ch 3 Special Senses Flashcards Preview

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Flashcards in ch 3 Special Senses Deck (44):
0

Sensory neurons convey.....

Environment & some internal stimuli to the CNS where it's assimilated

1

Stimulus is a form of..

Energy, receptors change outside energy into nerve action potentials

2

5 senses

Sight
Sound
Touch
Taste
Smell

3

Sensory receptors are........Highly modified dendrites

Taste
Smell
Pressure
Proprioceptor
Audio
Photo
Thermo
Pain

4

Taste

Chemical detection with taste buds

5

Smell

Chemical detection by olfactory cells

6

Pressure

Movement of skin

7

Proprioceptor

Spatial awareness, limbs

8

Audio

Detect sound waves

9

Photo

Detect wavelengths of light

10

Thermo

Detect heat changes

11

Pain

Protect us from environment

12

Sensory adaptation

Occur when receptors become accustom to the stimulus.

(Neuron ceases to fire & receptors become less sensitive)

13

Taste & smell

Work closely together to create the perception of taste

14

Outer layer (eye)

Sclera- supports & protects (internal eye) white part

Cornea- refracts light to pupil (also protective covering)

15

Middle layer

Aqueous humor
Choroid
Iris
Vitreous body
Lens
Pupil

16

Aqueous humor

A liquid
Supplies the cornea w/ nutrients & refracts light

17

Choroid (layer)

Contains pigments that prevent scattering of light in eye
Contains blood vessels that feed the diff structures

18

Iris

Regulates the amount of light entering the eye

19

Vitreous body (humor)

Keeps shape of eye
Permits light transmission to the retina

Irreplaceable!

20

Lens

Focuses the image on the retina

21

Pupil

Functions as a hole in the iris....controls the amount of light that enters as well

22

Inner layer

Retina
Rods
Cones
Fovea centralis
Blind spot

23

Retina

Contains the photoreceptors.....rods and cones

24

Rods

Used for viewing dim (black and white) light there are approx. 125,000,000

25

Cones

Identify color ... Approx 7 million

26

Fovea centralis

Keenest vision.
Most sensitive area of the retina
Only cones

27

Blind spot

Where the optic nerve attaches to the retina
No cones or rods

28

Afterimages

Pos. (after u look at the sun, close ur eyes and still see bright spots)

Neg. (look at bight colours they reverse in color when u look away)

29

Focusing the image

Refraction
Ciliary muscles & suspensory ligaments
Accommodation

30

Ciliary muscles & suspensory ligaments

Control the lens and the amount of light that enters

31

Accommodation

The adjustment of the lens to objects near and far i
-see close: muscles contact, lens round
-see far: muscles relax, lens oval

32

Color vision

Three different types of cones are found in the retina, each sensitive to one of blue, red, green.

Color blind when one type is defective
Red-green is most common

33

Vision defects

Glaucoma -build up of aqueous humour
Cataract -lens/cornea becomes cloudy
Astigmatism
Nearsightedness -eyeball is to long
Farsightedness -eyeball is to short

34

The ear has 2 main functions

Hearing
Equilibrium

35

External ear

Pinna
Auditory canal
Ceruminous gland

36

Pinnacle

(Auricle)
Amplifies sound by funnelling from large to narrow canals

37

Auditory canal

(External auditory meatus)
Carries sounds waves to the tympanic membrane

38

Ceremonious gland

Makes ear wax
-for protection

39

Middle ear

Ossicles (m-anvil I-hammer s-stirrup)
Tympanic membrane - ear drum
Oval window - receives sounds waves de ossicles
Eustachian tube- air filled, equalizes air pressure

40

Inner ear

Vestibule- semicircular canals (keeps equilibrium)
Semicircular canals- fluid filled info w/ equilibrium
Cochlea- tube that converts sound waves to impulses
Cochlear fluid- bathes the organ of corti
Organ of corti- vibrations to impulses

41

Two main components of balance

Static equilibrium
Dynamic equilibrium

42

Static equilibrium

Involves movement on one plane

Saccule, utricle, and otholiths help maintain

43

Dynamic equilibrium

Provide info during movement
Semicircular canals detect direction of movement body adjusts to keep balance

When fluid in semicircular moves continuous it may cause motion sickness