Practical One

olfaction

sense of smell

gustation

sense of taste

substances dissolved in saliva

gustation

substances dissolved in fluids of nasal membranes

olfaction

taste sensations

sweet, sour, salty, bitter, umami

what causes sweet taste

sugar

what causes sour taste

acids

what causes salty taste

inorganic salts

what causes bitter taste

alcaloides and spoiled foods

what causes umami taste

aspartic acid and glutamic acid

CN VII

facial nerve:

taste buds anterior 2/3 of tongue

CN IX

glossopharyngeal nerve:

taste buds posterior 1/3 of tongue

CN X

vagus nerve:

taste buds of palate, pharynx and epiglottis

papillae

filiform, fungiform, vallate, foliate

vallate

posterior - over 100 taste buds

fungiform

anterior - 5-10 taste buds

filiform

anterior - no taste buds (holds food in place) → spikey, think of cats

foliate

sides of tongue

adaptation of olfaction

decrease in sensitivity to a stimulus (odor) over time

extrinsic eye mucles

lateral rectus

medial rectus

superior rectus

inferior rectus

inferior oblique

superior oblique

lateral rectus innervation

CN VI - abducens

medial rectus innervation

CN III - oculomotor

superior rectus innervation

CN III - oculomotor

inferior rectus innervation

CN III - oculomotor

inferior oblique innervation

CN III - oculomotor

superior oblique innervation

CN IV - trochlear

lateral rectus direction

laterally

medial rectus direction

medially

superior rectus direction

superiorly

inferior rectus direction

inferiorly

inferior oblique direction

superiorly and laterally

superior oblique direction

inferiorly and laterally

conjunctivitis

inflammation of conjunctiva (AKA pink eye)

tunics / layers of eyes

fibrous tunic, vascular tunic, retina

fibrous tunic: outer layer

sclera + cornea

sclera

white part of eye, dense collagenous CT with blood vessels and nerves

attachment point for extrinsic eye muscles

cornea

transparent region of modified sclera, allows light to penetrate

vascular tunic: middle layer

iris + ciliary body + choroid

iris

adjustable diaphragm that controls diameter of pupil

• 2 pigmented layer

ciliary body

muscular ring → secretes aqueous humor

choroid

highly vascularized. dark pigment behind retina

retina: inner layer

pigmented layer + neural layer

astigmatism

inability to simultaneously focus light rays that enter the eye on different planes

hyperopia

farsightedness - a condition where the eyeball is too short

myopia

nearsightedness - a condition where the eyeball is too long

presbyopia

reduced ability to accommodate for near vision with age