E4 Ch. 16 Flashcards Preview

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Flashcards in E4 Ch. 16 Deck (80):
1

what are the special senses

taste, smell, sight, hearing, and balance

2

define touch

a large group of general senses

3

describe special sensory receptors

localized (confined to head region), distinct receptor cells, special receptor cells

4

describe special receptor cells

neuron like epithelial cells or small peripheral neurons, transfer sensory info to other neurons in afferent pathways

5

another name for taste

gustation

6

another name for smell

olfaction

7

what are the receptors for taste and smell classified as

chemoreceptors

8

describe chemoreceptors

respond to chemicals; food dissolved in saliva, airborne chemicals that dissolve in fluids of the nasal mucosa

9

where do taste receptors occur

in taste buds; most found on surface of tongue, located w/in tongue papillae

10

name the 2 types of papillae (with taste buds)

fungiform and vallate papillae

11

what are the 2 major cell types found in taste buds

gustatory epithelial cells (supporting cells) and basal epithelial cells (gustatory cells)

12

how often are taste buds replaced

every 7-10 days

13

name the 5 basic qualities of taste

sweet, sour, salty, bitter, and umami

14

what chemical is "umami" elicited by

glutamate

15

what part of the brain does taste info. reach and though which nerves

the cerebral cortex; facial (VII) and glossopharyngeal (IX) nerves, some though vagus nerve (X)

16

describe the gustatory pathway

sensory neurons synapse in medulla located in solitary nucleus, impulses transmitted to thalamus to gustatory area of cerebral cortex in insula

17

olfactory epithelium is pseudostratified columnar and contains what 3 main cell types

olfactory sensory neurons, supporting epithelial cells, and olfactory stem cells

18

where are the cell bodies of olfactory sensory neurons located

in olfactory epithelium; have apical dendrite that projects to epithelial surface

19

what acts as a receptive structure for smell

olfactory cilia; mucus captures and dissolves oder molecules

20

describe filaments of the olfactory nerve

bundled axons of olfactory sensory neurons

21

what structures do the filaments of the olfactory nerve penetrate and where does it synapse with

penetrate cribriform plate of ethmoid bone to enter the olfactory bulbs and synapse w/ mitral cells

22

function of mitral cells

transmit impulses along olfactory tract to the limbic system and the piriform lobe of the cerebral cortex

23

anosmia

absence of the sense of smell, due to injury, colds, allergies, or zinc deficiency

24

uncinate fits

distortion of smells or olfactory hallucinations, often results from irritation of olfactory pathways after brain surgery or head trauma

25

olfactory epithelium is derived from what

olfactory placodes

26

how are taste buds developed

upon stimulation by gustatory nerves

27

list the accessory structures of the eye

eyebrows, eyelids, lacrimal caruncle, tarsal plates, tarsal glands, and conjunctiva

28

describe the conjunctiva and list its parts

transparent mucous membrane; palpebral conjunctiva, bulbar conjunctiva, and conjunctival sac

29

function of the lacrimal apparatus

keeps surface of eye moist

30

lacrimal gland

produces lacrimal fluid

31

lacrimal sac

fluid empties into nasal cavity

32

how many muscles control eye movement and where do they originate/insert

6; originate in walls of orbit, insert on outer surface of eyeball

33

what is the origin of the 4 rectus muscles of the eye

anular ring

34

list the 6 extrinsic eye muscles

lateral, medial, superior, inferior rectus, superior, inferior oblique

35

function of the sclera

provides shape and an anchor for eye muscles

36

function of limbus

junction b/t sclera and cornea

37

purpose of the scleral venous sinus

allows aqueous humor to drain

38

purpose of the choroid

vascular, darkly pigmented membrane that prevents scattering of light rays w/in the eye

39

what type of muscle is the iris composed of

smooth muscle

40

what is the pupillary light reflex

protective response of pupil constriction when a bright light is flashed in the eye

