Special sences CH 15 Flashcards Preview

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Flashcards in Special sences CH 15 Deck (66):
1

Palpebae

Eyelids,

2

Conjunctiva

Transperent membrane that lines the eye lids and covers the inner (palpebral conjunctiva) and outer (ocular conjunctiva) surfaces of the eyes.
The fornix is a pocket of the eye where the two conjunctiva become continous

3

Lacrimal apparatus

Consists of:
lacrimal glands and ducts
paired lacrimal canaliculi
lacrimal sac
nasolacrimal duct

4

Lacrimal fluid

Contains lysosomes, mucus and antibodies

5

Extrinsic eye muscles

Control mevement of each eye:

6

Lateral Rectus

Moves eye laterally

7

Medial rectus

moves eye medially

8

Superior rectus

Elevates eye and turns it medially

9

Inferior rectus

Depresses eye and turns it medially

10

Interior oblique

Elevates eye and turns it laterally

11

Superior oblique

Depresses eye and turns it laterally

12

Diplopia

Seeing double because if uncoordinated eye muscles

13

Strabismus

Congentital weakness of the external eye muscles

14

3 layers of the eye

Fibrous layer
Vascular layer
Inner layer

15

Fibrous layer

The outermost coat, composed of dense connective tissue:
Sclera and Cornea
Supports and protects
Serves as attachment sight for the extrinsic eye muscles
Contains structures that assist in focusing

16

Sclera

Posterior portion of fibrous layer, glisining white, opaque. "white of the eye" Protects and shapes the eyeball and provides ancoring point for the eye muscles

17

Cornea

Transparent window, continuous with the sclera.
It allows light to enter the eye.
No blood vessels
Most sensitive portion of the eye

18

Vascular layer (uvea)

Pigmented middle coat of the eye has 3 regions:
Choroid
Ciliary body
Iris

19

Choroid

middle layer the encircles the eye between the retina and the sclera. lBlood vessel rich posterior portion, nourishes the eye and make malanocytes that protect the eye from the sun

20

Ciliary body

Anterior this ring that encircles the lens, controls lens shape and secretes fluid to fill the anterior cavity
Change focus from near to far

21

Iris

Anterior portion of the eye, colored part the contracts and dilates to control the amount of light that enters the pupil
pupillary constrictor and pupillary dilator

22

Inner layer

Innermost layer, retina, nervous layer:
Pigmented layer and Neural layer

23

Pigmented layer of the retina

Single cell think linning, absorb light and act as phagocyles, photoreceptor cell renewal.

24

Neural layer of the retina

Plays direct role in vision. 3 types of neurons: photoreceptors, bipolar cells, and ganglion cells

25

Optic disc

Weak spot in the eye where the optic nerve exits,

26

Rods and Cones

Rods: dim light and peripheral vision receptors
Cones: Color, bright light and HD

27

Internal chambers and fluids

Anterior chamber: Aqueuous humor
Posterior chamber: Vitreous humor

28

Lens

Bioconvex, transparent and changes shap to focas light on the retina.
Image is upside down and backwards
Brain re-orientates image

29

Myopia

Distant objects focus in front of the retina, Eye ball is too long
nearsightedness (can see near)

30

Hyperopia

Focus is beyond the retina
Eye ball is too short
farsightedness (can see far)

31

Astigmatisn

Unequal curvatures in different parts of the eye that lead to blurty images.

32

Phototransduction

Process by which light energy is turned into graded receptor potrntial

33

Rhodopsin

Deap purple pigment of the rods
Changes to opsin in dark
Photoreceptors active in dark
High rate of action potential

34

Striate cortex

Primary visual cortex.

35

Prestriate cortex

Visual association areas

36

Depth preception

Three denominational vision provided my the slightly different images delivered by the two eyes.

37

Chemoreceptors

The receptors for smell and taste, they respond to chemicals in aqueous solution.

