Anatomy Exam 4- Eye And Ear

Front 1

The Ear

(the vestibulocochlear organ)

Back 1

*a special sensory organ that facilitates both hearing and equilibrium or balance.
*3 regions = external, middle and inner

Front 2

External Ear
used to funnel sound waves and direct these waves toward eardrum and middle ear
Consists of 3 structures...

Back 2

1. auricle
2. external acoustic meatus (external auditory meatus)
3. tympanic membrane (eardrum)

Front 3

Auricle aka pinna

(external ear)

*function and location?

Back 3

*catches sound waves and is the external portion of the ear
*lobe-cartilaginous part on inferior part of auricle (piercings)
*helix- posterior rounded region
*tragus-piece of cartilage that goes over external acoustic meatus

Front 4

External Acoustic (auditory) Meatus

(external ear)

how much is cartilage and how much is bone?
what glands secrete earwax? and what is the name for earwax?

Back 4

*tubular extension of external ear, runs medially toward inner ear
*the canal, about 1 inch, made of both cartilage and bone
*lateral 1/3 tube is cartilage and medial 2/3 is bony
*all covered w/ skin and hair and ceruminous glands that secrete cerumen (earwax)

Front 5

Tympanic Membrane (eardrum)

(external ear)

separates the external ear from the ______ ear.

Back 5

*spans across entire external acoustic meatus
*separates external from middle ear

Front 6

Middle Ear (Tympanic Cavity)

what structures are here?
what is their function?

Back 6

has auditory ossicles that transmit sounds waves into sensory organs, and enable hearing to occur in inner ear

Front 7

Auditory Ossicles (middle ear)
made up of 3 smallest bones in body that connect tympanic membrane to inner ear and transfer sound waves into mechanical motion

what are the 3 bones called?

Back 7

1) malleus
2)incus
3) stapes

Front 8

Malleus

(auditory ossicles - middle ear)

Back 8

hammer-shaped bone that connects to middle of tympanic membrane laterally, and incus medially

Front 9

Incus

(auditory ossicles)

Back 9

anvil-shaped bone that connects medially to the stapes, and laterally to malleus

Front 10

Stapes

(auditory ossicles)

Back 10

shaped like stirrup and attatches to oval window in the bony middle ear cavity

Front 11

when the tympanic membrane vibrates, the motion is transmitted to the...

Back 11

malleus>incus>stapes>oval window (inner ear)

Front 12

The auditory tube (aka eustachian tube) connects the...

Back 12

middle ear to the nasopharynx in order to equalze pressure

Front 13

Clinical Correlate:
Otitis Media

Back 13

*infection of middle ear, most common in children b/c their auditory tube is underdeveloped and horizontal
*often follows upper respiratory infection b/c it can spread through the auditory tube to infect middle ear
*fluid accumulates causing pressure, pain, and possible impaired hearing
*can clear on its on or with andibiotics
*if chronic ear infections occur a myringotomy can be performed- surgery that places small ventilation tube into tympanic membrane to relieve pressure and drain fluid

Front 14

Inner Ear
located in petrous part of temporal lobe called bony labyrinth. within bony labyrinth, there are membranous tubules (membranous labyrinth). Hearing and balance receptors located in membranous labyrinth

Back 14

1) Bony labyrinth
2) Vestibular Complex
3) Cochlea

Front 15

Bony Labyrinth
(inner ear)

Back 15

*space b/w bony and membranous labyrinth filled with perilymph.
*3 divisions = vestibule, semicircular canals, cochlea

Front 16

Vestibular Complex
(inner ear)

Back 16

*formed from vestibule and semicircular canals
*portion of inner ear providing balance by detection of rotation, acceleration and gravity
*receptors are hair cells located in membranous epithelium that detect changes in fluid mvmt caused by head mvmt

Front 17

Cochlea
(inner ear)

Back 17

*consists of bony-coiled tubes that house sensory receptors for hearing
*spiral organ aka. organ of corti = the hearing sensory organ
*hairlike cells in spiral organ respond to change in pressure, creating stimulus of cochlear branch of CNVIII which travels to brain for processing

