A&P Chapter 15 Flashcards Preview

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Flashcards in A&P Chapter 15 Deck (45)
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1
Q

Olfaction

A
  • sense of smell
  • olfactory region
    1. superior region of the nasal cavity
    2. lined with olfactory epithelium
  • olfactory epithelium is constantly replaced
  • olfactory neurons are replaced every 2 months
2
Q

Olfactory epithelium and bulb

A
  • contains 10 million olfactory neurons
  • olfactory neurons are bipolar
    1. axons project to olfactory bulb and synapse with 2nd neuron
    2. olfactory tracts project to cerebral cortex
    3. dendrites extend to olfactory vesicles
3
Q

Neuronal pathways for olfaction

A
  • olfactory relayed to cerebral cortex without thalamus
  • axons enter olfactory bulbs and synapse with mitral cells or tufted cells
  • olfactory tracts: terminate in olfactory cortex or secondary olfactory areas
4
Q

Olfactory cortex

A
  • temporal lobe

- conscious perception of smell

5
Q

Secondary olfactory

A
  • frontal lobe
  • medial olfactory area:visceral and emotional
  • intermediate olfactory area: inhibitory to facilitate rapid adaption
6
Q

Taste(gustatory)

A
  • taste buds: receptors; located in papillae
  • filiform papillae
  • vallate papillae
  • foliate papillae
  • fungiform papillae
7
Q

Histology of taste buds

A
  • oval in shape
  • embedded in tongue and mouth epithelium
  • 3 types of epitheleal cells: taste cells, basal cells, supporting cells.
  • taste cells: replaced constantly, microvilli called taste hairs, opening called taste pore.
8
Q

Function of taste

A
  • substances dissolve in saliva
  • enter the taste pores
  • taste cells depolarize
  • taste cells release neurotransmitters
  • action potential stimulated in sensory neurons
9
Q

Five major tastants

A
  1. Salt: sodium channels
  2. sour: hydrogen gated channels
  3. Sweet: potassium channels
  4. Bitter: calcium release
  5. Unami (glutamate or savory): calcium channel
10
Q

Factors affecting taste perceptions

A
  • temperature: warmth enhances sense of taste; cold inhibits

- structure: specificity not perfect; artificial sweeteners have a higher affinity for receptor binding sites.

11
Q

neuronal pathways for taste

A
  • 3 cranial nerves involved
  • extend from taste buds to medulla oblongata
  • facial nerve(VII): anterior 2/3 of the tongue
  • glossopharyngeal nerve(IX): posterior 1/3 of tongue
  • vagus nerve(X): epiglottis
12
Q

Visual system

A
  • can detect most distant stimuli of all sense
  • eye: eyeball and lens; responds to light
  • accessory structures
  • optic nerve (II)
13
Q

Accessory structures

A
  • eyebrows, eyelids(palpebrae), conjunctiva (thin transparent mucous membrane), lacrimal apparatus( tear production)
14
Q

Lacrimal gland

A

produces tears to moisten, lubricate, and wash. Pass through ducts then to eye

15
Q

Lacrimal canaliculi

A

collect excess tears through openings called puncta

16
Q

Lacrimal sac leads to nasolacrimal duct

A

opens into nasal cavity beneath the inferior nasal conchae

17
Q

nasolacrimal duct

A

opens into nasal cavity

18
Q

extrinsic eye muscles

A
  • responsible for eyeball movement
    1. superior rectus, inferior rectus, medial rectus, lateral rectus, superior oblique, inferior oblique
  • innervated by trochlear(IV), Abducens(VI) and oculomotor(III)
19
Q

Tunics of the eye

A
  • fibrous tunic(sclera)
    1. white layer, gives shape and muscle attachment
    2. light and oxygen enter via cornea
  • vascular tunic(choroid)
    1. middle colored layer
    2. iris regulates amount of light
  • nervous tunic (retina)
    1. neural layer responds to light
    2. contains rods and cones
20
Q

