it exit brainstem |
Abducens nerve innervates lateral rectus muscle
GSE Exits ventromedial aspect of the brainstem at the junction between the pons and the medulla oblongata |
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How does the abducens nerve enter the orbit
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Via superior orbital fissure, passing through the common tendinous ring
Travels forward to innervate the lateral rectus |
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What does CN V provide
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Sensory innervation (GSA) for the face, eyes, nasal and oral cavities and the dura of the anterior and middle cranial fossae
Motor innervation for the mm of mastication (SVE) |
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How does CN V emerge
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from ventral lateral pons (middle brainstem) as 2 roots: a small more ventrally located motor root and a larger sensory root
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Stuff in green on slidew 17
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?
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Where are most of the sensory neurons of CN V
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within the trigeminal (semilunar or gasserian) ganglion
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Where does the trigeminal ganglion sit
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WIthin a fold of dura mater - Meckel's cave, on the trigeminal impression, a small concavity on the petrous temporal bone located behind its apex
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Where are the cell bodies of the trigeminal afferent neurons carrying proprioception
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Within CNS
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what does the trigeminal ganglion give rise to
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Ophthalmic (CN V1) sensory division
Maxillary (CN V2) sensory Mandibular (CN V3) sensory and motor |
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Where is the motor root of CN V
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Passes below the trigeminal ganglion (within Meckel;s cave) and merges with the mandibular nerve as it traverses the foramen ovale
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How do postganglionic parasympathetic fibers reach their targets
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Via CN V
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Divisions of opthalmic nerve
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Divides before exiting the middle cranial fossa via the SOF
Divides into: Frontal n Nasociliary n Lacrimal n |
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Tentorial n
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Br of recurrent meningeal
given off of V1 in middle cranial fossa Supplies tentorium cerebelli and posterior part of falx cerebri |
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Frontal n
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Largest br of V1
travels outside common tendinous ring passes forward over superior surface of levator palpebrae superioris Splits into 2 branches about halfway through the orbit |
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Branches of frontal n
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Supraorbital n:
Exits through the supraorbital notch or foramen and travels up to forehead to innervate the frontal sinus, mid upper eyelid, anterolateral forehead, and scalpo to interauricular line Supratrochlear n: Passes by the lateral aspect of the trochlea to exit through the frontal notch and innervate the medial superior eyelid and anteromedial forehead |
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Nasociliary n
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Enters orbit through common tendinous ring, crosses over optic n and travels obliquely under SR muscle
Slips between SO and MR mm and continues anteriorly along medial wal of orbit to the internal angle of the eye iNnervates tthe: Eyeball Mucosa of ethmoid and sphenoid sinuses and nasal cavity Skin of external nose and upper eyelid |
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branches of nasociliary n
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Communicating br to ciliary ganglion
long ciliary nn posterioor ethmoidal n |
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Communicating br of ciliary ganglion
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GSA fibers from eye travel through short ciliary nerve to ciliary ganglion - pass through without synapsing and enter nasociliary n
contains postgan symp fibers traveling in nasociliary n from ophthalmic a plexus in absence of independent symp root to ciliary ganglion |
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Long ciliary nn
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Contains GSA fibers from eye and carries postgan symp to dilator pupillae
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Posterior ethmoidal n
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Travels through the posterior ethmoidal foramen in the medial wall of the orbit
Supplies the mucosa of the posterior ethmoidal and sphenoid sinuses |
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3 roots of ciliary ganglion
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slide 25
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terminal branches of nasociliary n
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anterior ethmoidal n
infratrochlear n |
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Anterior ethmoidal n
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Travels thoruhg ant ethmoidal foramen in medial wall of orbit
enters ant cranial fossa, travels forward along side the crista galli, giving off anterior meningeal br drops down into nasal cavity through slit in cribiform plate of ethmoid bone and gives off medial and lateral internal nasal nn, exits the nose b/w the inf border of the nasal bone and lateral nasal cartilage to terminate as the external nasal n innervates ant and middle ethmoidal air cells, dura of ant cranial fossa including anterior falx, mucosa of anterosuperior part of nasal cavity and skin of nasal ala and dorsum of nose |
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Infratrochlear n
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COntinues along medial wall of orbit, exits orbit below trochlea of oblique m
innervates meedial portion of eyelids, skin of side of nose, and lacrimal sac and caruncle |
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Lacrimal n
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Enters orbit outside of common tendinous ring
travels forward along lateral wall of orbiit, passes through lacrimal gland and orbital septum and temrinates in lateral upper eyelid innervates: lacrimal gland, skin and mucosa of lateral upper eyelid |
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Lacrimal gland
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Receives postgang parasymp fibers that originate in the pterygopalatine ganglion through communicating br from zygomaticotemporal n
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When do CNs travel through cavernous sinus and which ones do
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CN III, IV, VI, V1 travel through cavernous sinus immediately before entering orbit
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What is the cavernous sinus
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Venous plexous that lies on either side of sella turcica extending from superior orbital fissure to the apex of the petrous temporal bone
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Internal carotid artery cavernous part
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Passes forward through the lumen of the sinus along with CN VI and its associated symp plexus
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Wher ein the cavernous sinus are CNs
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CNs III, IV, V1, V2 are in lateral wall
VI |
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CN VIII
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vestibulocochlear n
SSA 2 divisions: cochlear n vestibular n |
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Cochlear n
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Carries information from cochlea for audition
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Vestibular n
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carries info from vestibular apparatus for position and movement of the head in space
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Path of vestibulocochlear n
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Originates at the junction of the medulla, pons, and cerebellum (cerebellopontine angle)
travels through the posterior cranial fossa to enter the petrous temporal bone via the internal acoustic meatus divides into cochlear and vestibular divisions in the canal |
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Path of cochlear n
