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387 Cards in this Set
- Front
- Back
What is the scalp composed of?
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Skin, Connective tissue, Aponeurosis, Loose areolar tissue, Periosteum
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What is the vascularization of the skin and connective tissue of the scalp?
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Very vascular
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What is the aponeurosis of the scalp?
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Strong sheath covering skull. Attachment for muscles
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What is loose areolar tissue of the scalp?
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Allows for free movement of scalp. Communicates w/ interior. Potential space: "danger area" for infection (eg infected hair follicle) could potentially communicate w/ interior - may spread through emissary veins to meninges
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What is the purpose of the cranium?
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Houses brain (neurocranium) and viscera of head (viscerocranium, facial skeleton)
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What are the 9 bones of the cranium?
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Frontal, Zygomatic, Maxilla, Mandible, orbit, sutures, pterion, nasal bone, pneumatized bones
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What is the area of the frontal bone and what nerve supplies it?
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Supraorbital fissure. VI - first branch of trigeminal
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What are the types of fractures that can happen in the frontal bone?
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Depressed skull fracture, high impact - blunt trauma, palpable defect in skull
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What is the zygomatic bone?
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Cheek bone
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What are the characteristics of fractures of the zygomatic bone?
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Can cause diplopia due to EO muscle entrapment. 2nd most common fascial fracture, can occur in assaults, MVA, sports, results in flat midface, decreased ability to open mouth.
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What is the maxilla?
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Upper jaw bone. Has infraorbital forament for nerve V2 and vessels.
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What are some characteristics of fractures of the maxilla?
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High-energy blunt force injury, MVA, falls. LeFort fractures = midface fracture
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What is the mandible?
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Bottom portion of jaw. Mental foramen where mental nerve (V3) enters face
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What is the characteristic of a fracture of the mandible?
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Usually two injuries: two fractures or a fracture and dislocation
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What is the orbit? (4 walls)
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Floor is roof of maxillary sinus. Medial wall is ethmoid bone. Lateral wall is zygomatic and sphenoid bones. Superior wall is frontal bone (sinus)
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What are the characteristics of a fracture of the orbit?
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Blowout fracture. Diplopia due to EO muscle entrapment. Prolapse of orbital contents into sinus (Enophthalmos)
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What are the 5 sutures/ regions of skull?
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Coronal, Sagittal, Lambdoidal, Bregma, Lambda
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What is the coronal suture?
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Anterior lateral, like a crown. Mostly separates frontal from two parietal bones.
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What is the sagittal suture?
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Down the midline (between parietal bones)
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What is the lambdoidal suture?
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Posterior - separates parietal bones from occipital bone
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What is the bregma of the skull?
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Region of intersection between coronal and sagittal sutures. This is the anterior fontanel in infacy.
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What is the lambda of the skull?
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Region of intersection between the lambdoidal and sagital sutures. This is the posterior fontanel in infancy.
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What is the pterion?
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Area of weakness at junction of sphenoid, temporal, frontal and parietal bones.
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What structure can be injured in a blow to the pterion?
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The middle meningeal artery - it lies under the pterion region.
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What is the nasal bone?
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Two small midline bones. Form bridge of nose.
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What are the characteristics of nasal bone fractures?
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Most common fractured bone of the face. Mostly happens in altercations.
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What are pneumatized bones?
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Bones of facial skeleton w/ air sinuses. Includes frontal, temporal, sphenoid and ethmoid bone (portion of maxilla). Paranasal sinuses.
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What are the muscles of facial expression?
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Occipital frontalis, Orbicularis oculi, Platysma, Orbicularis oris, Zygomaticus major
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What facial expression does occipital frontalis make?
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Elevated eyebrows and wrinkling brows
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What facial expression does orbicularis oculi make?
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Closed eyelids
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What facial expressions are made by the platysma?
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Tenses skin of anterior neck, depress mandible
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What facial expression is made by orbicularis oris?
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Closes mouth
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What facial expression is made by zygomaticus major?
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Smiling
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What is the innervation of muscles of facial expression?
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CN VII
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What are 3 chracteristics of facial lacerations?
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No deep fascia, loosely attached tissues, lacerations tend to gape and may scar
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What are the 4 muscles of mastication?
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Masseter, Temporalis, Pterygoids, Buccinator
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What is a characteristic of the masseter muscle?
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Parotid duct sits anterior to this muscle
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What is a characteristic of the temporalis muscle?
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Fills temporal fossa (accessory)
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What is a characteristic of the pterygoids?
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Includes Medial and lateral (accessory)
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What is a characteristic of the buccinator?
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The parotid ducts pierces this muscle on the way to the oral cavity.
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What is the innervation of the muscles of mastication?
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CN V3 for all of them except the buccinator. The buccinator is innervated by CN VII.
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What nerve is responsible for sensory innervation of the face?
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Trigeminal Nerve (CN V): V1, V2 and V3
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What is the other name for V1 of the trigeminal nerve? What are the branches?
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Ophthalmic nerve. Branches: supraorbital nerve and supratrochlear nerve
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What is the other name for V2 of the trigeminal nerve? What branches from it?
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Maxillary nerve. Branch: infraorbital nerve
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What is the other name for V3 of the trigeminal nerve? What branches from it?
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Mandibular nerve. Branch: Mental nerve
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Where would you administer anesthesia into each of the 3 branches of the trigeminal nerve?
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CN V1: toward the foramen but not in.
CN V2: 1 cm inferior to the infraorbital foramen CN V3: 1.5 cm posterior and lateral to the foramen and directly toward the foramen |
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What are the 3 salivary glands?
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Parotid, Sublingual, Submandibular
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What are the characteristics of the parotid gland?
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CN VII lies very close in relation. Large. Superficial. Pierces buccinator and enters the oral cavity. Delivers saliva via the Stenson's duct. Can be occluded by stone or inflammation.