Aqueous humor

A
  • front of eye
  • fills anterior portion
  • maintain occular pressure and eyeball shape
  • provides nutrition
21
Q

Vitreous humor

A
  • back of eye
  • fills posterior portion
  • maintains pressure and shape
  • holds lens and retina in place
22
Q

Lens

A
  • transparent and biconvex
  • anterior surface is cuboidal epithelial cells
  • posterior surface is columnar epithelial cells
  • ligaments suspend lens between posterior and vitreous chambers( ability to stretch
23
Q

Eye functions

A
  • iris allows light to enter the eye
  • light reaches retina is converted to action potential
  • visible light: portion of spectrum that is visible
  • focal point: convergence of light rays
  • eye project clear image on retina
  • adjustment occurs by changing shape of lens
24
Q

Structures and function of retina

A
  • consists of neural and pigmented layer
  • neural layer
    1. photoreceptors, bipolar cells, and ganglionic cells
    2. synapses for adjacent neurons
  • pigmented layer
    1. single kayer of malanin filled cells
    2. isolates photoreceptors and reduces light scattering
25
Q

Rods

A
  • non color vision and reduced light
  • contains rhodopsin( consists of retinal and dopsin)
  • continuously release inhibitory neurotransmitter glutamate
  • glutamate release inhibited by hyperpolarization
26
Q

cones

A

color vision and sharpness

  • contains pigment iodopsin
    1. retinal combined with color- sensitive opsin
    2. each moiety of iodopsin is sensitive to narrow spectrum
  • light hits the retina
  • cones specific for wavelength generate action potential
27
Q

Neuronal pathways for vision

A
  • light enters the retina
  • action potential travel optic nerve
  • optic nerves connect to optic chiasm
  • route of axons called optic tract
  • optic tract can terminate in
    1. lateral geniculate nucleus
    2. superior colliculi
28
Q

Hearing and balance

A
  • divided into 3 parts
  • ## external ear: auricle and external auditory canal,part you can touch and receives sound
29
Q

external ear

A
  • auricle and external auditory canal

- part you can touch and receiver of sound

30
Q

middle ear

A
  • air filled space containing 3 ossicles

- incus, malleus, stapes

31
Q

inner ear

A

houses sensory organs for hearing and balance (eardrum)

32
Q

Auricle

A
  • fleshy visible portion of outer ear

- directs sound waves

33
Q

ceruminious gland

A
  • produces ear wax
34
Q

Tympanic membrane

A
  • thin transparent membrane

- conducts vibration

35
Q

middle ear

A
  • air filled space
  • eustachian tube: opens into pharynx to equalize pressure
  • ear ossicles: malleus, incus, stapes; transmit vibrations to oval window
36
Q

bony labyrinth

A

chambers within the temporal lobe

37
Q

Inner ear contains 3 regions

A
  • cochlea: hearing
  • vestibule: balance
  • semicircular canals:balance
38
Q

Inner ear

A
  • membranous labyrinth: smaller tunnels within bony labyrinth
  • filled wit endolymph and paralymph (fluid)
  • spiral organs contain sensory hair cells
  • hair cells have tip links that open potassium channels
39
Q

external ear

A
  • auricle collects sound waves

- sound waves travel auditory canal to tympanic membrane

40
Q

middle ear

A
  • soundwaves strike tympanic membrane
  • tympanic membrane vibrates
  • ear ossicle vibrate
41
Q

Tensor tympani

A

inserts on malleus; innervated by cranial; nerve V

42
Q

Stapedius

A

inserts on stapes and innervated by cranial nerve VII

43
Q

Attenuation reflex

A

muscles contract during loud noises and prevent damaging vibrations

44
Q

Balance

A
  • static labyrinth: position of head relative to gravity; acceleration and deceleration
  • dynamic labyrinth: evaluating head movement
45
Q

Dynamic labyrinth

A
  • allows direction perception
  • 3 semicircular canals
  • canals expanded into ampulla
  • ampulla contains crista ampullaris
  • crista ampullaris have a gelatinous cupula
  • endolymph moves cupula and causes hair cells to bend