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Exits the distal end of the internal acoustic meatus and travels to nearby base of cochlea
Fascicles of the cochlear n enter the modiolus via apertures within its base neurons ascend within modiolus to base of spiral lamina |
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Spiral ganglia
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Within the bony modiulus
contain cell bodies of bipolar cochlear neurons |
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Where do the distal processes of the cochlear neurons go
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Travel to organ of corti where they synapse with hair cells
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Vestibular (Scarpa) ganglion
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Contains cell bodies of bipolar vestibular neurons
Is found within the distal end of the internal acoustic meatus |
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Divisions of vestibular n
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distal to ganglion
superior and inferior division and each one gives off distinct brs that innervate different parts of the vestibular apparatus |
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Where do CN IX and X exit the brainstem
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glossopharyngeal and vagus nerves exit the anterolateral aspect of the medulla oblongata
both travel laterally through the posterior cranial fossa to exit the cranium via the jugular foramen along with CN XI |
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Components of CN IX
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GSA
GVA/SVA SVE GVE |
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GSA of CN IX
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sensations from external ear - travels in auricular n
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GVA/SVA of CN IX
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visceral afferents from carotid body and carotid sinus
posterior 1/3 of tongue, pharynx, pharyngotympanic tube, and tympanic cavity special sensory to posterior 1/3 of tongue for taste |
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SVE of CN IX
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motor to stylopharyngeus
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GVE of CN IX
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parasymp to otic ganglion (parotid gland)
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Sensory ganglia of CN IX
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superior and inferior (petrosal) ganglia of the glossopharyngeal n are formed as the nerve exits the jugular foramen
inferior ganglion has cell bodies of GVA and SVA afferents, while the GSA neurons are found in ther superior ganglion |
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course of CN IX
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descend anterior to internal carotid artery, winds around lateral aspect of stylopharyngeus, travels forward medial to hypoglossus and finally passes b/w superior and middle constrictor mm to reach posterior tongue and pharynx
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Branches of CN IX
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tympanic n (lesser petrosal)
carotid sinus n pharyngeal brs n to stylopharyngeus toonsilar brs lingual brs |
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what does the tympanic n supply
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parasymp to otic ganglion (parotid gland)
sensory to tympanic cavity |
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Path of tympanic n
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branches off at or below inferior ganglion
enters middle ear via the tympanic canaliculus to form tympanic plexus gve fibers enter the lesser petrosal n which enters cranium through the roof of the tympanic cavity via the hiatus of the lesser petrosla n exits the cranium via the foramen ovale and fibers synapse in the otic ganglion postganglionic fibers exit the otic ganglion and join the auriculotemporal n to innervate the parotid gland sensory fibers are also distributed from tympanic plexus providing innervation for middle ear, pharyngotympanic tube and mastoid air cells |
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Ganglion of CN IX
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otic
via mandibular br to parotid gland |
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carotid sinus n
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monitor arterial blood pressure and blood O2 and CO2 levels
descends in front of internal carotid a to innervate GVA to the carotid sinus and carotid body |
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carotid sinus and body
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sinus for baroreceptors
body for chemoreceptos |
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pharyngeal brs
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from CN IX
sensory to mucosa of pharynx several brs given off to join the pharyngeal brs of vagus n and cervical symp trunk in forming the pharyngeal plexus on the posterior aspect of the middle constrictor m |
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N to stylopharyngeus
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From CN IX
motor innervation (SVE) to the stylopharygneus m |
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tonsillar brs of CN IX
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Sensory (GVA) to palatine tonsil and tonsillar pillars
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lingual brs of CN IX
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GVA from post 1/3 of tongue
taste afferents (SVA) from posterior 1/3 of tongue and vallate papillae |
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Components of vagus n
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GSA
GVA/SVA SVE GVE |
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GSA from CN X
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sensation from external auditory meatus and dura mater of post cranial fossa
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GVA from CN X
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visceral afferents from pharynx and larynx and from viscera of thoracic and abdominal cavity to the L colic flexure
also br to carotid body |
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SVA for CN X
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taste afferents from epiglottis and extreme root of tongue
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SVE for CN X
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motor to mm of palate (except tensor veli palatini)
pharynx mm (except stylopharyngeus) mm of larynx upper 2/3 of esophagus |
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GVE for CN X
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parasymp to heart, lungs, and digestive tract to L colic flexure
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Where does CN X exit
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Exits the posterior fossa via the jugular foramen
continues inferiorly within the carotid sheath behind and between the carotid artery and internal jugular vein |
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Sensory ganglia of CN X
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at and below jugular foramen
superior jugular ganglion inferior nodose ganglion |
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Superior jugular ganglion
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contains general somatic afferents most of which enter the auricular n
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INferior nodose ganglion
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contains visceral afferents and some taste (SVA) afferents
AKA inferior ganglion of vagus n |
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Where does the cranial accessory n merge with the vagus
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Immediately above the inferior ganglion
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Branches of CN X within the head and neck region
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Meningeal br
Auricular br pharyngeal br (n to carotid body) superior laryngeal n cervical cardiac brs recurrent laryngeal n |
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Meningeal br of CN X
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arises from superior vagal ganglion and reenters the cranium via the jugular foramen to innervate (GSA) the dura mater of the posterior cranial fossa
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Auricular br of CN X
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arises from the superior vagal ganglion and receives a communicating br from inferior ganglion of CN IX
nerve enters the mastoid canaliculus, traverses the temporal bone, emerging through the tympanomastoid fissure to innervate (GSA) the external ear and tympanic membrane |
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Pharyngeal brs of CN X