38

Olfactory Epithelium

The yellow-tinged patch of pseudostratified epithelium that is the organ of smell

39

Olfactory sensory neurons

Bowling pin shaped receptors in the olfactory epithelium,
Bipolar,
Surrounded by supporting cells that contain yellow brown pigment

40

Olfactory stem cells

Line the base of the epithelium.

41

Olfactory Cilia

Located at the end of each dendrite, increase receptors surface area and are covered by a thin layer of mucus
Largely non-motile

42

Olfactory Transduction

1. Odorant binds to receptor
2. Receptor activates G protein
3. G protein activated adenylate cyclase
4. Adenylate cyclase converts ATP to cAMP
5. cAMP opens a cation channel, allowing Na+ and Ca+ influx causing depolarization.

43

Olfactory pathway

Axons of olfactory sensory neurons form>
Olfactory nerve, with synapse in>
Olfactory bulbs which are the distal end of the>
Olfactory tract, where>
Mitral cells (second-order sensory neurons) synapse in>
Glomeruli

44

Papillae

Peg like projections of the tongue mucosa that make the tongue slightly abrasive.

45

Fungiform papillae

Mushroom shaped papillae scattered over the tongue. Taste buds are located mainly on the tops and in the side walls of the foliate papillae

46

Vallate papillae

Largest and least numerous papillae
7-12 of them form an inverted V at the back of the tongue.

47

Taste bud

Each flask shaped bud consists of 50- 100 epithelial cells of 2 types:
Gustatory
Basal

48

Gustatory epithelial cells

The taste cells, contain gustatory hairs

49

Gustatory hairs

Sensitive portion.
long microvilli called gustatory hairs that extend through a taste poor to the surface of the epithelium where they are bathed in saliva.

50

Basal epithelium

Stem cells that divide into new gustatory cells

51

5 tastes sensationss

Sweet
Sour
Salty
Bitter
Umami

52

Activation of taste receptors

Salty: Na+ influx directly depolarizes
Sour: H+ opens cation channels
Sweet, Salty and Umami: common mechanisms in different cells. Couples with G protein gustducin

53

Gustatory pathway (Cranial nerves)

Facial nerve: from anterior tho thirds of the tongue
Glossopharyngeal: serves posterior tongue and pharynx.
Vagus nerve: epiglottis and lower pharynx

54

Influence on other sences

80% of taste is smell. Temperature and texture of food enhances taste as well.

55

3 major ear regions

External ear
Middle ear
Inner ear

56

External ear structures

Auricle: funnels sound waves into the ear
Auditory canal: short curved tube that extends from the auricle to the eardrum
Tympanic memrane: flattened translucent cone that separates outer and middle ear.
sound waves make eardrum vibrate

57

Middle ear structures

or tympanic cavity: flanked laterally by the tympanic membrane and medially by a bony wall with the oval and round windows. Houses auditory ossicles

58

Auditory ossicles

Malleus : hammer
Incus : anvil
Stapes :stirrup

59

Inner ear structures

Bony labyrinth
Membranous labyrinth
Vestibule
Semicircular canals
Cochlea

60

Bony labyrinth

Canals worming through the bone, filled with perilymph fluid

61

Membranous labyrinth

Continuous membranous sacs and ducts with in the bony labyrinth. Filled with endolymph fluid.

62

Vestibule

Central egg shaped cavity of the bony labyrinth, two sacs: saccule and utricle. Houses equillibrim receptors called maculae.

63

Semicircular canls

Anterior lateral and posterior canals, responds to angular rotational movement of the head.
semicircular ducts inside with ampulla housing equilibrium receptors called crista ampullaris.

64

Cochlea

Snail shaped and houses the cochlear duct that contains the receptor organ for hearing: the spiral organ or organ of Corti.

65

3 cochlear chambers (or scalae)

Scala vestibuli
Scala media
Scala tympani

66

Pathway for sound travel

1. sound waves vibrate eardrum
2. Auditory ossicles vibrate and amplify
3. Pressure waves from the stapes push on oval window and move into the fluid in the scala vestibule
4. Sounds in hearing range go through cochlea duct vibrate basilar membrane and deflecting hairs on inner hair cells.