special senses

Question 1

how does Olfaction occur?

Answer 1

Nose house cillia which bind to the ordorant ( generate a summative receptor potential) GPCR ( NA+/k+ channels open, they connect w mitra cells in the glomerulus region to for CN1.
- olfaction directly involves the limbic system and the amygdala

Question 2

Rods:

Answer 2

densely populated in the outer areas of the retina, they are sensitive to light levels & give use good vision in dim lighting.

Question 3

Cones

Answer 3

most concentrated in the fovea a, best for colour and highest visual acuity.

Question 4

phobia:

Answer 4

very small part of the retina w some cones w/ more rods surrounding.

Question 5

how do photoreceptors work

Answer 5

light enter the eye( lens/cornea)–>image=flipped at the back of the eyeball–> depolarization occurs—-> rods & cones synapes (glomerulus) making CN2—> they change shape–>Cis retinal transitions–> transretinal (activates G protein–> cascade reduces glutamate–> less Na+ channels close ( hyperpolarization)—> less glutamates released off bipolar cells

Question 6

left side of visonary feild can pick up info from____ in addition to the left side( vice/versa)

Answer 6

right side, info crosses over at the optic chiasm

Question 7

what CN control seeing and eye movement?

Answer 7

CN 2,3,6

Question 8

outer ear anatomy

Answer 8

pinna/auricle ( lobe), External acoustic meatus (ear canal), temporal bone

Question 9

middle ear structures:

Answer 9

tympanic membrane, Maleus, Incus, & scapes

Question 10

Inner ear structures:

Answer 10

cochlea, utricle, & saccule, semicircular canals, vestibular apparatus–> CN8–> primary acoustic cortex

Question 11

sclera:

Answer 11

whites of the eyes

Question 12

a tough fibrous coat…

Answer 12

the outer layer of the eye

Question 13

cornea….

Answer 13

a transparent bulg that allows light to pass through it

Question 14

uvea…

Answer 14

middle layer of the eye, dark and vascular layer near the sclera

Question 15

cilliary body….

Answer 15

made up of ciliary muscles that control the shape of the lens to help it focus on near/distant objects

Question 16

iris

Answer 16

circular structures surrounding the pupils

Question 17

lens

Answer 17

transparent biconvex surrounded by an elastic capsule

Question 18

retina

Answer 18

inner walls of the eyes and is pigmeneted ( several layers of neurons)

Question 19

Fovea:

Answer 19

has many cones & provides most acute/colour vision

Question 20

virtuous humor:

Answer 20

stored in the posterior cavity, holds the retina against the choroid & keeps the shape and size

Question 21

aqueous humour

Answer 21

from the anterior cavity continuously secreted by the ciliary process, supplies the eye w nutrients ( lens, cornea; b/c they lack bf)

Question 22

Visual pathway:

Answer 22

Light rays pass through the cornea + are refracted→ aqueous humour & pupil.( curvature of lens = adjusted to refract light)
Light converges on retina( sharper image), rods& cones= stimulated here
Light energy→ electrical stimulus—-> optic nerve—> occipital lobe int he brain
Image is identified and analyzed

Question 23

what are the 6 muscles that control the movement of the eyes?

Answer 23

4 straight ( rectus) muscles
2 angled oblique muscles

Question 24

myopia

Answer 24

nearsightedness, close objects=blurry ( corrected w concave glasses that lenses change when in dim lightning

Question 25

Hyperopia

Answer 25

objects far away are blurry, lens=convex to focus rays o the retina

Question 26

astigmatism

Answer 26

irregular curvature of the lens or cornea

Question 27

presbyopia

Answer 27

inability of the lens to accommodate view while moving closer tot he eyes (most common in elderly)

Question 28

diplopia

Answer 28

double vision

Question 29

eye movement= controlled by what nerves?

Answer 29

CN3,4,6

Question 30

strabismus:

Answer 30

caused by neuro defects or hypertonic muscles/muscle lengths that do not allow the eyes to focus images on the retina, blurred vision - if not fixed brain becomes blined to image produced by that eye Tx: surgery/exercises

Question 31

Nystagmus

Answer 31

involuntary jerky movements of the eyes

Question 32

conjunctivitis

Answer 32

pink eye bacterial/viral/fungal infection, inflammation of the conjunctivia--> can have serous/purulent exudate, itchiness

Question 33

glaucoma

Answer 33

increased Intraoccular pressure 1) trabecular network= unable to drain and pushes against the retinal cells - insidious onset, tunnerl vision, clolourvision= not affected until later

Question 34

narrow angle glaucoma (acute)

Answer 34

cannal of schlemm becomes more narrow stopping th eback flow of fluid - rapid onset, +IOP, discomfort, pupillary response, tx: miotics

Question 35

cataracts

Answer 35

due to a protein build up on the optic lens - blurred vision, easier to see at night time, cuased by diabetes, no eye protection tc: surgery/replacement

Question 36

retinal dettachment

Answer 36

exudative: fluid moves through the capillaries ( separates the retina from the cornea)--> permentant vision loss tanctional: fibrosis occurs between the layers of the retina & cornea spontaneous: when the biterous fluid decreases - spots, blurred vision, painless

Question 37

diabetic retinopathy

Answer 37

blood cells change shapes and clot in the retina--> leaky mature BV--> retinal dettahcment

Question 38

age related macular degeneration

Answer 38

scarring fibriotic tissues int he fovea centralis ( colour vision/acuity) atrophic dry :protiens deposit and damage atrophic wet: large number of leaking blood cells between cornea & retinal layer--> blindness

Question 39

macular degeneration

Answer 39

-acute, painless, occurs when the retina tears away from the underlying choroid due to marked myopia, viterous humor leaks behind loos retina, retinal cells stop working bc they loose nutrient supply

Question 40

conductive hearing loss

Answer 40

impact of cermen on the tympanic membrane ex: qutips

Question 41

sensorineural hearing loss

Answer 41

Cn8 problems, due to toxic meds, loud noises, metanolic disorders

Question 42

Otitis media

Answer 42

infection of the middle ear - makes exudate narrowing ofthe stuachin tube---> scarring permenat damage - pain, hearing loss

Question 43

mineres disease

Answer 43

autoimmune, excess endolymph in the cochlea & vestibular organs & change the function of the hairs in the ears -vertigo, tinnitus, nystagmus

Question 44

utricle and saccule functions....

Answer 44

static equilibrium---> position of head relative to gravity, involved in deccleration

Question 45

dynamic equillibrium organs...

Answer 45

semicircular ducts, balance gead & body= rotated suddenly

Question 46

vestibule apparatus

Answer 46

measures linear acceleration in the verticle ( saccule) and horizontal (utricle) planes