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What is a characteristic of the sublingual gland?
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Lies in floor of mouth and has numerous small openings into oral cavity.
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What is a characteristic of the submandibular gland?
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Lies inferior to mandible and open into oral cavity via Wharton's duct
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What is Stenson's duct?
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The duct that delivers saliva into the mouth from the parotid gland.
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What is the Wharton's ducts?
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Ducts that deliver saliva into the mouth from the Submandibular gland
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What are salivary duct calculi?
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Stones that may obstruct the parotid duct causing pain and swelling in the gland served by the gland. Can sometimes break up with lemon drops. Most common place: Wharton's ducts. An infection can occur which would require abx and if stone doesn't break up or move on its own, may need surgery.
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What is the Parotid plexus?
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Nerve branches of the facial nerve
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What are the 5 branches of the facial nerve (parotid plexus)?
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Temporal, Zygomatic, Buccal, Marginal Mandibular, Cervical
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Where is the main trunk of the facial nerve?
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In the parotid gland
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What poses a risk of injury to all of the facial nerves?
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Parotidectomy, and submandibular gland excision
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What is the facial artery a branch from?
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External carotid artery
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What does the facial artery supply?
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Face
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Where you might feel pulsations of the facial artery?
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Mandibular region
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What is the significance of the transverse facial branch of the facial artery?
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Only look for it because the parotid duct goes w/ it and buccal branch of facial nerve. If you find one, can find other two.
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What is a possible problem with the facial vein?
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Blood from the facial veins may flow retrograde into cavernous sinus causing infection and thrombosis
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What is contained in the infratemporal fossa?
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Temporalis muscles, lateral and medial pterygoids, maxillary a, venous plexus, lingual n (CN V3), inferior alveolar n, chorda tympani n (CNVII)
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What is the innervation of the lingual n (CN V3)?
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Sensory to anterior 2/3 of tongue
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What is the innervation of the alveolar nerve?
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teeth
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What is the innervation of the chorda tympani n (CN VII)?
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Taste to anterior 2/3 of tongue
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What is the calvaria?
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Cranium minus face and mandible. Skullcap: frontal, temporal and parietal bones
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What is the cranial fossa?
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Think of these as "bowls with holes." Spaces w/in the internal surfaces of cranial base.
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What is the anterior cranial fossa?
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The front "bowl" of the cranial fossa. Formed by the frontal bones (orbital regions)
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What is contained in the anterior cranial fossa?
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Frontal lobes of brain and olfactory bulbs.
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What hole is in the anterior cranila fossa?
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Cribiform plates w/ foramina: passage of olfactory nerves into nasal cavity.
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What is the bony portion of the anterior cranial fossa?
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Crista galli which is the bony ridgge
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What are the broad extra ocular muscles and what is significant about them?
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One levator, four recti, and two obliques. NONE of these muscles work independently. They all exert pull on each other and affect each others function
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What is abduction of the eye?
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Movement of the pupil outward
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What is adduction of the eye?
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Movement of the pupil inward
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What is elevation of the eye?
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Movement of the pupil upward
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What is depression of the eye?
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Movement of the pupil downward
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What is intorsion of the eye?
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Rotation of the top of the eye toward the nose (medial rotation)
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What is extorsion of the eye?
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Rotation of the top of the eye away from the nose (lateral rotation)
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What is the action and innervation of the levator palpebrae?
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Elevates upper lid. Innervation: CN III
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What is the action and innervation of the superior oblique? And what is a characteristic of it?
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Action: abducts, depresses and medially rotates the eye (intorsion).
Innervation: CN IV Characteristic: Goes through trochlea which changes angle of the SO muscle |
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What is the action and innervation of the superior rectus?
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Action: elevates, adducts and medially rotates (intorsion)
Innervation: CN VI |
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What is the action and innervation of the lateral rectus?
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Action: Abduction
Innervation: CN VI |
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What is the action and innervation of the medial rectus?
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Action: Adduction
Innervation: CN III |
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What is the action and innervation of the inferior rectus?
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Action: Depression, adduction, lateral rotation (extorsion)
Innervation: CN III |
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What is the action and innervation of the inferior oblique?
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Action: Abduction, elevation, lateral rotation (extorsion)
Innervation: CN III |
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What are the 5 nerves of the orbit?
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Optic nerve through optic canal (CN I)
Frontal nerve (V1 branches into supraorbital and supra trochlear) Trochlear nerve (CN IV) Abducent nerve (CN VI) Lacrimal nerve (V1 branch) |
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What is the lacrimal apparatus?
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The lacrimal apparatus is the physiologic system containing the orbital structures for tear production and drainage.
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What is the function of the lacrimal glands?
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Secrete tears
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What is the function of the lacrimal ducts?
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Bring fluid from the lacrimal glands into conjunctival sac
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Where do tears drain?
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The lacrimal pumctum drains tears through the lacrimal canals and into the lacrimal sac then into the nasolacrimal duct and into the inferior meatus of nose
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What is a lacrimal apparatus blockage?
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Presents as apparent increase in tearing due to blockage in nasolacrimal duct. "blocked tear duct"
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What bones form the middle cranial fossa (the middle "bowl")?
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Sphenoid bones and temporal bones
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What things are contained in the middle cranial fossa?
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Temporal lobes of cerebrum, pituitary gland (in hypophysial fossa of sella turcica)
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What are the portions of the middle cranial fossa?
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Sella turcica w/ central hypophysial fossa, superior orbital fissure (conducting CN III, IV, V1 and VI)
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What are the 6 holes in the middle cranial fossa?
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Optic canal, Foramen rotundum, Foramen ovale, Forament spinosum, Forament lacerum, Internal acoustic meatus
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What runs through the optic canal?
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CN II
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What runs through the foramen rotundum?
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CN V2
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What runs through the foramen ovale?