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provides motor innervation SVE to mm of soft palate (except tensor veli palatini) and the pharynx (except stylophar)
arises from the rostral part of the inferior vagal ganglion, travels between external and internal carotid aa to contribute to pharyngeal plexus |
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N to carotid body
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Innervates (GVA) the carotid body
Originates from pharyngeal br of vagus |
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superior laryngeal n - what does it carry
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GVA and taste (SVA) from extreme root of tongue and epiglottis
visceral sensory from larynx motor to inferior pharyngeal constrictor and cricothyroid m |
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what does the superior laryngeal n arise from
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caudal part of inferior vagal ganglion
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Divisions of superior larnygeal n
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internal br and external br
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Internal br of superior laryngeal n
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Pierces thyrohyoid membrane and provides sensroy innervation to the root of the tongue, epiglottis, and larynx above the vocal folds
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External br of superior laryngeal n
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Travels downward medial and posterior to superior thyroid artery and v to innervate the cricothyroid m and inferior constrictor
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Cervical cardiac brs
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Pregan parasymp fibers (GVE) to cardiac plexuses
usually 2 brs given off as vagus descends to root of neck |
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Recurrent laryngeal n
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Sensory (GVA) to larynx below the vocal folds
motor innervation (SVE) to all intrinsice mm of larynx (except cricothyroid) Travel upward adjacent to trachea and pass deep to inferior constrictor to innervate larynx |
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R recurrent laryngeal
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Wraps under and behind 1st segment of subclavian artery
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L recurrent laryngeal
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Loops under and behind the aortic arch and ligamentum arteriosum
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CN XI
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2 parts: cranial root and spinal root
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Cranial root CN XI
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acually part of vagus n
travels short distance with spinal roota and joins vagus n superior to the inferior vagal ganglion SVE fibers from it travel most of their course with vagus, contributing to its pharyngeal and recurrent laryngeal brs |
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spinal root of CN XI - where des it originate, where to its rootlets go
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motor nerve
originate in spinal accessory nucleus located in lateral portion of ventral horn found from spinal cord medullary junction down to C5ish rootlets exit the lateral aspect of the spinal cord to form a trunk that ascends posterior to the denticulate ligs and enters the cranium through the foramen magnum |
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Where does the spinal accessory n exit and what does it descend with
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Exits the cranium via jugular foramen and descneds with the internal jugular v to innervate (GSE) the SCM and continue inferiorly to innervate the trap
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CN XII - what does it supply
where does it emerge from brainstem where does it exit cranium |
hypoglossal n
provides GSE motor innervation to all mm of tongue except for palatoglossus emerges between pyramid and olivary eminence of medulla oblongata exits cranium via hypoglossal canal meningeal br recurs through hypoglossal canal to innervate the dura of the posterior cranial fossa terminal br innervates the styloglossus, hyoglossus, genioglossus, and intrinsic tongue mm |
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Auricle
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AKA pinna
consists of: skin cartilage (elastic) intrinsic and extrinsic mm (CN VII) Blood supply: Posterior auricular from ext carotid Anterior auricular from superficial temporal |
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Features of the auricle
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Slide 4
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Sensory innervation of auricle
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Cervical plexus:
lesser occipital n greater occipital n CN: V3 facial n vagus n glosspharyngeal n |
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Perichondral hematoma or hematoma auris
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AKA cauliflower ear
common injury in: wrestling rugby boxing causes discomfort and trouble hearing |
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External acoustic meatus - where is it, what does it contain and what is its innervation
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Extends from concha to tympanic membrane
Contains hair and modified sweat glands that produce cerumen (ear wax) main sensory innervation from V3 (IX) and X |
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tympanic membrane
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handle of malleus - attachment at umbo
cone of light anterior and posterior malleolar folds - pars flaccida and pars tensa sensory innervation - V, VII, and X for outer surface; IX for inner |
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Tympanostomy/myringotomy
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Tube or grommet is placed in tympanic membrane and is used to manage otitis media with effusion
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Perforated tympanic membrane
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Burst eardrum
Often due to sports Opens middle ear to external ear high risk of infection |
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Middle ear - what bone is it in
what does it contain what is it adjacent to |
Located in temporal bbone
contains ossicle Adjacent to: facial n in facial canal jugular bulb in jug foramen int carotid a in carotid canal |
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What are the 2 parts of the middle ear
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Tympanic cavity
Epitympanic recess |
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How does the middle ear communicate with the nasopharynx
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Via the pharyngotympanic tube
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Walls of middle ear
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Tegmental
jugular membranous anterior |
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Tegmental wall of middle ear
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Roof
thin bony wall separating middle ear from middle cranial fossa |
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Jugular wall
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Floor of middle ear
thin bony wall separating middle ear from internal jugular v contains tympanic canaliculus |
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Membranous wall
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lateral wall of middle ear
consists almost entirely of tympanic membrane |
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anterior wall of middle ear - what does it do and what does it contain?
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lower thin bony wall separates middle ear from int carotid a
Contains: opening of canal of tensor tympani m entrance of pharyngotympanic tube foramen for exit of chorda tympani foramen for exit of lesser petrosal n |
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Labyrinthine wall - which wall is it
what does it separate what does it contain |
medial wall
separates middle and inner ear contains: promontory that is formed by basal turn of cochlea oval window to which the foot of stapes is attached round window prominence of facial canal prominence of lateral semicircular canal |
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mastoid wall
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posterior wall of middle ear
lower bony wall between middle ear and mastoid air cells superiorly continuous with aditus to mastoid air cells contains: pyramidal eminence (stapedius tendon) opening for chorda tympani entering ear |
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Mastoiditis
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?
