(2) Lab

special senses, reflex, and EMG

lens

protein in eye; focus light into eye

*lens accomodation

retina

layer of photoreceptors

light —>AP

optic nerve

bundle of axons of photoreceptors

NO dendrites jsut axons; no AP

distant lens accomodation

ciliary muscles relaxed

lens relaxed

nearby lens accomodation

ciliary muscles contracts

lens thickens/rounds

right optic nerve lesion

blindness in both sides of right eye

left optic nerve lesion

blindness in both sides of left eye

optic chiasma lesion

blindness in left of left side and right or right side

left optic tract lesion

blindness in right side of both eyes

right optic tract lesion

blindness in left side of both eyes

right visual cortex lesion

blindness in left side of both eyes

neural pathway of vision

optic nerve

optic chiasm

optic tract

visual cortex

conduction deafness

blockage of sound waves from reaching the inner ear

nerve deafness

damage to neurons that send sensory info

rinne test

tests for conduction deafness only

AC > BC = no deafness

AC < BC = deafness

weber test

after CD is ruled out

both ears simultaneously; for nerve deafness

astigmatism

impairment where light doesn’t focus evenly on retina causing blurred vision

caused by irregular shaped cornea or lens that bends light unevenly

near point and aging

lens becomes less flexible; ciliary muscles cannot change shape enough to focus on close objects

optic disc blind spot

no rods or cones to transduce light into neural signal; no AP generated

EMG (mV)

electrical activity associated with skeletal muscle contraction

dynamometry

study of muscle tension/contractile force prod. by muscles

psychological fatigue

decrease in force; decrease in EMG

physiological fatigue

decrease in force; increase/stable in EMG