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CN V3
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What runs through the foramen spinosum?
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Middle meningeal bessels, CN V3 branch
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What runs through the foramen lacerum?
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Branches of middle meningeal artery
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What runs through the internal acoustic meatus?
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CN VII and VIII
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What problems could be caused by a pituitary adenoma?
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Could put pressure on a lot of the nerves in the middle cranial fossa and the meningeal arteries. Could affect vision, extraocular muscles and vasculature
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What bone forms the posterior cranial fossa?
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Occipital bone
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What is contained in the posterior cranial fossa?
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Cerebellum, pons and medulla
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What is the main portion of the posterior cranial fossa?
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Grooves for venous sinuses: sigmoid and transverse
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What are the holes in the posterior cranial fossa?
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Hypoglossal canal, foramen magnum, jugular foramen
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What runs through the hypoglossal canal?
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CN XII
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What runs through the foramen magnum?
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Brainstem and spinal cord, CN XI, vertebral arteries
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What runs through the jugular foramen?
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Cn XI, X and XI, internal jugular vein
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What is a cranial base fracture?
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Fracture at the base of the skull. May result in a dural tear. In fracture to the anterior cranial base, may be rupture of the internal carotid artery and fistula formation w/ cavernous sinus - causes eyeball protrusion (via opthalmic vein engorgement) as well as potential damage to nearby cranial nerves
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What is CSF ottorhea?
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Petrous portion of temporal bone fracture, in middle cranial fossa, "battle sign": bruising over the mastoid process - may suggest underlying brain trauma
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What is CSF rhinorrhea?
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Anterior cranial fossa fracture. Causes racoon eyes
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What is the epidural space?
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Above the dura, contains branches of medical meningeal artery
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What is the dura mater?
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Thick and tough, made of two layers: endosteum (periosteal), meningeal layer
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What are the 5 sinus areas in the cranium?
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Superior sagittal sinus, Strait sinus, Inferior sagittal sinus w/ great cerebral vein, transverse sinus-sigmoid sinus- jugular vein, cavernous sinus
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What does the cavernous sinus receive blood from?
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via the superior and inferior ophthalmic veins through the superior orbital fissure and from superficial cortical veins, and is connected to the basilar plexus of veins posteriorly.
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Where can sinus infections come from?
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Sphenoid sinuses
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Where can facial skin infections come from?
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Pimples and other skin infections can spread to the cavernous sinuses through the facial vein’s anastamoses with the ophthalmic vein and the pterygoid venous plexus.
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What is the subdural space?
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Doesn't really exist
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What is the arachnoid mater?
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Vascular layer, suparachnoid space is underneath it
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What is the subarachnoid space?
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Contains CSF which is made by the choroid plexus in the ventricles
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What is the pia mater?
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Densely adherent layer of the meninges. Not as obvious as a separate layer
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What could a mass in the cavernous sinus be?
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Internal carotid artery aneurysm, pituitary adenoma or meningioma
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What nerves might be affected by a mass in the cavernous sinus?
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CN II, III, IV, V 1 and V2, VI
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What effect might you see by compression of CN II due to a mass in the cavernous sinus?
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Visual field deficits
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What effect might you see by compression of CN III due to a mass in the cavernous sinus?
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Ptosis (droop of eyelid), loss of extra ocular muscles
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What effect might you see by compression of CN V1 and 2 due to a mass in the cavernous sinus?
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Sensory loss
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What effect might you see by compression of CN IV and VI due to a mass in the cavernous sinus?
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Loss of extra ocular muscles
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What is an epidural hematoma?
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Bleeding caused by tearing of the middle meningeal artery (fall or direct blow). Direct blow characterized by LOC followed by "lucid interval." Bleeding causes compression on brain parenchyma and must be surgically corrected. Treated early = good prognosis.
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What is a subdural hematoma?
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Subdural space doesn't really exist. Bleeding caused by tearing of cerebral veins at superior sagittal sinus. Characterized by persistent LOC, persistent neuro deficit.
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What is a subarachnoid hemorrhage?
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Usually occurs as a result of an aneurysm rupture (arterial) from head trauma. Characterized by signs of meningeal irritation: photophobia, headache, stiff neck and LOC. Prognosis depends on location.
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What are the three broad regions of the brain?
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Forebrain, midbrain and hindbrain
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What makes up the forebrain?
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Cerebrum, thalamus and hypothalamus, and limbic system
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What is the cerebrum?
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Largest portion of brain w/ four distinct lobes on each side and connect via corpus callosum and lateral ventricles
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What are the cerebral hemispheres?
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Right and left side. Connected by white matter mass: corpus callosum.
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What is the surface of the brain?
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Grey matter - cortex
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What is the parecentral gyrus?
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The convolution of the frontal lobe that is bounded in back by the central sulcus and that contains the motor area. Somatomotor strip (upper motor neuron)
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Where is the motor speech area and what is it called?
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Frontal lobe. Called Broca's
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What vessel supplies the motor speech area (broca's)?
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Left middle cerebral artery
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What are the 4 functions of the frontal lobe?
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Planning and organizing, problem solving, personality, "higher cognitive functions" including behavior and emotions
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What area does the parietal lobe contain?
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Postcentral gyrus: somatosensory strip
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What are the 2 functions of the parietal lobe?
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Visual-spatial relations, sensory perception
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What area does the occipital lobe contain?
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Calcarine sulcus - border of occipital lob: vision
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What is the function of the occipital lobe?
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Processing visual visual information
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What area does the temporal lobe contain?
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Superior temporal gyrus: hearing
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What is Wernicke's area?
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Area of temporal lobe that is receptive to speech and interprets speech?
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What is the function of the temporal lobe?
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Organizing sensory input, language
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What is the diencephalon?
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Region of the vertebrate neural tube which gives rise to posterior forebrain structures. Contains the thalamus and hypothalamus.