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Auditory ossicles
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malleus
incus stapes |
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where does chora tympani pass through middle ear
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between incus and malleus
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Where must surgical incision in tympanic membrane be made
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posterior inferior quadrant
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transmission of sound wavees in middle ear
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sound impacts on tympanic membrane
moves ossicles which move the oval window moves perilymph in scala vestibuli and scala tympani pressure relieved at round window wave causes activation of receptors in spiral organ which is translated as sound |
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what is sound transmission modulated by
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Attenuated by:
tensor tympani stapedius |
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tensor tympani
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attached to malleus
supplied by n to medial pterygoid (br of V3) |
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stapedius
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attached to stapes
supplied by n to stapedius (br of CN VII) |
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equilibration of pressure
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relieved through nasal or oral cavity
relieved through pharyngotympanic tube (eustachian) blockage can be due to illness or developmentally (tube smaller and more horizontal in kids) |
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Inner ear
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entirely within petrous part of temporal bone
bony labyrinth membranous labyrinth all structures associated with fluid and changes in fluid movement |
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Bony labyrinth - what does it consist of and what is it filled with
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Ocnsists of:
vestibule cochlea semicircular canals lined with periosteum filled with perilymph contains the membranous labyrinth |
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membranous labyrinth - what is it made of and what is it filled with
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consists of:
semicircular ducts (ant, post, lat) cochlear duct utricle saccule filled with endolymph |
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cochlea
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organ of heairng
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vestibular apparatus - what does it contain
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organs of balance
ant semicircular duct post semicircular duct lateral semicircular duct utricle saccule |
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How do the semicircular ducts work
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Their crista detect direction of movement (change in angular)
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How does the utricle work
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Its macula detects centrifugal and vertical acceleration
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How does the saccule work
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its macula detects linear acceleration
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How to treat glossopharyngeal neuralgia
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Sectioning or surgical decompression within jugular foramen
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Clinical signficance of occipital sinus
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Communicates inferiorly through foramen magnum with internal vertebral plexus providing path for spread of tumor cells or infection
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What does the bone of the orbital plate of the ethmoid separate
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Cavity of the orbit from the spaces of the ethmoidal air cells - paper thin
Orbital cellulitis may result from ethmoidal sinusitis |
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Surgical approach to eye
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Via lateral wall
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What does the nasal septum do
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Divides the chamber of the nose into 2 nasal passages
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What are the anterior and posterior openings of the nose
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Anterior - nares
Posterior - choanae |
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What does the external nose consist of
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2 nasal bones
frontal processes of maxillae 2 lateral nasal cartilages nasal septal cartilage 2 c shaped major alar carts 2-4 minor alar carts |
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What is the air space housed by the external nose called
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nasal vestibule
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What is the opening to the nasal cavities on the cranium
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Known as nasal (or piriform) aperture
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What is the anterior nasal spine
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The bony prominence known as the anterior nasal spine
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What forms the bony framework of the nasal cavities
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2 maxillae
2 nasals 2 palatines 2 lacrimals 2 inferior chonchae frontal ethmoid sphenoid vomer |
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What do the 2 choanae form
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Posterior nasal aperture
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Ethmoid bone - what does it form
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Forms majority of roof of nasal cavities and superior part of lateral walls
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Whhat does the perpendicular plate of the ethmoid form
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Superior portion of nasal septum
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What are the superior and middle nasal chonchae part of
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Ethmoid
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What are the scroll-shaped structures that project into the nasal cavity
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Inferior
Middle Superior nasal chonchae (turbinates) |
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Primary function of chonchae
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Increase SA of nasal mucosa
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What is the air space lateral and inferior to each conchae
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meatus
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What do the meatuses do
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Have openings for communication channels with paranasal sinuses and the orbit
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What is the lining of the nasal vestibule
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mucosa
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What are the internal portions of the nasal passages line with
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Either respiratory or olfactory mucosa
Olfatory mucosa is limited to lining superior nasal concha and adjacent part of septum (lined by olfactory epithelium and olfactory receptors) |
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What covers the majority of nasal passages
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respiratory mucosa
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What does the respiratory mucosa consist of
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Pseudostratified columnar epithelium w numerous goblet cells and seromucous glands
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What innervates seromucous glands
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Parasymp GVE carried in greater petrosal br of facial gland (and later n to pterygoid canal) that synapse in pterygopalatine ganglion
Postganglionic fibers join branches of the maxillary nerve to enter the nasal cavities |
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Where is the respiratory mucosa thickest
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Over the inferior and middle conchae and the region of the septum adjacent to the middle meatus
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Control of vascular plexuses in inferior and middle conchae
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Vascular plexuses can rapidly change their blood volume
Controlled by symp GVE fibers from T1 that synapse in superior cervical ganglion and postgang fibers join brs of the maxillary n or follow blood vessels |
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Nasal cycling
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Airflow through 1 nasal passage allows the other nasal passage to repair damage that results from conditioning of inspired air
So 1 nasal cavity is more congested than the other |
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Modification of respired air
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Particle filtration (dust and pathogens)
Olfaction Modification of temperature and moisture content of air upon inspiraiton and expiration |
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Arterial supply of nasal cavities
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Anterior and posterior (ethmoidal arteries) from ophthalmic a
Sphenopalatine and greater palatine arteries (maxillary artery) Lateral nasal and superior labial arteries (from facial artery) |
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Epistaxis
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Nosebleed
