Special Senses

Front 1

Sclera

Back 1

outermost layer of the eye; the white of the eye; extends all around the eye, thickest at posterior portion where optic nerve exits. extra-ocular muscles insert on it.

Front 2

Choroid

Back 2

contains extensive vascular and nutrient network that it delivers to the retina which is the layer internal to it. Sclera covers it externally.

Front 3

retina

Back 3

-neural layer that is innermost of the three layers (sclera choroid retina).
-photoreceptors and corresponding neurons.

Front 4

Cornea

Back 4

continuation of the sclera (connective tissue), but it sits superficially on top of the pupil and lens. Anteriormost layer of the eye.

Front 5

Pupil

Back 5

just deep to the cornea; central opening of the iris; not really a functional structure, just the part that gets smaller and bigger allowing more or less light to enter the eye

Front 6

Iris

Back 6

Layer of smooth muscle and vasculature around the iris; contracts and relaxes to allow more or less light through the pupil that is its central opening. Controled by sympathetic system: parasympathetic - pupillary contraction.
sympathetic - pupillary dilation.

Front 7

Iris

Back 7

Layer of smooth muscle and vasculature around the iris; contracts and relaxes to allow more or less light through the pupil that is its central opening. Controled by sympathetic system: parasympathetic - pupillary contraction.
sympathetic - pupillary dilation.

Front 8

parasympathetic response of pupils

Back 8

pupillary contraction

Front 9

sympathetic response of pupils

Back 9

pupillary dilation

Front 10

lens

Back 10

sits deep to the iris; refracts light rays that hit it; open or closed to light by contraction of the iris, pupil is the opening to the lens.

Front 11

ciliary body

Back 11

attaches to the iris smooth muscle, and suspensory ligaments attach to posterior lens; keep it centered within the iris/pupil, give it convex or concave shape.

Front 12

aqueous space

Back 12

anterior chamber of the eye; region between the cornea (anterior-most layer) and pupil/iris. contains aqueous humor.

Front 13

posterior chamber

Back 13

very small space between bottom of the the lens and the ciliary body (muscles/suspensory ligaments connected to the lens). just underneath muscle layer of iris. contains aqueous humor.

Front 14

conjunctiva

Back 14

connective tissue covering the eyelid inner and outer surface.

Front 15

Bright light response

Back 15

iris contracts to conserve its sanity; a parasympathetic response from c.n. 3 (ciliary ganglion, parasympathetic fibers, etc.)

Front 16

dim light response

Back 16

what if you have to fight/flight? need to see, so iris contracts and pupil dilates; sympathetic response

Front 17

aqueous space

Back 17

consists of anterior(in front of lens) chamber, and a posterior chamber just behind it.

Front 18

vitreous chamber

Back 18

behind the posterior aqueous chamber; the rest of the eyeball.

Front 19

superior colliculus function

Back 19

issues motor commands controlling subconscious eye, head, or neck movements in response to visual stimuli.

Front 20

lacrimal gland

Back 20

produces tears; superior and lateral to the eye itslef (under upper eyelid)

Front 21

nasolacrimal duct

Back 21

in the lacrimal bone, medial orbit; delivers tears to inferior meatus in nasal cavity (on respective side).

Front 22

LR6(SO4)3

Back 22

Lateral Rectus innervated by c.n. 6
superior oblique by c.n. 4
all the rest by c.n. 3

Front 23

7 extraocular muscles

Back 23

levator palpabrae,
superior/inferior oblique,
superior/inferior rectus,
medial/lateral rectus.

Front 24

Collateral optic innervation response

Back 24

When light is directed toward the eye, parasympathetic nerves direct the iris to relax, constricting the pupil; these fibers are alerted by collateral fibers that stimulate before reaching the lateral geniculate nucleus; thus, both pupils contrict

Front 25

auricle

Back 25

the external, visual portion of the ear; flexible, elastic cartilage.

Front 26

external acoustic meatus

Back 26

passageway from external ear to the middle ear's eardrum (tympanic membrane)

Front 27

tympanic membrane

Back 27

aka eardrum; seperates the external ear from the middle ear.

Front 28

middle ear

Back 28

an air-filled space (tympanic cavity)that conatins the ossicles. communicates w/ nasopharynx through eustachian tube.

Front 29

auditory tube

Back 29

aka eustachian; communicates with nasopharynx; equalizes the pressure there with that outside the ear.

Front 30

ossicles

Back 30

MALLEUS STAPES INCUS
-tiny bones within the tympanic cavity or middle ear. rattle when sound hits the tympanic membrane. malleus is against the membrane, incus connects malleus to stapes, stapes is in the oval window.

Front 31

vestibule/semicircular canals

Back 31

contain receptors that provide sense of equilibrium

Front 32

cochlear canal

Back 32

receptors within provide sense of hearing

Front 33

oval window/round window

Back 33

open into the vestibular complex (semicircular canal/cochlea).
stapes sits in the oval window and sends impulse to the cochlea; round window bulges with pressure increase in ear, sensed by the equilibriating vestibule

Front 34

difference between semicircular canals and vestibular utricle/saccule

Back 34

semicircular canals: sense rotation of the head
utricle/saccule: sense gravitational/linear acceleration.

Front 35

ampullae

Back 35

swollen regions within the ducts of the semicircular canals that contain the sensory receptors to rotation of head.

Front 36

medial geniculate nucleus on thalamus

Back 36

recieves auditory impulses

Front 37

process of sound sensation

Back 37

1. pressure wave enter external acoustic meatus
2. Tympanum rattles against ossicles.
3. Ossicles transfer vibration to oval window.
4. Pressure at oval window causes membrane over Round window to bulge.
5. Pressure distorts cochlear duct, stimulates hair cells.
6. Hair sensation stimulates auditory neurons of vestibulocochlear nerve (C.N. 8)

Front 38

intrinsic tongue musculature

Back 38

styloglossus, genioglossus, hyloglossus.
all innervated by hypoglossal nerve XII

Front 39

3 types of taste buds

Back 39

vallate, fungiform, foliate

Front 40

Gustation innervation

Back 40

C.N. V3 - mandibular branch; general sensory from tongue, scratch sensation.

C.N. VII - Facial; taste sensory from anterior 2/3 of tongue.

C.N. IX - Glossopharyngeal; taste sense from posterior 1/3 of tongue.

C.N. X - Vagus nerve; taste sensory.


C.N.