HLTS 480- Special Sensory Systems

left

sensation on the right side of the body is delivered to the _________ side of the brain

spinal cord

afferent neurons from pain or temperature receptor cross over when they enter the ________ ________

brainstem

receptors for body movement, limb positions, fine touch discrimination, and pressure

pain, temperature

in the anterolateral system, afferent neurons from _________ or ___________ receptors cross over at the spinal cord

movement, positions, fine, pressure

in the dorsal column system, receptors for body _________________, limb _______________, ________ touch discrimination, and _______________

optical, neural

vision has a...

__________ component which focuses the visual image onto the receptor cells

____________ component which transforms the visual image into a pattern of graded and action potentials

visible light spectrum

the portion of the electromagnetic spectrum that is visible to the human eye

lens

the transparent structure behind the pupil that changes shape to help focus images on the retina

Sclera

white of the eye that blocks light

pupil

the adjustable opening in the center of the eye through which light enters

iris

a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening

retina

location of photoreceptors

- extension of the optic nerve

optic disc

Region at the back of the eye where the optic nerve meets the retina

macula lutea

a yellowish central area of the retina that is rich in cones and that mediates clear detailed vision

- few blood vessels

fovea centralis

tiny pit or depression in the retina that is the region of clearest vision

inverted, backwards

When light enters the eye, the image is ___________ and _____________

Refraction

The bending of a wave as it passes at an angle from one medium to another

ciliary muscles

muscle that pulls on the lens to change the light angles

- controls the opening of the pupil

converges

light _______________ right when it meets the retina in order for the image to be in focus

nearsighted

condition where the eyeball is too long

concave

nearsightedness is corrected by ___________ lenses

farsighted

condition where eyeball is too short

convex

farsightedness is corrected by __________ lenses

cones

the foveal centralis has a high concentration of ________ and a low concentration of _________ ___________

opthalmoscope

instrument used to examine the interior of the eye

hemorrhage

Excessive or profuse bleeding that can be seen as dark spots in an unhealthy eyeball

exudate

fluid, such as pus, that leaks out of an infected wound seen as light spots in an unhealthy eyeball

optic cup

the depression in the center of the optic disc

high

a cup:disc ratio exceeds 0.5 may indicate ________ intraocular pressure

glaucoma

increased intraocular pressure results in damage to the retina and optic nerve with loss of vision

oculomotor nerve

Cranial nerve III

- innervates the skeletal muscles that move the eye

optic chiasm

point at which optic nerve fibers cross in the brain

each

The right and left eye relay information to nerves that travel to ________ occipital lobes

right optic tract

Damage to _________ _________ _________

- loss of the left half of the field of vision of each eye

cross

damage to optic fibers that _________ at the optic chiasm

- loss of outer half of the visual field of each eye

left occipital lobe

damage to _______ ___________ ______

- loss of the right half of the field of vision of each eye

optic tract

leads from optic chiasma to terminate in lateral geniculate body

rods

retinal receptors that detect black, white, and gray

- used for low light vision

less

rods are _________ sensitive than cones

presbyopia

loss of elasticity in the lens with age

- causes need for reading glasses

cataract

clouding of the lens due to the dying of cells

- can replace lens surgically

macular degeneration

breakdown or thinning of the tissues in the macula, resulting in partial or complete loss of central vision

age related macular degeneration

form of macular degeneration occurring in approximately 30% of individuals over the age of 75

pitch

determined by the frequency of sound waves

loudness

determined by the amplitude of soundwaves

tympanic membrane

thin layer of proliferative skin cells separating the outer and middle ear

stapes

last of the three auditory ossicles of the middle ear

- pushes on the oval window

Eustachian tube

A narrow tube between the middle ear and the throat that serves to equalize pressure on both sides of the eardrum

scala vestibuli

leads from oval window to apex of cochlea

scala tympani

extends from apex of cochlea to round window

helicotrema

connection of the scala vestibuli and scala tympani a the far end of the cochlear duct

cochlear duct

a fluid filled cavity within the cochlea that vibrates when sound waves strike it

vestibuli, basilar membrane, tympani

pressure waves travel through the perilymph of the scala ____________, vibrate the ___________ _____________ of the cochlear duct, and exit through the round window via the scala __________

basilar membrane

A structure that runs the length of the cochlea in the inner ear and holds the auditory receptors, called hair cells.

Organ of Corti

Center part of the cochlea, containing hair cells, canals, and membranes that ultimately cause the firing of receptor potentials

high, low

_______ frequency vibrations occur closer to the oval window, _____ frequency vibrations occur closer to the helicotrema

tip links, potassium, calcium, glutamate

in the organ of corti

1. stereocilia are bent toward the tallest member of a bundle

2. _____ ________ pull open mechanically gated gation channels

3. influx of _______________, which depolarizes the membrane

4. opens voltage gated _____________ channels near cell base

5. release ____________________

6. channels close by bending stereocilia in opposite direction

brainstem, thalamus, cortex, temporal

(vestibulo)cochlear nerve fibers synapse with interneurons in the _______________, travel through the ___________, before arriving at the auditory ____________ in the _____________ lobe

cochlear implant

a device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea

healthy tympanic membrane

- very thin

- almost transparent

otitis media

technically inner ear infection on the slides

- inflamed and filled with fluid

india ink

marking tool to determine the growth pattern of skin cells in the tympanic membrane

vision, vestibular, proprioception, touch

since posture integrates _____________, __________ information, ________________, and touch (especially in the feet) it is difficult to find the origin of balance problems

semicircular canals

detect angular rotation of the head

- one canal for each axis

ampulla, cupula

is a structure in the vestibular system, providing the sense of spatial orientation, particularly with rotation

saccule, utricle

Fluid-filled sacs of the vestibular organ that inform the brain about the body's orientation

- location of your head in space

inertia, ampulla, stereocilia

Semicircular canals

1. head moves, and the hair cells of the cilia move with it

2. _____________ causes fluid in the semicircular duct to remain stationary

3. ______________ is pushed against the stationary fluid

4. ______________ bend causing depolarization or hyperpolarization

unstimulated, depolarization, hyperpolarization

semicircular canal hair cells

- ______________ hair cells release a baseline frequency of action potentials

- pushing the hair cells in one direction causes _________________, increasing the frequency

- pushing the hair cells in the other direction causes ____________________, decreasing the frequency

otolith

a calcium particle in the vestibule of the inner ear that adds extra weight to the lymph in th eutricle

vertigo

caused by the otoliths getting lodged

sweet, salty, sour, bitter, umami

5 basic tastes

ligand

the gustatory system is ___________ stimulated (once they're dissolved in water)

glucose

stimulates sweet receptors

sodium

stimulates salty receptors

hydrogen ions

stimulates sour receptors

miscellaneous ligands

stimulated bitter receptors

glutamate

stimulates umami receptors

mucus

in order to smell something, the odorant must be dissolved in _______________

chemical senses

taste and smell