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What is the function of the thalamus?
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Relay sensory info
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What is the function of the hypothalamus?
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Control of pituitary gland, controls sleep and wake states, maintains homeostasis
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Where is the hypothalamus located?
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Find the thalamus and go inferior and slightly posterior
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What does the limbic system include?
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Hyppocampus and amygdala
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What are some of the functions of the limbic system?
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Visceral motor activity, controls emotions and memories. In extreme alcoholism, might see atrophy - loss of emotion
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What nerves supply the midbrain?
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CN III and IV
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What is the midbrain?
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Superior part of the brain stem, includes the cerebral aqueduct
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What is the hindbrain composed of?
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Pons, Medulla oblongata and Cerebellum
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What nerve supplies the pons?
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CN V
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What is the function of the pons?
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Visual relay center, sleep cycles (works w/ hypothalamus).
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What nerves are found at the junction of the pons and medulla?
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CN VI, VII and VIII
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What nerves supply the medulla oblongata?
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CN IX, X, XII
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What is the function of the medulla oblongata?
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Controls breathing, circulation
Sometimes where we define brain death - once the medulla oblongata is no longer functioning. Contains 4th ventricle |
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Where is the cerebellum?
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Below the tentorium cerebelli
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What is the basal ganglia?
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Deep nuclei that modify movement
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What is Parkinson's Disease?
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Movement disorder caused by a decrease in dopamine-secreting cells in Substantia Nigra. A disorder of the basal ganglia
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What is Huntington's Disease?
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Programmed degeneration of Basal Ganglia. It is autosomal dominant and causes irregular movement
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What are the three types of fibers in the white matter?
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Commissural fibers, Association fibers and Projection fibers
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What are the commissural fibers of the white matter?
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Connect the 2 hemispheres via the corpus collosum
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What are the association fibers of the white matter?
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Connect areas in the same hemisphere
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What are the projection fibers of the white matter?
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Connect cortex w/ lower brain and spinal cord
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What are the upper motor neurons?
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Cortical neurons that innervate lower motor neurons
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What are the two tracts of the upper motor neurons?
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Corticospinal tract and corticobulbar tract
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What is the corticospinal tract a part of? What is its path?
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Upper motor neurons. Begins in somatomotor cortex and ends at the spinal cord
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What is the corticobulbar tract a part of and what is its path?
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Upper motor neurons. Begins in somatomotor cortex and ends at cranial nerves
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What 4 things can occur due to an upper motor neuron lesion?
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Weakness, mild atrophy from disuse, increased deep tendon reflexes, increased tone
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What is a Positive Babinski sign?
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It is an increased deep tendon reflex due to an upper motor neuron lesion. It is the fanning of lateral toes and dorsiflexion of the great toe.
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What do lower motor neurons do?
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Directly innervate skeletal muscle
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Where are lower motor neurons located?
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Cell bodies are located w/in the ventral horns of the spinal cord and w/in the brainstem motor nuclei
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What causes a lower motor neuron lesion?
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Either a cranial nerve problem or spinal cord problem
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What 5 things would you see in a lower motor neuron lesion?
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Weakness, atrophy pronounced, fasciculations, decreased or absent deep tendon reflexes, decreased tone
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What would you see in a peripheral nerve lesion?
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Loss of all function on one side
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Where is CSF made?
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By choroid plexus of the ventricles
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What are the lateral ventricles?
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There are two, one in each cerebral hemisphere. The choroid plexus is within them.
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What is the interventricular foramen?
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Opening of each lateral ventricle into the third ventricle
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What is the third ventricle?
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Very small ventricle between diencephalons
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What is the cerebral aqueduct?
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Connects the 3rd and 4th ventricles
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What is the 4th ventricle?
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Shaped like a triangle between cerebellum and brainstem
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What is the central canal?
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Continuation of ventricular system into spinal cord. There is some CSF that goes into subarachnoid space around spinal cord. Most CSF into cisterns (lateral and medial aperatures) back to venous sinus absorbed through arachnoid granulations
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What is hydrocephalus?
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Accumulation of CSF in the cranium due to overproduction of blockage of flow/ absorption or not enough drained. Results in ventricular dilation and increased intracranial pressure.
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Where can a blockage occur causing hydrocephalus?
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Cerebral aqueduct or intraventricular foramen
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What is the treatment for hydrocephalus?
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Surgical intervention in the form of a shunt - allows for depressurization of the system
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What is the circle of willis?
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Arises from internal carotid arteries and vertebral arteries
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What is the path of the internal carotid arteries?
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Goes through cavernous sinuses w/ CN VI, III, and IV Branches to form the anterior circulation of the brain
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What are the branches that form the anterior circulation of the brain off of the internal carotid arteries?
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Anterior cerebral arteries (frontal), middle cerebral arteries (temporal) - very important!, Anterior communicating artery, posterior communicating artery
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What is the path of the vertebral arteries?
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First branches off of subclavian arteries. They go up through the transverse foramen of the cervical vertebrae. They branch to form the posterior circulation of the brain.
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What are the branches off of the vertebral arteries that form the posterior circulation of the brain?
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Basilar artery, posterior cerebral arteries
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What is a cerebral vascular accident?
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Blood flow that is decreased by thrombus, emboli or hemorrhage (aneurysm). Defect will be functional area of blood distribution
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What is caused by an occlusion of the anterior cerebral artery?
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Unusual for a complete occlusion. May cause motor weakness of contralateral face. Motor and sensory weakness of contralateral leg. Can causes "split brain" - disassociation between the corpus callosum - causes loss of tactile recognition
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What is caused by an occlusion of the middle cerebral artery?
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Gives blood to a huge part of the cerebral hemispheres so this is bad! It is the most common type of occlusion. Can be embolic or hemorrhagic. Causes Contralateral motor loss, contralateral severe sensory loss in face and arm. If it is in the left, can causes expressive aphasia.