41

what two laters compose the retina

pigmented layer and neural layer

42

describe the pigmented layer of the retina

single layer of melanocytes

43

describe he neural layer of the retina and the 3 types of neurons found there

sheet of nervous tissue; photoreceptor, bipolar, and ganglion cells

44

describe the 2 main types of photoreceptors

rod cells- more sensitive to light; allows vision in dim light, black and white

cone cells- operate bes in bright light; enable high-acuity, color vision

45

ora serrata

neural layer ends at posterior margin of the ciliary body, pigmented layer covers ciliary body and posterior surface of the iris

46

what type of photoreceptors are found in the macula lutea

mostly cones

47

what type of photoreceptors are found in the fovea centralis

only cones; region of highest visual acuity

48

what two sources supply blood to the retina

outer third of retina receives from capillaries in the choroid

inner two-thirds of retina receives from the central artery and vein of the retina

49

function of the vitreous humor

transmits light, support posterior surface of lens, helps maintain intraocular pressure

50

function of aqueous humor

formed as a blood filtrate; supplies nutrients to lens and cornea

51

what structures make up the refractory media

lens, cornea, and humors

52

what is the refractory media

light bending structures

53

where does visual information travel to

mostly in cerebral cortex, other pathways include nuclei in the midbrain and diencephalon

54

describe the visual pathway to the cerebral cortex

light, beings at retina, activates photoreceptors which signal bipolar cells which signal ganglion cells then axons of ganglion cells exit eye as the optic nerve, axons to lateral geniculate nucleus of thalamus, synapse w/ thalamic neurons, fibers of optic radiation reach primary visual cortex

55

retinopathy of prematurity

blood vessels grow w/in eyes of premature infants, vessels have weak walls causing hemorrhaging and blindness

56

trachoma

contagious infection of the conjunctiva

57

what are the 3 main regions of the ear and what are their general functions

external- hearing
middle- hearing
internal- hearing and equilibrium

58

name the structures that make up the external ear

auricle, external acoustic meatus, and tympanic membrane

59

function of auricle

helps direct sounds

60

what components does the external acoustic meatus contain

hairs, sebaceous glands, and ceruminous glands

61

function of tympanic membrane

forms boundary b/t external and middle ear

62

what 3 parts comprise the bony labyrinth (internal ear)

semicircular canals, vestibule, and cochlea

63

what is the membranous labyrinth of the internal ear

series of membrane-walled sacs and ducts that fit w/in the bony labyrinth

64

what 3 parts comprise the membranous labyrinth of the internal ear

semicircular ducs, utricle and saccule, and cochlear duct

65

what type of fluid is found w/in the membranous labyrinth

endolymph

66

what type of fluid is found w/in the bony labyrinth

perilymph; continous w/ CSF

67

what area of the cochlea contains receptors for hearing

the cochlear duct (scala media)

68

spiral organ

receptor epithelium for hearing

69

function of inner hair cells

receptors that transmit vibrations of the basilar membrane

70

function of the outer hair cells

actively tune the cochlea and amplify the signal

71

function of the macula of the vestibule

monitor position of head when head is still

72

what planes do the 3 semicircular canals lie in

anterior and posterior semicircular canals= vertical plane @ right angles

lateral semicircular canal=horizontal plane

73

where is the crista ampullaris located and its function

housed in membranous ampulla; contains receptor cells of rotational acceleration, epithelium contains supporting cells and receptor hair cells

74

describe the steps of the auditory pathway

impulses from cochlear nerve to cochlear nuclei in medulla, neurons project to superior olivary nuclei, axons ascend in lateral lemniscus to inferior colliculus, projects to medial geniculate nucleus of thalamus to primary auditory cortex

75

describe the equilibrium pathway

transmits info on position and movement of head, most info goes to lower brain centers (reflex centers)

76

motion sickness

carsickness, seasickness, popular theory for a cause- mismatch of sensory inputs

77

Meniere's syndrome

equilibrium is greatly disturbed, excessive amounts of endolymph in membranous labyrinth

78

conduction deafness

sound vibrations cannot be conducted to the inner ear, ruptured tympanic membrane, otitis media, otosclerosis

79

sensorineural deafness

results from damage to any part of the auditory pathway

80

presbycusis

gradual loss of hearing w/ age