90% of them occur in the anterior inferior region - Kiesselbach's plexus or Little's area |
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Kiesselbach's plexus
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Numerous veins
Septal brs of anterior and posterior ethmoidal, greater palatine, sphenopalatine and superior labial aa anastomose there |
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What do nosebleeds in posterior area usually involve
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Rupture of sphenopalatine artery
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What do veins that accompany maxillary artery brs drain into
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Pterygoid plexus of veins
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Where do veins from anterior regions of nasal cavities drain into
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Facial vein
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Where do veins that accompany the anterior and posterior ethmoidal arteries drain
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Into ophthalmic vein which drains into cavernous sinus
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Where does an additional nasal vein in foramen cecum drain
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Into superior sagittal sinus
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What innervates the nasal septum
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Anterior ethmoidal (V1) and nasopalatine nerves (V2)
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What innervates the lateral nasal wall
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Anterior ethmoidal nerves (V1)
Posterior lateral nasal nerves (V2) |
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What do olfactory receptor neurons give rise to
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Roughly 20 olfactory nerves on each side that pass through cribiform plate of ethmoid and enter the olfactory bulbs
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What are the paranasal sinuses
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Frontal sinuses
Maxillary sinuses Sphenoid sinuses Ethmoid air cells |
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Where does the nasolacrimal duct drain
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Into inferior meatus
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What does the hiatus semilunaris and waht does it contain
|
In middle meatus
Openings of: frontonasal duct (infundibulum) ant ethmoidal air cells maxillary sinus |
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Where do the middle ethmoidal air cells open
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On bulla ethmoidalis in middle meatus
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Where do posterior ethmoidal air cells drain
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Into superior meatus
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Deviated septum
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Displacement of nasal septum that occurs where perpendicular plate of ethmoid articulates with vomer
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Nasal polyps
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Abnormal growths of tissue that arise from nasal mucosa
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Rhinitis
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inflammation of nasal mucosa
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Sinusitis
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inflammation of one or more paranasal sinuses
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Rhinosinusitis
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inflammation of both nasal mucosa and sinuses
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Nasopharynx
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Region of pharynx posterior to choanae and above level of soft palate
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What forms the roof of the nasopharynx
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Body of the sphenoid and basilar part of occipital
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What does the mucosal covering of the roof of the nasopharynx contain
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Pharyngeal tonsil
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What is adenoids
|
Enlarged pharyngeal tonsil
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What tonsils are the nasopharynx and oropharynx home to
|
Pharyngeal tonsil
Tubal tonsils Palatine tonsils Lingual tonsil |
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Waldeyer's ring
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Rings of lymphoid tissue around nasal and oral openings of pharynx formed by tonsils
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Names for eustachian tube
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Pharyngotympanic
Auditory |
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Where is the pharyngeal opening of the eustachian tube
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on lateral wall of nasopharynx
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What does the pharyngotympanic tube do
|
Connects middle ear with nasopharynx
Equalizes pressure on both sides of the tympanic membrane |
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1 x 5 =
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5
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Where is the pterygopalatine fossa
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Between pterygoid process of sphenoid bone posteriorly and maxilla anteriorly
Between nasal cavity medially and infratemporal fossa laterally |
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How does the pterygopalatine fossa communicate with the infratemporal fossa
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Laterally via the pterygomaxillary fissure
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How does the pterygopalatine fossa communicate with the nasal cavity
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Medially via sphenopalatine foramen
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How does the pterygopalatine fossa communicate with orbit
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Superiorly via inferior orbital fissure
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How does the pterygopalatine fossa communicate with the middle cranial fossa
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Through foramen rotundum
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How does the pterygopalatine fossa communicate with foramen lacerum
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Via pterygoid canal
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How does pterygopalatine fossa communicate with the oral cavity
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Through palatine canals
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How does the pterygopalatine fossa communicate with the nasopharynx
|
Via the palatovaginal canal
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What forms the medial wall of the pterygopalatine fossa
|
Perpendicular plate of the palatine bone
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WHat is the opening into the nasal cavity from the pterygopalatine fossa
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Sphenopalatine foramen
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Where are the pterygopalatine ganglion and brs of maxillary n
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Pterygopalatine fossa
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Where is the 3rd pt of the maxillary artery
|
PG fossa
distal to lateral pterygoid muscle enters PG fossa via pterygomaxillary fissure 6 brs |
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Branches of 3rd pt of maxillary
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Post sup alveolar
Infraorbital A of pterygoid canal pharyngeal greater palatine sphenopalatine |
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Path of a of pterygoid canal
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Passes posteriorly through pterygoid canal to nasopharynx
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Path of pharyngeal a
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traverses palatovaginal canal to nasopharynx
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Path of greater palatine a
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Descends through greater palatine canal with greater palatine n, giving off lesser palatine artery
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What does the greater palatine a supply
|
Hard palate
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What does the lesser palatine a supply
|
Soft palate
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Path of sphenopalatine a
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Passes through sphenopalatine foramen to supply nasal cavity
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Roots of trigeminal n
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Lg sensory
Small motor Within cranial cavity |
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What is the ganglion of CN V and where is it
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Trigeminal (semilunar or gasserian)
On sensory root on floor of MCF |
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What are the foramena through which the brs of CN V exit
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V1 - SOF
V2 - FR V3- FO |
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Path of V2
|
Maxillary n exits cranial cavity through FR to enter PG fossa
only sensory |
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Where is the pterygopalatine ganglion
|
Suspended from maxillary n within the PG fossa
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What does V2 become and when
|
Becomes infraorbital n after traversing the inferior orbital fissure
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Zygomatic n - br of ? and opening it goes through
|
v2
IOF |
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Nasal brs - br of? opening through?