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What is caused by an occlusion of the posterior cerebral artery?
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Nerve palsy (CN III), homonymous hemianopsia (loss of half the vision field on same side in both eyes), cortical blindness, alexia (text-blindness)
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What are the cranial nerves?
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12 pairs of nerves from the brain that exit through the cranium to get to the targets
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What is the other name for CN I?
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Olfactory nerve
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Is CN I sensory or motor?
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Sensory
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What is the function of CN I?
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Transmit the sense of smell from the mucosa in the nose
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Where does CN I travel?
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Enters the nose through foramina in cribiform plates
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How would you test the function of CN I?
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Identify smell
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What would result from a lesion to CN I?
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Anosmia, loss of smell. Usually manifests as a loss of taste.
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How might one get a lesion to CN I?
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Fractured cribiform plate (eg struck in face), tumor or abscess of or near frontal lobe if it happens slowly - unilateral or bilateral
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What is another name for CN II?
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Optic nerve
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Is CN II sensory or motor?
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Sensory
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What is the function of CN II?
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Transmits visual info from retina to cortex
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How would you test the function of CN II?
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Visual acuity, visual fields
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What three things can be caused by lesions of CN II?
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Homolateral blindness (one whole side of vision lost), bitemporal hemansopsia (pituitary tumor), homonymous hemanopsia (CVA, TBI)
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What is the other name for CN III?
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Occulomotor nerve
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Is CN III sensory or motor?
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Somatomotor and visceral motor
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What is the somatomotor function of CN III?
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Extra ocular muscles including: superior, medial and inferior rectus mm, inferior oblique m, levator palpabrae m
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How would you test the somatomotor function of CN III?
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Test the function of the extra ocular muscles
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What is the visceral motor function of CN III?
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Parasympathetic nervous system to sphincter muscle of pupil causing puillary constriction
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How would you test the visceral motor function of CN III?
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Accommodation (as we get closer w/ an object closing, should have pupillary constriction), pupillary reaction
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What things might you see in a lesion to CN III?
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Ipsilateral dilated pupil (loss of pupillary reflex), ptosis (eyelid droop), eye turned down and out
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What could cause a lesion to CN III?
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Aneurysm, hematoma, herniation
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What is another name for CN IV?
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Trochlear nerve
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Is CN IV sensory or motor?
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Somatic motor
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What is the function of CN IV?
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Superior oblique muscle
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How would you test the function of CN IV?
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Downward movement and intorsion of the eye
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What would happen in a lesion of CN IV?
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It's small, rarely damaged by itself. Would cause loss of superior oblique - can't turn eye down w/ adduction, eye passively turned in and up. May have diplopia when looking downward
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What could cause a lesion to CN IV?
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TBI, pseudotumor cerebri or meningitis (increased ICP), cavernous sinus mass, orbital trauma
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What is another name for CN V?
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Trigeminal nerve
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Is CN V sensory or motor?
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Sensory AND motor
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What are the three divisions of CN V?
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V1: opthalmic nerve, V2: maxillary nerve, and V3: mandibular nerve
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What is the name for V1 and what is its function?
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Opthalmic Nerve. Sensory from skin of forehead region, cornea, sinuses
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What is the name for V2 and what is its function?
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Maxillary nerve. Sensory from skin over maxillar, teeth, palate
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What is the name for V3 and what is its function?
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Mandibular nerve. Sensation from skin of mandible, teeth, anterior 2/3 tongue. Motor to muscles of mastication (except buccinator)
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How can you test the function of CN V?
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Cotton wisp to cornea, clench teeth, sensation to face
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What might you see in a lesion to CN V?
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Some or all: paralysis of muscles of mastication, devation of mandible toward lesion, loss of sensation of face, loss of corneal reflex
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What could cause a lesion to CN V?
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Trauma, mass, meningitis, aneurysm, MS
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What is trigeminal neuralgia?
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Tic Douloureaux. A disease of unknown etiology that causes irritation to the trigeminal nerve. This results in extreme nerve pain radiating to the face, accompanied by spasm in the trigeminal nerve distribution.
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What is trigeminal herpes zoster?
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Reactivation of varicella virus in trigeminal nerve. Causes a painful vesicular rash of the face in the distribution of one of the three divisions of CN V. Pattern of the rash will determine the particular division involved. Can have permanent corneal scarring, May lead to permanent vision loss.
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What is the tel tale sign of trigeminal herpes zoster?
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Lesion at the tip of the nose.
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What is another name for CN VI?
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Abducent Nerve
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Is CN VI sensory or motor?
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Motor
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What is the function of CN VI?
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Lateral rectus muscles of the eye
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How would you test the function of CN VI?
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Abduction of the eyeball
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What might you see in a lesion of CN VI?
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Loss of ability to abduct the eye, eye may remain medially deviated. Eyebrow droop
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What could cause a lesion of CN VI?
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Cranial base fracture, first CN injured in cavernous sinus mass or spread of infection from sinus
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What is another name for CN VII?
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Facial nerve
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Is CN VII sensory or motor?
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Sensory, motor and visceral motor
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What are the functions of CN VII?
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Motor: controls muscles of facial expression.
Special sensory: Taste from anterior 2/3 tongue Parasympathetic NS: salivary and lacrimal glands |
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How would you test the function of CN VII?
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Show teeth, puff cheeks, wrinkle the brow, close eyes tightly, purse lips
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What could cause a lesion to CN VII?
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Most common injured CN!!! Parotidectomy, temporal bone fracture, distal damage related to Bell's palsy, vascular/ infectious/ genetic/ immunologic causes
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What might you see in a lesion to CN VII?
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Loss depends on region of lesion (UMN, LMN): facial asymmetry, loss of forehead and nasolabial folds, drooping of a corner of mouth, uncontrolled tearing, inability to close eye, lips can't be help tightly together, drooling
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What is another name for CN VIII?