Front 18

Ear Innervation

Back 18

1) Vestibular Innervation

2) Cochlear Innervation

Front 19

Vestibular Innervation

Back 19

movements of hair cells in vestibular complex detected by sensory neurons of vestibular branch of CNVIII which travls from vestibular complex through the internal acoustic meatus and then to vestibular ganglia. From ganglia, axons target medulla to be relayed into diff. reflexes for eye, head and neck mvmt. Neurns also target cerebellum for coordinated mvmt and to cerebrum for conscious sense of mvmt

Front 20

Cochlear Innervation

Back 20

cochlear branch of CNVIII sense mvmt in tiny hair-like cells in cochlea caused by sound waves. Once mvmt detected, they synapse in cochlear nucleus of medulla. From brainstem, neurons go via thalamus where theyre relayed to auditory cortex of cerebrum, where these impulses are perceived as sound

Front 21

Clinical Correlate:
Hearing Loss

Back 21

1) Conductive Deafness

2) Nerve Deafness

Front 22

Conductive Deafness
(hearing loss)

Back 22

*from middle ear being unable to vibrate and pass sound waves to middle ear.
*Common causes-wax blocking external acoustic meatus, water being trapped in canal and dampening the sound waves

Front 23

Nerve Deafness
(hearing loss)

Back 23

results from inability of vibrations to be detected within cochlea b/c of damage to the cochlea or to CNVIII

Front 24

Bones of the Eye Orbit (7)

Back 24

Maxilla, Lacriminal, Ethmoid, Sphenoid, Frontal, Palatine, Zygomatic

My Lazy Eyes Sees Funny Pink Zebras

Front 25

Eyelids are called...

Back 25

palpebrae

Front 26

Palpebrae
(eyelids)

Back 26

*protective surface for anterior surface of eye
*made of fibrous core (tarsal plate) with skin on anterior side and conjuctiva epithelial cells on post. side
*the epithelial cells secrete a superficial lubricant
*palpebral fissure- separates top and bottom eye lids (upper and lower margins of eye)
*medial canthus is medial connecction of upper and lower eye lids
*lateral canthus is lateral connection
*tarsal glands- seccrete oily substance to lubricate eye lids

Front 27

Eyelashes

Back 27

*hairs attatched to upper and lower margins
*keeps objects from touching eye surface
*a hair root plexus monitors the hairs and mvmt triggers the blinking reflex

Front 28

Eyebrows

Back 28

*rows of thick, short hair extending from superior orbital ridge of frontal bone
*function=keep sweat from anterior eye

Front 29

Lacriminal Apparatus

Back 29

*consists of lacriminal gland, lacriminal sac, and the nasolacrimal duct.
*3 functions=produce, distribute, remove tears

Front 30

What produces tears?

Back 30

la criminal gland is located in the superior lateral eye orbit and is responsible for producing tears

Front 31

What distributes tears?

Back 31

After tears are produced, they flow inferior-medially over the eye and are collected in the lacriminal sac located in the medial canthus

Front 32

How are tears removed?

Back 32

the tears flow to the medial canthus and then into the lacriminal sac. From the sac, the tears flow through the nasolacriminal duct and into the nasal cavity

Front 33

Drainage Pattern of Tears

Back 33

lacriminal duct-->medial canthus-->lacriminal-->lacriminal sac-->nasolacriminal duct-->nasal cavity

Front 34

Anatomy of the Eye
*made up of three layers or tunics and two hallow cavaties
1)The 3 layers consist of..?
2) The two hollow cavaties include...?

Back 34

3 Layers: fibrous tunic, nascular tunic, neural tunic

2 Hollow Cavaties: anterior and posterior cavity

Front 35

Fibrous Tunic (layer of eye)

Back 35

*outermost layer that consists of the sclera and cornea.
*provides mechanical support and an attatchment for mm.

