Sensory Physiology 1

Front 1

Types of receptors?

8

Back 1

Chemoreceptors
photoreceptors
thermorecepetors
mechanoreceptors
nociceptors
special senses
propioceptors
cutaneous

Front 2

sense chemical stimuli in environment or blood.

examples

Back 2

Chemoreceptors

taste buds, olfactory epithelium

Front 3

Rods and cones in the retina of the eye

Back 3

Photoreceptors

Front 4

respond to hot and cold

Back 4

Thermoreceptors

Front 5

stimulated by mechanical deformation of the receptor cell membrane

Back 5

Mechanoreceptors

touch and pressure in the skin, hair cells within the ear

Front 6

Pain receptors
firing rate increases with increased stimulus.

Back 6

Nociceptors

have a high threshold (need intense stimulus)

Front 7

receptors that mediate sight, hearing, and equilibrium

Back 7

Special senses

Front 8

joint receptors
sense of body position
fine control of movements

Back 8

Propioceptors

Front 9

touch and pressure receptors
heat and cold
pain

Back 9

Cutaneous (skin) receptors

Front 10

Sensory Adaptation

2 types

Back 10

receptors vary in duration of firing response to a constant stimulus
tonic
phasic

Front 11

tonic receptors
slow adapting

Back 11

continue to fire as long as the stimulus is maintained.
monitor presence and intensity of stimulus

Front 12

Phasic receptors
fast adapting

Back 12

burst of activity then quickly decrease firing rate if stimulus is maintained.
forget a watch is on your hand.
odor,touch,temp

Front 13

graded changes (usually depolarizations) in the membrane potential of the dendritic endings of sensory neurons

Back 13

Generator (receptor) potentials

magnitude directly proportional to strength of stimulus

Front 14

70% of all sensory receptors are located in the ____

Back 14

eye

Front 15

eyebrows, eyelids, conjunctiva, lacrimal apparatus, and extrinsic eye muscles are _____structures

Back 15

Accessory

Front 16

internal cavity of eye is filled with___

Back 16

a fluid called humors

Front 17

3 tunics (coats/layers) making up the wall in the eye

Back 17

fibrous
vascular
sensory

Front 18

separates internal eye into anterior and posterior segments

Back 18

lens
allows precise focusing of light onto retina

Front 19

chamber between cornea and the iris

Back 19

Anterior
front of the eye

Front 20

chamber between iris and lens

Back 20

posterior

Front 21

filled with aqueous humor --> drains via canal of schlemm
supports,nourishes, removes waste

Back 21

Anterior segment

Front 22

filled with clear gel (vitreous humor)
transmits light
contributes to intraocular pressur

Back 22

Posterior segment

Front 23

forms the outermost coat of eye
protects and anchors extrinsic muscles

Back 23

Fibrous tunic

composed of
opaque sclera (posterior)
clear cornea (anteriorly)

Front 24

the ____ lets light enter the eye

Back 24

cornea

Front 25

Vascular tunic (Uvea)

what 3 regions?

Back 25

Choroid region
ciliary body
iris

Front 26

A thickened ring of tissue surrounding the lens
smooth muscle bundles
anchors suspensory ligament to hold lens

Back 26

Ciliary body

Front 27

dark brown membrane surrounding the eye. forms posterior portion of vascular tunic
supplies blood to all eye tunics

Back 27

Choroid region

Front 28

colored part of the eye
contains the pupil

Back 28

Iris

Front 29

Pupil

Back 29

central opening of the iris.
regulates amount of light entering.
close/bright=constriction
far/dim= dilation

Front 30

sensory (internal) tunic

what are the 2 layers?