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Vestibulocochlear nerve
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Is CN VIII sensory or motor?
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Special sensory
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What is the function of CN VIII?
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Vestibular sense from inner ear, hearing
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How would you test the function of CN VIII?
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Gross hearing, Weber, Rhinne (tuning fork tests)
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What might you see in a central lesion (both branches) of CN VIII?
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Tinnitus, vertigo (nausea, vomiting), hearing loss, acoustic neroma, trauma
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What is another name for CN IX?
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Glossopharyngeal nerve
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Is CN IX sensory or motor?
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Somatomotor, special sensory, sensory, motor, visceral motor
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What are the functions of CN IX?
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Motor: small muscle of swallowing,
PSNS: Visceral sensory and motor to parotid gland. Sensory: From mucosa of soft palate, pharynx and middle ear, skin of ear. Special sensory: taste from posterior 1/3 of tongue |
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How do you test the function of CN IX?
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Gag reflex (afferent limb)
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What might you see in a lesion of CN IX?
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Decreased taste, loss of gag reflex, swallowing difficulty (dysphagia).
Uncommon to see alone, may see w/ other nerve lesions at jugular foramen (CN IX, X and XI) |
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What is another name for CN X?
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Vagus nerve
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Is CN X sensory or motor?
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Motor, sensory, special sense
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What are the functions of CN X?
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Motor: pharynx (swallow), larynx, palate, upper esophagus.
PSNS: Smooth mm of trachea, bronchi GI and cardiac. Sensory: sensory from all above. Special sensory: taste from epiglottis |
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How would you test the function of CN X?
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Elevation of soft palate "Ah", gag reflex
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What would you see in a lesion of CN X?
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Dysphagia, laryngitis. Uncommon to see alone, may see w/ other nerve lesions (w/in jugular foramen), brainstem lesion. More common to see recurrent laryngeal nerve injury (thyroidectomy)
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What is another name for CN XI?
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Spinal Accessory Nerve
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Is CN XI motor or sensory?
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Somatomotor
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What is the function of CN XI?
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Sternocleidomastoid and trapezius muscles
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How would you test the function of CN XI?
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Resisted movement of sternocleidomastoid and trapezius
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What might you see in a lesion of CN XI?
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Loss of ipsilateral sternocleidomastoid and trapezius function.
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How might one have a lesion of CN XI?
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Very superficial at posterior neck, easily injured in stabbings, node dissections, central line placements in internal jugular, carotid artery surgery
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What is jugular foramen syndrome?
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Could be caused by thrombosis, schwanomas. Damage to CN IX, X, XI
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What might you see in jugular foramen syndrome?
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Dysphagia, dysarthria, hoarseness of voice, ipsilateral trap and scm mm weakness, depressed gag reflex, palatal droop on affected side w/ ipsilateral vocal cord paralysis and loss of taste on posterior 1/3 of tongue, paralysis of uvular, pharynx and larynx
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What is another name for CN XII?
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Hypoglossal nerve
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Is CN XII sensory or motor?
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Motor
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What is the function of CN XII?
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Muscles of tongue
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How would you test the function of CN XII?
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Side-to-side tongue movement
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What might you see in a lesion of CN XII?
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Ipsilateral paralysis of tongue, when tongue protrudes the tip moves toward side of lesion (due to unopposed function of opposite genioglossus muscle).
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How might one have a lesion of CN XII?
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Rarely injured alone. Neck laceration, base of skull fractures.
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What is the most frequently injured motor cranial nerve?
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CN VII Facial nerve
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When does the frontal sinus develop?
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Developed by 7 years of age
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What are 2 characteristics of the frontal sinus?
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Asymmetrical, drains into middle meatus
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What innervates the frontal sinuses?
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CN V1: opthalmic region of trigeminal nerve
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What could cause a distal obstruction of the frontal sinuses?
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polyps, septal deviation, inflammation. Occurs frequently w/ ethmoid sinusitis
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When do the ehtmoid sinuses develop?
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Around 2 years of age
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Where do the ethmoid sinuses drain?
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Into superior and middle meatus. Related to medial wall of orbit.
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What are the ethmoid sinuses innervated by?
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CN V1
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What might you see in ethmoid or frontal sinusitis?
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Infections w/out ability to drain may spread. Might see peri-orbital edema, erythema, orbital cellulitis, blindness (optic nerve sheath), cavernous sinus thrombosis
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When do the sphenoid sinuses develop?
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Around 2 years of age
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Where are the sphenoid sinuses and where do they drain?
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In fragile sphenoid bone. Drain into superior meatus. Close proximity to: optic nerves, pituitary gland, internal carotid arteries, cavernous sinuses
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What innervates the sphenoid sinuses?
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CN V1
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What might you see in sphenoid sinusitis?
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Peri-orbital edema, erythema: orbital cellulitis, blindness: optic nerve sheath, cavernous sinus thrombosis
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What are the maxillary sinuses? When do they develop?
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Largest paranasal sinuses. Developed as embryo - rapid growth to 3 years
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Where do the maxillary sinuses drain?
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Middle meatus - side to side
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What make up the maxillary sinus?
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Roof of sinus is floor of orbit, floor of sinus is alveolar region of maxilla (teeth)
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What innervates the maxillary sinus?
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CN V2
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What is the most common type of paranasalsinusitis?
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Maxillary sinusitis. Ostia (openings) are superior and don't drain w/ head upright. Causes tooth pain.
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What is the nasal cavity?
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2 sides divided by septum. Made up of ethmoid bone, vomer and cartilage.
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What usually causes nose bleeds?
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Picking nose. Septum is well vascularized. If bleed is from posterior portion of nose, bleeds are harder to manage
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What innervates the septum of the nasal cavity?
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CN V
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What are the portions of the nasal cavity?