|
sphenopalatine foramen
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Posterior superior alveolar n - what is it a br of and what does it traverse
|
Br of V2
traverses pterygomaxillary fissure |
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infraorbital n
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br of V2
traverses IOF |
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pharyngeal n - what is it a branch of and what does it traverse
|
br of v2
traverses palatovaginal canal |
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ganglionic brs to PG ganglion
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brs of V2
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greater and lesser palatine nn
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brs of V2
traverse greater and lesser palatine canals |
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brs of maxillary n
|
zygomatic
nasal brs post sup alveolar n infraorbital n pharyngeal ganglionic brs greater palatine lesser palatine |
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Path of zygomatic n
|
Enters orbit through IOF
Enters zygomatic foramen Divides into: zygomaticofacial n zygomaticotemporal n |
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Zygomaticofacial n
|
Br of zygomatic (V2)
emerges onto face via zygomaticofacial foramen |
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Zygomaticotemporal n
|
Br of zygomatic (V2)
Has communicating br to lacrimal n (V1) Enters temporal region via zygomaticotemporal foramen |
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Nasal brs of maxillary n
|
Enter nasal cavity through sphenopalatine foramen
Distribute as: superior posterior lateral nasal inferior posterior lateral nasal nasopalatine |
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Nasopalatine n
|
Br of nasal brs (V2)
Courses along nasal septum Passes through incisive canal/foramen to anterior palate |
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what innervates the maxillary teeth
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Superior alveolar nn
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Superior alveolar nn
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Posterior superior alveolar
Middle sup alveolar Ant sup alveolar |
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Posterior superior alveolar n
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Direct br of maxillary n
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Middle superior alveolar n - what is it a branch of and where
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Br of infraorbital n in infraorbital groove
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Anterior superior alveolar n - br of?
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Br of infraorbital n in infraorbital canal
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Infraorbital n
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Continuation of maxillary n at inferior orbital fissure where it exits the PG fossa to enter orbit
Courses along infraorbital groove where it gives rise to middle superior alveolar n enters infraorbital canal, where it gives rise to anterior superior alveolar n emerges thourhg infraorbital foramen and supplies: nasal brs inferior palpebral brs superior labial brs |
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PG ganglion
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Postgang symp and sensory fibers from V2 also traverse without synapsing
Suspended from maxillary n in PG fossa by ganglionic brs |
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Greater petrosal n - what is it a branch of and where
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Br of facial n at geniculate ganglion
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Deep petrosal n - what does it branch from
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Branches from internal carotid plexus
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N to pterygoid canal
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Formed by greater and deep petrosal nn
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Innervation of lacrimal gland
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Via postganglionic parasymp fibers from pterygopalatine ganglion and postganglionic sympathetic fibers from sup cervical symp ganglion; fbers reach maxillary n via ganglionic brs
from maxillary n enters the zygomatic n and its zygomaticotemporal br passes via communicating br to lacrimal n(V1) postgang parasymp fibers are secretomotor to lacrimal gland postgang symp fibers are vasomotor to lacrimal gland |
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Innervation of palate
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Lesser palatine n (lesser palatine canal/foramen)
Greater palatine n (grater palatine canal/foramen) Nasopalatine n (Incisive canal/foramen) |
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Functional components of facial n
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SVE: mm of facial expression, stapedius, stylohyoid, posterior belly of digastric
SVA: taste from anterior 2/3 of tongue, floor of mouth, palate GSA: from skin of external acoustic meatus GVE: parasymp innervation to PG and subman ganglia |
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Path of facial n
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Exits cranial cavity through internal acoustic meatus to enter facial canal
Has geniculate ganglion at genu of facial n where greater petrosal n branches descends in facial canal in posterior wall of tympanic cavity gives off nerve to stapedius and chorda tympani exits skull through stylomastoid foramen to enter parotid gland gives brs to post belly of digastric and stylohyoid mm gives rise to posterior auricular n brs into: temporofacial cervicofacial |
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terminal brs of facial n
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temporal
zygomatic buccal mandibular cervical |
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What happens in lower motor neuron lesion of facial n
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Paralysis of ipsilateral muscles of facial expression
Can't close eyelids, loss of facial folds, drooping corner of mouth |
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Oral cavity
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Opens to face through oral fissure
Continuous with pharynx at oropharyngeal isthmus |
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Division of oral cavity
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Dental arches divide oral cavity into:
oral vestibule oral cavity proper |
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Oral vestibule
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Between dental arches and cheeks and lips and
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Oral cavity proper
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Enclosed by dental arches
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What forms the roof of the oral cavity
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Hard and soft palates
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What forms the floor of the oral cavity
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Mylohyoid and geniohyoid mm and tongue
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What forms lateral walls of oral cavity
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Buccinator muscle
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Bones contributing to skeletal framework of oral cavity
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Maxillae
Palatines Sphenoid Temporals Hyoid Mandible |
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Mandible
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Horizontal body and ascending ramus meet at angle of mandible
Superior part of body that holds teeth is called alveolar part of mandible Mental spines (tubercles) on ant surface of mandibular ramus are important for muscle attachments |
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How many incisors
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8
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how many canine teeth
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4
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How many premolars
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8
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how many molars
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12
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What innervates upper dentition
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Anterior, middle, posterior superior alveolar nn (V2)
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What innervates the lower dentition
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Inferior alveolar n (V3)
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What forms the cheeks
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buccinator m, which holds the cheeks against the alveolar araches and keeps food bw teeth while chewing
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What innervates the buccinator
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buccal brs of facial n
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What carries sensation from skin and oral mucosa of cheeks
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Buccal n - br of mandibular (V3)
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What do the geniohyoid and mylohyoid do
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Depress mandible when hyoid is fixed and elevate and pull the hyoid forward when mandible is fixed
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Innervation of mylohyoid
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N to mylohyoid from inferior alveolar br of V3
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Innervation of geniohyoid
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Br of cervical n C1