Front 36

Sclera
(Fibrous Tunic-outer most layer of eye)

Back 36

*the white of the eye
*has dense, fibrous connective tissue w/ collagen and elastic fibers over the post. 7/8's of the eye
*thickest part of sclera is post. eye, thinnest is anterior.
*posterior part of is thicker b/c the 6 extrinsic eye mm. attatch here

Front 37

Cornea
(fibrous tunic- outer most layer of eye)

Back 37

*fibrous connective tissue w/ clear squamous epithelium that is continous w/ sclera over the ant. 1/8's of eye.
*is both avascular and transparent which allows vision

Front 38

Vascular Tunic
(layer of the eye)

Back 38

*has alot of blood vessels, lymphatics, and intrinsic eye mm.
*consists of iris, ciliary body, and choroid.
*supplies oxygen and nutrients to tissue in eye, regulates amount of light let into tye eye
*secretes and reabsorbs the aqueous humor
*controls shape of lens

Front 39

Iris
(part of vascular tunic)

Back 39

*can be seen through the transparent cornea and is the color in the eyes.
*has blood vessels, pigment cells, and 2 layers of smooth mm (papillary mm. that control size of pupil and amount of light allowed to enter eye)
*pupil- a hole in the iris that allows light to pass through the eye and project onto the retina

Front 40

constriction of pupil caused by...

Back 40

parasympathetic impulses to pupillary sphincter mm.
*pupillary sphincter mm are circular smooth mm that constric the pupil when they contract
*this reflex lets less light into eye

Front 41

Dialation of pupil caused by...

Back 41

*sympathetic impulses to the pupillary dialator mm.
*these mm radiate from the pupil and cause the pupil to dialate when they contract
*this allows more light into eye

Front 42

Eye Color is determined by...

Back 42

the amount of pigment cells in the iris.
*blue eyes have fewest pigment cells, allowing alot of light to enter eye
*gray and brown eyes have more pigment that lets less light through eye

Front 43

Ciliary Body
(vascular tunic)

Back 43

*tussue composed of ciliary mm thats located at junction of cornea and sclera
*acts to center iris and pupil and support rest of eye
*ciliary mm change the shape of lens to focous light on retina (lens accommodation)
*ciliary body produces fluid that fills anterior cavity called aqueous humor

Front 44

Choroid
(vascular tunic)

Back 44

*layer of vascular tissue b/w the retina and sclera
*has extensive capillary bed, which supplies the retina with oxygen and nutrients

Front 45

*Red Eye flash photography is caused by...

Back 45

flash of a camera reflecting off the choroid layer of eye. the red color produced is actually the light reflecting off blood vessels

Front 46

Neural Tunic
(layer of the eye)

Back 46

*formed by retina which has two different layers (pigmented and neural layer)
*pigmented layer absorbs light brought in via pupil
*neural layers has the neurons that process and integrate visual info
*photoreceptors housed in pigmented layer (rods and cones)

Front 47

vision is the combination of the photoreceptors in the retinal layer

Back 47

1) rods: cannot recgonize color and help with night vision
2) cones: recgonize color and sharpen images. need alot of light to recgonize images, so the presensce of many cones in human retina is why humans cannot see well in the dark compared to other animals

Front 48

Cavaties of the Eye

Back 48

*posterior and anterior cavities
*filled with fluid, helping to keep eyes shape and regidity

Front 49

Anterior Cavity of Eye

Back 49

1) anterior: located b/w lens and cornea, filled w aqueous humor (similar to CSF and is always circulated to help rid waste product in eye)
*epithelial cells on ciliary body produce the aqueous humor
*aqueous humor drains into venous blood system

Front 50

Posterior Cavity of Eye

Back 50

*any area posterior to lens thats filled v/ vitreous humor.
*vitreous humor isn't circulated and helps keep shape of eye

Front 51

Lens
*used to focous visual images on retina wall- specificially photoreceptors of retina
*lens changes shape to focous on images that are far away

Back 51

*lens flattens to see distance
*lens thickens to see near images and is conrolled by parasympathetic nervous system -process called lens acommodation

Front 52

Extrinsic Eye Muscles (6)

Back 52

1. Inferior Rectus
2. Medial Rectus
3. Superior Rectus
4. Lateral Rectus
5. Inferior Oblique
6. Superior Oblique

Front 53

Inferior Rectus
(extrinsic eye mm)

Back 53

*attatchment=inferior surface of sclera (white of eye)
action= depresses eye (moves eye inferiorly)
*innervation= CNIII (oculomotor)

Front 54

Medial Rectus
(extrinsic eye mm)

Back 54

*attatchment= medial surface of sclera
*action= eye adduction (move eye medially)
*innervation= CNIII (oculomotor)

Front 55

Superior Rectus
(extrinsic eye mm)