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Three turbinates (concha) each w/ a meatus (opening).
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What is the function of the turbinates?
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Increase surface area
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What drains into the superior meatus of the nasal cavity?
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Ethmoid sinus
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What drains into the middle meatus of the nasal cavity?
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Frontal, ethmoid and maxillary sinuses
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What drains into the inferior meatus of the nasal cavity?
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Nasolacrimal duct
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What is the pharyngotympanic tube?
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Connects the middle ear to nasopharynx. Balances pressure in tympanic cavity
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What are tympanostomy tubes?
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Tympanostomy tubes may be placed into the tympanic membrane of ppl w/ chronic middle ear infections or fluid. These tubes are meant to equalize the pressure in the middle ear and allow for drainage of fluid from the space.
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What is the respiratory cervical viscera made up of?
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Larynx and trachea
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What are the two functions of the larynx?
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Organ of voice production, keeps airway open
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What are the 5 main components of the laryngeal skeleton?
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Thyroid cartilage (C4), cricothyroid membrane, cricoid cartilage, arytenoid cartilages and epiglottic cartilage
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What is the cricothyroid membrane?
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Band between thyroid and cricoid cartilage. Emergency airways are placed through the cricoid cartilage
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What is the arytenoid cartilage?
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Vocal ligament (cord) attachment
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What are the three components of the internal larynx?
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Vocal ligament, arytenoid cartilage and rima glottidids
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What is the innervation of the internal larynx?
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CN X
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What are the main ways to get a fracture of the laryngeal skeleton?
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Direct blow, sports. For this reason, guards are used in hocky and baseball
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What would a fracture to the laryngeal skeleton cause?
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Dysphagia, dysphonia, dyspnea/ apnea
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What is a tracheostomy/ cricothyroideotomy?
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If a patient is in respiratory distress related to an upper airway obstruction, incision can be made in the trachea inferior to the thyroid and a tracheostomy is placed. Opening is made between rings.
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What structures do you need to avoid when placing a tracheostomy/ cricothyroidotomy?
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Thyroid venous plexus and thyroid ima artery
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In children, what additional structure do you need to avoid when placing a tracheostomy?
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Thymus and brachiocephalic vein
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In an acute airway obstruction, where might an emergency airway be placed?
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At the cricothyroid membrane. This site not generally used for a permanent airway since the tissue (membrane) is less stable than the trachea.
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What is the internal trachea composed of?
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True vocal ligament (fold, cord), false vocal cord (vestibular), arytenoid cartilage, rima glottidis
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What is the function of the true vocal ligament (fold, cord)?
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Source of vocal sounds
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What are the false vocal cords (vestibular)?
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Lateral to true cord - protection of airway
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What is the rima glottidis?
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Space btwn true vocal cords
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What innervates the internal trachea?
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CN X
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What is an endotracheal intubation?
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Flexible tube is put into the trachea and patient is mechanically ventilated
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How is endtracheal intubation placement confirmed?
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Visual tube passing through vocal ligament and equal breathing sounds bilaterally
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What are the two movements of the vocal ligaments and what is the purpose of each movement?
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Abduction for breathing,
Adduction w/ slight separation for phonation |
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What is the trachea?
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Fibrocartilaginous tube. Has incomplete cartilaginous rings and bifurcates at the sternal angle (carina). Right main is vertical and straight while left main is more horizontal
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What is the nasopharynx?
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Nose opens into the nasopharynx via the choanae. This space is posterior to the nose and superior to the soft palate.
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What is the respiratory function of the nasopharynx?
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Warm and moisten the air
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What 3 things are contained within the nasopharynx?
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Pharyngeal opening of the pharyngotympatnic tube (eustacian), pharyngeal tonsil, pharyngeal reccess
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What are the functions of the pharyngeal opening of the pharyngotympanic tube (eustacian)?
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Connects the middle ear to nasopharynx, balances pressure in tympanic cavity (middle ear pressure or fluid accumulation), tubes sometimes placed to vent middle ear and minimize infection and serous otitis media
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What are the pharyngeal tonsils called when they are enlarged?
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adenoids
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What are the pharyngeal tonsils?
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Lymphoid tissue on the roof of the nasopharynx. Superior to the uvula so you can't usually see them. They are often removed in children when they do a tonsilectomy.
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What is the pharyngeal recess?
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Recess behind the osteum of the eustachian tube. Can get inflammation or tumor in this area which can hide for a long time, but eventually put pressure on the eustachian tube
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What is the oropharynx?
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Area posterior to the mouth
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What is the function of the oropharynx?
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Digestive function - swallowing
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What is contained within the oropharynx?
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Soft palate and uvula, tongue (base), lingual tonsils, epiglottis, vallecula, palatine tonsils
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What is the function of the epiglottis?
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Folds down during swallowing to protect the airway
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What is the vallecula?
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A recess related to the epiglottis with potential for trapping a swollowed foreign body or food in ppl with defective swallowing (stroke). Could lead to aspiration pneumonia.
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What is a clinical function of the vallecula?
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Region of placement of laryngoscope for visualization of glottis during intubation
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What are the palatine tonsils?
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"The Tonsils" Region often affected by bacterial infections (eg strep), Removed in a tonsillectomy.
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Where is the laryngopharynx?
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Posterior to the larynx, ends at the esophagus
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What is contained within the laryngopharynx?
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Constrictor muscles, piriform fossa, aryepiglottic folds, and piriform recess
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What is the function of the constrictor muscles in the laryngopharynx?
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Swallowing
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What is the piriform fossa (sinus)?
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Area of the laryngopharynx that is a region of potential foreign body or food pocketing in ppl w/ poor swallowing
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What is the piriform recess?
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On lateral sides of larynx. Bounded medially by aryepiglottic fold and laterally by the thyroid cartilage. potential area for foreign body to lodge
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What is the retropharyngeal space?