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Where are the salivary glands
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On floor of oral cavity
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Apex of tongue
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Directed anteriorly and sits immediately behind incisors
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Root of tongue - attachments
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attached to mandible and hyoid bone
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Oral part of tongue
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Anterior 2/3
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Pharyngeal part of tongue
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Posterior 1/3
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Terminal sulcus of tongue
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separates oral and pharyngeal parts of tongue
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Foramen cecum
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small depression in apex of terminal sulcus that marks where the epithelium invaginated to form thyroid gland
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what covers the tongue
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Papillae - increase its SA
all except filliform have taste buds |
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Intrinsic tongue mm
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originate and insert within substance of the tongue
alter the shape of the tongue by lengthening and shortening it, by curling and uncurling its apex and edges, and by flattening and rounding its surface |
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Extrinsic tongue mm
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Originate from structures outside the tongue and insert onto the tongue
Protrude, retract, depress, and elevate the tongue |
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Genioglossus mm
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Fan shaped
Make up large pt of tongue originate from superior mental spine and the body of the hyoid Depress the central part of the tongue and protrude the anterior part of the tongue innervated by hypoglossal nn |
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hyoglossus mm
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thin, quadrangular shaped mm lateral to genioglossus mm
originate from entire length of greater horn of hyoid depress the tongue and are innervated by hypoglossal nn |
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styloglossus mm
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originate from anterior surface of styloid process of temporal bones and enter tongue at superior margin of hyoglossus mm
retract the tongue and are innervated by hypoglossal nn |
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nerves that innervate tongue
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V3
VII IX XII X |
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What is the hard palate formed from
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Separates oral cavity from nasal cavity
Formed from palatine processes of the maxillae and the horizontal plate of the palatine bones |
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Soft palate formation
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Acts as valve that can be depressed to help close the oropharyngeal isthmus or elevated to separate the nasopharynx from the oropharynx
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palate innervation
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greater and lesser palatine nerves and nasopalatine n (V2)
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blood supply of palate
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greater and lesser paltine aa (from maxillary)
ascending palatine a and palatine br of ascending pharyngeal a (from facial a) |
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What mm contribute to the soft palate
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Tensor veli palatini
Levator veli palatini Palatoglossus Palatopharyngeus musculus uvulae |
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tensor veli palatini and levator veli palatini - how do they get to palate
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descend into palate from base of skull
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palatoglossus and palatopharyngeus
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ascend into palate from tongue and pharynx, respectively
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musculus uvulae
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associated with uvula
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tensor veli palatini
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descends from scaphoid fossa of sphenoid, hooks around pterygoid hamulus and expands to form palatine aponeurosis
tenses soft palate and opens pharyngotympanic tube during yawning and swallowing innervated by br of V3 |
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levator veli palatini - attachments, action, and innervation
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descends from petrous portion of temporal bone and attaches to superior surface of palatine aponeurosis
elevates the soft palate above the neutral position innervated by pharyngeal br of X via pharyngeal plexus |
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palatopharyngeus
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arises on superior surface of palatine aponeurosis and descends to attach to pharyngeal wall
depresses palate, moves palatopharyngeal arch toward midline and elevates pharynx innervated by phayngeal br of X via pharyngeal plexus |
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Palatoglossus
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extends from inferior surface of palatine aponeurosis to lateral surface of tongue
depresses palate, moves palatoglossal arch toward the midline and elevates the back of the tongue innervated by pharyngeal br of X via pharyngeal plexus |
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Musculus uvulae - where does it originate
what is its action what is its innervation |
Originates on the posterior nasal spine, passes dorsally over the palatine aponeurosis and inserts into CT of uvula
elevates and retracts the uvula innervated by pharyngeal br of X via pharyngeal plexus |
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Where is the oropharynx
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posterior to the oral cavity, inferior to the level of the soft palate and superior to the upper margin of the epiglottis
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What do the palatoglossal arches do
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overly the palatoglossal mm and mark the site of the oropharyngeal isthmus
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What do the palatopharyngeal arches overlie
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palatopharyngeus mm
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Where are the palatine tonsils
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on lateral wall of oropharynx bw palatoglossal and palatopharyngeal arches
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What surround the pharynx
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3 constrictor mm
superior middle inferior |
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Constrictor mm
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contract sequentially from top to bottom as in swallowing to mvoe a bolus of food through the pharynx and into the esophagus
All innervated by pharyngeal br of vagus n |
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Swallowing
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movements of mm of tongue and soft palate compress the bolus of food against the palate and push it into the mouth into the oropharynx
soft palate is elevated, sealing off the nasopharynx from the oropharynx. Larynx is elevated and pulled forward, thereby widening and shortening the oropharynx sequential contraction of all 3 pharyngeal constrictor mm forces the bolus into the esophagus 1st step is voluntary and other 2 are not |
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What is the pharynx
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common chamber of respiratory and digestive systems
Wider superiorly, that extends from the base of the skull to the inferior border of the cricoid cartilage |
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Subdivisions of the pharynx
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Nasopharynx
Oropharynx Laryngopharynx |
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Where is the nasopharynx
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Above the soft palate posterior to the nasal cavities
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Where is the oropharynx
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Extends from the soft palate to the upper border of the epiglottis
behind the oral cavity and dorsum of the tongue |
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Where is the laryngopharynx
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From upper border of epiglottis to the inferior border of the cricoid cartilage where it is continuous with the esophagus
behind the inlet and posterior wall of the larynx |
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What are the piriform recesses
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Sites where food or foreign objects may become lodged and may damage the internal laryngeal nerves just deep to the mucous membrane; nerves may be damaged in attempts to remove objects; nerves may be anesthetized for endoscopy
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Retropharyngeal space
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Behind the pharynx