Back 55

*attatchment=superior surface of sclera
*action= eye elevation
*innervation=CNIII oculomotor

Front 56

Lateral Rectus
(extrinsic eye mm)

Back 56

*attatchment= lateral side of sclera
*action= eye abudction
*innervation=CNVI (abducens)

Front 57

Inferior Oblique
(extrinsic eye mm)

Back 57

*attatchment=inferior-lateral surface of sclera
*action- abduction and eye elevation
*innervation CNIII oculomotor

Front 58

Superior Oblique
(extrinsic eye mm)

Back 58

*attatchment= superior-lateral part of sclera
*action = abduct and depress eye
*innervation- CNIV (trochlear)

Front 59

Mnemonic:
SO4

Back 59

superior oblique innervated by CNIV (trochlear)

Front 60

Mnemonic:
LR6

Back 60

lateral rectus innervated by CNVI (abducens)

Front 61

Mnemonic:
AR3

Back 61

all the rest (of extrinsic mm) innervated by CNIII (oculomotor)

Front 62

Intrinsic Eye Muscles (3)

Back 62

1. Pupillary Sphincter mm (pupil constriction)
2. Pupillary Dialator mm (dialate pupil)
3. Ciliary Muscles (lens accommodation to change lens shape)

Front 63

Pupillary Sphincter Muscle
(intrinsic eye mm)

Back 63

*smooth mm that form circles around pupil
*constrict pupil in response to bright light
*parasympathetic reflex and CNIII carries stimulation to these mm

Front 64

Pupillary Dialator Muscles
(intrinsic eye mm)

Back 64

*smooth muscles that extend radially from pupil
*dialate pupil in response to low light
*sympathetic reflex by CNIII (oculomotor)

Front 65

Ciliary Muscles
(intrinsic eye mm)

Back 65

*used in lens accommodation
*attatch to lens to change its shape
*contraction causes lens to thicken (nearby focus)
*parasympathetic reflex

Front 66

Innervation (visual pathways)

Back 66

a visual image is summation of info from photoreceptors or retina

Front 67

Innervation (visual pathways)

ganglionic axons from retina come together to form...

Back 67

two optic nerves (CNII)

Front 68

Innervation (visual pathways)

the two optic nerves (CNII) relay...

Back 68

sensory info to diencephalon at optic chasim

Front 69

optic chasim

Back 69

point where right and left two optic nerves meet and cross at hypothalamus

Front 70

Innervation (visual pathways)

After crossing optic chasim at hypothalamus...

Back 70

these neurons travel as right and left optic tracts to lateral geniculate nucleux in thalamus (this is where they synapse)

Front 71

Innervation (visual pathways)

Geniculate nucleus relays visual info to...

Back 71

occipital lobe of cerebrum for interpretation

Front 72

Innervation (visual pathways)

info from the left visual field...

Back 72

travels in left optic nerve and then in right optic tract where its interpreted by right side of cerebrum

Front 73

Visual Pathway

Back 73

photoreceptors (rods+cones)--> R/L optic nerves (CNII)--> R/L optic tracts--> lateral geniculate (in thalamus)--> occipital lobe

Front 74

Clinical Correlate:
Glaucoma

Back 74

*caused by increased intraocular pressure b/c of problem circulating and draining aqueous humor
*fluid build up can cause chroid layer to be compressed which doesn't allow vascular delivery of O2 and nutrients
*can cause optic nerve axon displacement
(can lead to retinal cell death, causing blurred or even vision loss

Front 75

Clinical Correlate:
Cataracts

Back 75

*loss of transparency in lens of eye
*happens b/c of aging, can also be caused by diabetes, intraocular infections, and excessive sun exposure
*can be removed by laser surgery, depeding on severity, can be replaced by lens transplant or contact lens

Front 76

Clinical Correlate:
Macular Degeneration

(degeneration of retina)

Back 76

*usually in people >55 yrs and is leading cause of blindness in developed countries
*photoreceptors of eye are lost and pigmented layer is thinned and may also be accompanied by bleeding and scar tissue formation
*eventually- loss of vision (progression can be slowed)
*latest procedure uses lasers to destroy abnormal vessels in eye, leading to bleeding and ultimatlely blindness

Front 77

Hearing and balance receptors located in...

Back 77

membranous labyrinth. (inner ear)