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Space continuous inferiorly with the mediastinum, continuous laterally with the parapharyngeal spaces. Can be an issue with infection/ abscess
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What is a retropharyngeal abscess?
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May be caused by a spreading infection from the tonsils. Pts will present w/ sore throat, fever, stiff neck and difficulty swallowing. On phys exam, posterior pharyngeal edema. Main issue with this infection is airway compromise and further spread of infection to mediastinum
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What Is the platysma, what is its action?
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Thin muscle of the neck. Action: skin tension
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What innervates the platysma?
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CN VII
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What are the two triangles of the neck?
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Posterior (aka lateral cervical),
Anterior (aka anterior cervical) |
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What is the posterior triangle?
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Contains occipital triangle and omoclavicular triangle. Borders: Sternocleidomastoid, trapezius, clavical
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What things are contained within the posterior triangle?
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External jugular vein (region for potential short term delivery of meds via central line), CN XI (from edge of SCM to trap), SCM and Trap mm, Phrenic nv overlying anterior scalene.
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What is the floor of the posterior triangle formed by?
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A, M and P scalene mm, levator scapulae, splenius capitis m.
Brachial plexus roots are between anterior and middle scalene mm |
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What is the omohyoid muscle?
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Has two bellies, inferior belly divides posterior triangle into occipital triangle and omoclavicular triangle.
**Many of the structures are found right at the margin of the posterior and anterior triangle and may be better viewed anteriorly. |
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What is the anterior triangle?
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Made up of four smaller triangles (submental, submandibular, carotid and mscular)
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What are the borders of the anterior triangle?
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SCM, Mandible, midline neck
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What are the contents of the submental triangle (which is a part of the anterior triangle)?
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Borders: hyoid, right and left digastric mm.
Contents: submental lymph nodes |
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What are the borders of the submandibular triangle (which is part of the anterior triangle)?
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Inferior mandible and anterior and posterior bellies of digastric mm
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What are the contents of the submandibular triangle (which is part of the anterior triangle)?
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Submandibular gland (wharton's duct internally), submandibular nodes, facial a/v, lingual a, hypoglossal nv on its way to the tongue (move submandibular gland, under posterior belly of digastric m)
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What are the borders of the carotid triangle (which is part of the anterior triangle)?
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Superior belly of omohyoid m, posterior belly of digastric, SCM
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What are the contents of the carotid triangle (which is part of the anterior triangle)?
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CN XI (under SCM) (portions of this nv will be found in posterior and anterior triangle because it's under SCM). Carotid sheath, carotid body, carotid sinus
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What is contained within the carotid sheath?
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Carotid arteries, internal jugular veins, vagus nerve seated between them
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Where is the carotid body?
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Deep to carotid bifurcation
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What innervates the carotid body?
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CN IX and X
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What stimulates the carotid body and what is the result?
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Stimulated by low O2 (to a less extent, high CO2) to increase HR and resp rate
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What is the carotid sinus?
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Dilation of internal carotid artery at the bifurcation (thyroid cartilage)
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What innervates the carotid sinus?
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CN IX and X
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What are baroreceptors?
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In the carotid sinus - respond to pressure changes
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What are the branches of the external carotid artery?
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Superior thyroid, lingual, facial, occipital, maxillary -> middle meningeal
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What are the borders of the muscular triangle?
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Superior belly of omohyoid m, SCM, midline neck
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What are the contents of the muscular triangle?
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Infrahyoid mm, thyroid and parathyroid glands, superior thyroid artery (from external carotid) and inferior thyroid artery (from thyrocervical trunk)
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What is the root of the neck?
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Thoracic inlet, superior mediastinum
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What is the blood supply in the root of the neck off of the aorta?
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Brachiocephalic trunk (right) off of aortic arch, right common carotid, right subclavian, left common carotid, left subclavian --> vertebral a
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What are the other arteries of the root of the neck?
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Transverse cervical artery, dorsal scapular, suprascapular, thyrocervica, vertebral, inferior thyroid
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What are the branches off of the vagus nerves?
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Right recurrent laryngeal inferior to subclavian on right (remember that on the left, the recurrent laryngeal courses LOWER in the mediastinum, but you may see the branch on its way back up the neck to the larynx)
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What are some other structures in the root of the neck?
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Phrenic nn, Cervical sympathetic trunks (2) (would only be visible in retropharyngeal dissection), thoracic duct (coming into junction of the internal jugular and subclavian ven), sometimes a right lymphatic duct, thyroid and parathyroid glands
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What is the thyroid?
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Endocrine gland with two lobes connected by the isthmus. Sometimes a pyramidal lobe centrally. Contains superior and inferior thyroid vessels and lymphatic to deep cervical
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What are the parathyroid glands?
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4 endocrine glands posterior to thyroid gland. Regulate calcium. Contain inferior thyroid vessels. These may inadvertently be removed during a thyroidectomy which would cause a decreased calcium
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What is an enlarged thyroid called? What does it cause?
|
Goiter. May compress esophagus and put traction pressure on recurrent laryngeal nerve causing difficulty swallowing and voice hoarseness. May extend substernal and may compress trachea
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What is a thyroglossal duct cyst?
|
Neck mass or lump. Developed from cells remaining from descent of thyroid gland. Can occur anywhere in path of decent. Pathway that thyroid takes from base of tongue to final position in neck during embryo development may remain open and form cyst. Will fluctuate in size in neck and may be surgically removed.
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What is an ectopic thyroid?
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Failure of thyroid to descend from embryonic tongue region. Uncommon. May look like a thyroglossal duct cyst.
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What is a thyroidectomy and why would you do it?
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Removal of thyroid. Cancer, hyperthyroidism.
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What are some adverse problems to a thyroidectomy?
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Removal of parathyroid glands, damage to left recurrent laryngeal nerves.
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