Potential space between buccopharyngeal and prevertebral fascia Provides pathway for spread of infection from base of skull into mediastinum, where it may result in fatal mediastinitis may be site of abscess formation, producing difficulty breathing and/or swallowing; if a retropharyngeal abscess ruptures the pharyngeal wall, it may cause aspiration pneumonia |
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Where is the larynx
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Between pharynx and trachea
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Functions of larynx
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Passage of air to and from lungs
To prevent foreign objects from entering lower respiratory passages In phonation/voice production |
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Skeleton of larynx
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Thyroid cartilage
Cricoid cartilage Arytenoid cartilages Epiglottic cartilage Corniculate cartilages Cuneiform cartilages |
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What are the more prominent cartilages of the larynx
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Thyroid cartilage (Adam's apple)
Cricoid cartilage |
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Thyroid cartilage
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Forms laryngeal prominence/Adam's apple
consists of 2 laminae fused in midline anteriorly forms bilateral cricothyroid joints with the cricoid cartilage below, allowing the thyroid cartilage to tilt forward and backward on it |
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What accounts for lower male voice
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Smaller angle of laminae of thyroid cartilage
Longer vocal ligaments |
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Cricoid cartilage
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shaped like a signet ring with the broad lamina located posteriorly and the thinner arch in front
articulates with the thyroid cartilage at bilaterateral cricothyroid joints attached superiorly in the thyroid cartilage in front and to the arytenoid cartilages behind by the cricothyroid ligament |
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What is the cricothyroid ligament
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cricovocal membrane, conus elasticus
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What is the vocal ligament
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Superior free border of cricothyroid ligament
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Where might an emergency airway be made
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anterior midline at median cricothyroid ligament (cricothyrotomy)
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What is the cricoid cartilage a useful landmark for
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Locating structures in neck:
Cv6 and carotid tubercle, its enlarged anterior tubercle where the common carotid a may be compressed vertebral a entering the transverse foramen of Cv6 sometimes, middle cervical sympathetic ganlgion |
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Arytenoid cartilages
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paired, pyramidal shaped cartilages that articulate with superior border of cricoid cartilage lamina
Each has apex, muscular process, and vocal process |
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Where is the vocal ligament
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Attached to the vocal process of the arytenoid cartilage
attaches anteriorly to thyroid cartilage and posteriorly to arytenoid cart |
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3 movements of arytenoid cart
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Sliding toward or away from each other
Tilting anteriorly or psoteriorly around horizontal axis Rotating around vertical axis |
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Epiglottic carti - attached to what and by what?
What does it form? |
Attached to hyoid bone by hyoepiglottic ligament and to thyroid cart by thyroepiglottic ligament
covered by mucous membranes to form the epiglottis |
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Epiglottis - what does it do
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pushed back and down over the laryngeal inlet during swallowing to help prevent the entrance of food and drink into larynx
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FOlds of larynx
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2 pairs of lateral folds internally separated by spaces, the ventricles
Vocal folds (true vocal cords) inferiorly vestibular folds (false vocal cords) superiorly |
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What is the superior free border of the cricothyroid lig
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vocal ligament
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what does the quadrangular membrane have
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aryepiglottic lig at its superior free border and the vestibular lig at its inferior free border
each lig forms the core of a fold of the same name |
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What are landmarks during laryngoscopy
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corniculate and cuneiform cartilages
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Divisions of laryngeal cavity
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Vestibule
ventricle infraglottic cavity |
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vestibule of larynx
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above vestibular folds
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ventricle of larynx
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between vestibular and vocal folds
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infraglottic cavity
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inferior to vocal cords, located between them and trachea
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What does a cricothyrotomy open into
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Opens emergency airway into infraglottic cavity
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What happens when a foreign object is aspirated
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It contacts the mucous membrane of the vestibule, provokes a reflex of coughing in order to try to expel it
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What is the laryngeal saccule
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Blind pocket of ventricle, anterosuperiorly
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laryngocele
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Enlarged largneal saccule that protrudes through the thyrohyoid membrane
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What is the core of the vocal fold
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vocal ligament - extends anteriorly from the vocal process of the arytenoid cartilage to the thyroid cartilage
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What alters the position and tension of the vocal ligaments
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Movements of arytenoid cart and thyroid cart
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What is the space between the vocal folds
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rimaglottiidis
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What is the glottis
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the rima glottidis plus the vocal folds
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What are the only laryngeal mm that abduct the vocal folds
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posterior cricoarytenoid mm
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what happens if the psoterior cricoarytenoid mm are paralyzed B/L and what might they be injured by
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e.g. by lesion of recurrent laryngeal nn
vocal folds may meet in midline and make speaking and breathing difficult or impossible |
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Adduction of vocal folds
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?
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valsalva maneuver
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attempted expiration against a closed airway
vestibular and vocal folds are tightly adducted following a deep inspiration; strong contraction of abs increases intra abdominal pressure and elevates diaphragm, increasing intrathoracic pressure impedes venous return to heart retinal hemorrhage could happen |
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what innervates the intrinsic mm of larynx
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vagus nn
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what does the recurrent laryngeal brs innervate
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all intrinsic mm of of larynx except cricothyroid
nn related superiorly to inferior thyroid aa |
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what do the external laryngeal brs innervates and what do they descend with
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cricothyroid mm
descend with superior thyroid aa |
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What is sensory to the mucous membrane inferior to the vocal folds
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recurrent laryngeal brs
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what is sensory to the mucous membrane superior to vocal folds
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internal laryngeal brs
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What happens if the internal laryngeal nerves are damaged
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laryngeal mucosa of vestibule is anesthetized and the protective mechanism to keep foreign bodies out of larynx is lost
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