Back 30

Retina

Pigmented layer
Neural layer

Front 31

cones in retina absorb different wavelengths
Blue
Green
Red

Back 31

420nm
520nm
560nm

Front 32

focusing for distant vision

Back 32

ciliary muscle relaxed
suspensory ligament tight
THIN lens

Front 33

Focusing for close vision

Back 33

ciliary contraction
suspensory relaxed
pupil constricts
convergence(medial rotation toward object)

Front 34

normal eye with light focused properly

Back 34

emmetropic eye

Front 35

focal point is in front of the retina

fixed with concave lens )(

Back 35

myopic eye (nearsighted)

Front 36

focal point is behind the retina

fixed with convex lens ()

Back 36

hyperopic eye (farsighted)

Front 37

Ganglion cell axons run along the ___ of the retina

Back 37

inner surface

leave eye as the optic nerve

Front 38

the site where the optic nerve leaves the eye
blindspot

Back 38

the optic disk

Front 39

photoreception

Back 39

process by which the eye detects light energy

Front 40

Photoreceptors

Back 40

rods and cones
contain photopigments
change shape as they absorb light

Front 41

functional characteristics of Rods

Back 41

sensitive to dim light, best for night vision.
inputs received as gray tones
MANY rods feed to single ganglion
fuzzy, indistinct images

Front 42

Functional characteristics of Cones

Back 42

need bright light for activation
vividly colored view
1 cone --> single ganglion
detain, high res

Front 43

Retinal is a _____molecule,
combines with ___ to form visual pigments

Back 43

light absorbing
opsins (proteins)

Front 44

2 isomers of retinal

Back 44

11-cis
all-trans

Front 45

visual pigments of rods and cones

Back 45

rhodopsin (opsin + 11-cis retinal)

Front 46

excitation of rods and cones

light phase
dark phase

Back 46

light- rhodopsin breaks down into all-trans retinal + opsin (bleaching)

Dark- all-trans converts to 11-cis
regenerate rhodopsin

Front 47

3 types of cones
3 colors?
how are intermediate colors made?

Back 47

Blue
Green
Red
Activation of multiple cones

Front 48

process of phototransduction?

Back 48

light splits rhodopsin to all-trans --> releasing activated opsin.
opsin activates G protein transucin --> catalyzes activation of PDE --> hydrolyzes cGMP to GMP and releases it from Na channels.
Na closes --> hyperpolarization

Front 49

going from darkness to light, ____ function is lost. switching to the ___ system --> visual acuity gained

Light to dark?

Back 49

Rod

Cone

reverse.

Front 50

Trichromatic color vision

Back 50

S cone - blue
M cone - green
L cone - red

Front 51

Receptive fields on ganglion cells

Back 51

On-center fields

off-center fields

Front 52

field stimulated by light hitting the center
inhibited by light hitting periphery

Back 52

On-center

Front 53

field stimulated by light hitting periphery

Back 53

Off-center

Front 54

geniculostriate system

Back 54

visual perception
70-80%

Front 55

Tectal system

Back 55

eye/body movements
20-30%

Front 56

area 17

Back 56

striate cortex

Front 57

areas 18-19

Back 57

vis assoc. areas

Front 58

thalamic processing

Back 58

lateral geniculate nuclei,
relay info on movement
depth perception
emphasize visual inputs
sharpen the contrast info from retina

Front 59

Cortical processing

Back 59

striate cortex processes- dark/bright and contrast info
prestriate- form, color, movement
Visual info --> anteriorly to the
temporal lobe- i.d. objects
parietal cortex, postcentral gyrus- spatial location

Front 60

muscles and functions of the eyebrows

Back 60

shading the eye, deter sweat from eye

orbicularis muscle- depress eyebrows
corrugator- move medially

Front 61

function and parts of the eyelids (palpebrae)

Back 61

protect the eye anteriorly

Lacrimal caruncle- glands secrete white, oily secretion (sandman)
Levator palpebrae superioris- mobility of upper eyelid

Front 62

initiate reflex blinking

Back 62

eyelashes

Front 63

lubricating glands associated with eyelids

Back 63

sebaceous
ciliary glands

Front 64

transparent membrane that
lines the eyelids
covers whites of eyes
lubricates and protects

Back 64

Conjunctiva

Front 65

Lacrimal glands secreate ____

Back 65

tears

contain mucus, antibodies, lysozyme
drain into nasolacrimal duct

Front 66

Extrinsic eye muscles
6____
4____
2____

Back 66

straplike muscles- follow moving objects and maintain shape of eye
Rectus- originate from annular ring
Oblique- move eye in the vertical plane