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Flashcards in The Ear + The skin Deck (57)
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1
Q

2 functions of the ear

A

hearing

balance

2
Q

3 parts of a mammalian ear

A

air-filled outer ear
air-filled middle ear
fluid-filled inner ear

3
Q

3 parts of the outer ear

A

pinna
external auditory canal
eardrum

4
Q

pinna is composed of

A

cartilage

5
Q

function of pinna

A

helps to collect and funnel sound waves into the ear

6
Q

external auditory canal

A

lined with hairs and wax-producing cells

7
Q

function of external auditory canal

A

wax traps dirt, microbed etc, and protects ear

8
Q

eardrum

A

a tightly stretched membrane that separates the outer ear from the middle ear

9
Q

function of eardrum

A

transfers sound waves to the middle ear

10
Q

middle ear contains

A

3 bones called the malleus, the incus and the stapes (hammer, anvil and stirrup)

11
Q

function of the bones

A

carry sound waves from the eardrum to the oval window

12
Q

function of oval window

A

transfers sound waves to the inner ear

13
Q

eustachian tube

A

connects middle ear with the pharynx

14
Q

function of eustachian tube

A

keeps air pressure equal on both sides of the eardrum

15
Q

inner ear

A

a coiled tube filled with fluid (lymph)

contains sensory cells

16
Q

inner ear consists of

A

the cochlea

the semi-circular canals, utricle and saccule

17
Q

function of the cochlea

A

hearing - converts sound waves into nerve impulses

18
Q

function of the semi-circular canals, utricle and saccule

A

balance - they detect movement, acceleration and position of head in relation to gravity

19
Q

sound is caused by

A

vibrations in the air

20
Q

first thing that happens to the sound

A

vibrations pass through the outer ear and ear drum to the middle ear

21
Q

when sound waves are in middle ear

A

they pass via the ear bones and oval window the the fluid in the cochlea

22
Q

when sound has reached cochlea

A

movement in the fluid of cochlea stimulates sensory hair cells
sensory cells send electrical impulses to the brain via the auditory nerve
brain interprets these as sound

23
Q

balance

A

semi-circular canals at right angles to each other filled with lymph, receptors in the canals detect movement in 3 planes
movement of head disturbs fluid in canals and stimulates receptors

24
Q

balance receptors stimulated

A

impulses sent to the cerebellum of the brain via the vestibular nerve and muscles are stimulated to contract

25
Q

3 planes

A

forward, backward and circular

26
Q

organs of smell and taste

A

chemoreceptors

27
Q

chemoreceptor

A

stimulated by chemicals dissolved in a watery medium

28
Q

organ of smell

A

olfactory surface in the nose

29
Q

lining of top of inside of nose

A

epithelium

30
Q

epithelium consists of

A

mucus-secreting cells

receptor cells

31
Q

function of mucus secreting cells

A

provides water medium

32
Q

function of receptor cells

A

stimulated by chemicals dissolved in the watery medium (mucus)

33
Q

organ of taste

A

taste buds

34
Q

taste buds

A

consist of groups of sensory cells in the skin of the mouth, tongue and pharynx

35
Q

4 basic tastes in humans

A

sweet
sour
salty
bitter

36
Q

2 layers of skin

A

outer epidermis

inner dermis

37
Q

3 layers of stratified epidermis

A

malpighian layer
granular layer
cornified layer

38
Q

malpighian layer

A

cells divide by mitosis, replacing dead cells rubbed off

contains melanin, pigment that gives colour to skin

39
Q

granular layer

A

a layer of living cells that become filled with grains of keratin as they are moved towards the outside

40
Q

cornified layer

A

thick layer of dead, flattened cells, being rubbed off continuously and replaced from underneath

41
Q

dermis

A

layer of connective tissue

42
Q

what does the dermis contain?

A

protein fibres (collagen), blood and lymph vessels, sensory receptor cells, sweat glands, hair follicles, sebaceous glands and muscles

43
Q

adipose tissue (sub-cutaneous fat)

A

layer of fat storing cells under the dermis

44
Q

3 functions of adipose tissue

A

insulation
energy store
protects muscles

45
Q

5 functions of skin

A
protection
excretion
vitamin production
sense organ 
temperature regulation
46
Q

how does the cornified layer protect

A

the outer layer of dead cells, with keratin, that prevent entry of bacteria, loss of H2O and injury

47
Q

how does melanin protect

A

protects body from uv rays of sun

48
Q

how do sebum and sweat protect

A

make the skin acidic enough to inhibit harmful bacteria

sebum also prevents the skin from drying out and cracking

49
Q

excretion

A

sweat glands produce sweat, which is a watery medium containing small quantities of salt, ammonia and urea

50
Q

vitamin production

A

the action of ultraviolet light on fat in the skin produces vitamin D

51
Q

sense organ

A

the skin contains receptors to detect heat, cold, pressure, touch and pain

52
Q

temperature regulation

A

the body has a constant internal temperature of 37ºC

skin maintains this, with sweat glands, blood vessels and hairs

53
Q

3 ways in which the skin can reduce body temperature in hot conditions

A

sweat glands secrete, heat lost by evaporation
arterioles expand, more blood flows the skin capillaries
hairs lie flat, relaxation of erector muscle - less air trapped

54
Q

2 ways to keep body temperature up by skin

A

hairs stand up to reduce heat loss - warm air trapped

arterioles narrow, less blood to skin capillaries

55
Q

2 additional ways of keeping up body temperature

A

metabolic rate increases (thyroxine secreted)

shivering

56
Q

ectotherms

A

animals whose body temperature varies with the temperature of the environment (cold-blooded)

57
Q

endotherms

A

animals whose body temperature does not vary with the temperature of the environment