The Ear + The skin

Question 1

2 functions of the ear

Answer 1

hearing

balance

Question 2

3 parts of a mammalian ear

Answer 2

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

Question 3

3 parts of the outer ear

Answer 3

pinna
external auditory canal
eardrum

Question 4

pinna is composed of

Answer 4

cartilage

Question 5

function of pinna

Answer 5

helps to collect and funnel sound waves into the ear

Question 6

external auditory canal

Answer 6

lined with hairs and wax-producing cells

Question 7

function of external auditory canal

Answer 7

wax traps dirt, microbed etc, and protects ear

Question 8

eardrum

Answer 8

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

Question 9

function of eardrum

Answer 9

transfers sound waves to the middle ear

Question 10

middle ear contains

Answer 10

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

Question 11

function of the bones

Answer 11

carry sound waves from the eardrum to the oval window

Question 12

function of oval window

Answer 12

transfers sound waves to the inner ear

Question 13

eustachian tube

Answer 13

connects middle ear with the pharynx

Question 14

function of eustachian tube

Answer 14

keeps air pressure equal on both sides of the eardrum

Question 15

inner ear

Answer 15

a coiled tube filled with fluid (lymph)

contains sensory cells

Question 16

inner ear consists of

Answer 16

the cochlea

the semi-circular canals, utricle and saccule

Question 17

function of the cochlea

Answer 17

hearing - converts sound waves into nerve impulses

Question 18

function of the semi-circular canals, utricle and saccule

Answer 18

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

Question 19

sound is caused by

Answer 19

vibrations in the air

Question 20

first thing that happens to the sound

Answer 20

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

Question 21

when sound waves are in middle ear

Answer 21

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

Question 22

when sound has reached cochlea

Answer 22

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

Question 23

balance

Answer 23

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

Question 24

balance receptors stimulated

Answer 24

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

Question 25

3 planes

Answer 25

forward, backward and circular

Question 26

organs of smell and taste

Answer 26

chemoreceptors

Question 27

chemoreceptor

Answer 27

stimulated by chemicals dissolved in a watery medium

Question 28

organ of smell

Answer 28

olfactory surface in the nose

Question 29

lining of top of inside of nose

Answer 29

epithelium

Question 30

epithelium consists of

Answer 30

mucus-secreting cells | receptor cells

Question 31

function of mucus secreting cells

Answer 31

provides water medium

Question 32

function of receptor cells

Answer 32

stimulated by chemicals dissolved in the watery medium (mucus)

Question 33

organ of taste

Answer 33

taste buds

Question 34

taste buds

Answer 34

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

Question 35

4 basic tastes in humans

Answer 35

sweet sour salty bitter

Question 36

2 layers of skin

Answer 36

outer epidermis | inner dermis

Question 37

3 layers of stratified epidermis

Answer 37

malpighian layer granular layer cornified layer

Question 38

malpighian layer

Answer 38

cells divide by mitosis, replacing dead cells rubbed off | contains melanin, pigment that gives colour to skin

Question 39

granular layer

Answer 39

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

Question 40

cornified layer

Answer 40

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

Question 41

dermis

Answer 41

layer of connective tissue

Question 42

what does the dermis contain?

Answer 42

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

Question 43

adipose tissue (sub-cutaneous fat)

Answer 43

layer of fat storing cells under the dermis

Question 44

3 functions of adipose tissue

Answer 44

insulation energy store protects muscles

Question 45

5 functions of skin

Answer 45

``` protection excretion vitamin production sense organ temperature regulation ```

Question 46

how does the cornified layer protect

Answer 46

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

Question 47

how does melanin protect

Answer 47

protects body from uv rays of sun

Question 48

how do sebum and sweat protect

Answer 48

make the skin acidic enough to inhibit harmful bacteria | sebum also prevents the skin from drying out and cracking

Question 49

excretion

Answer 49

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

Question 50

vitamin production

Answer 50

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

Question 51

sense organ

Answer 51

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

Question 52

temperature regulation

Answer 52

the body has a constant internal temperature of 37ºC | skin maintains this, with sweat glands, blood vessels and hairs

Question 53

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

Answer 53

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

Question 54

2 ways to keep body temperature up by skin

Answer 54

hairs stand up to reduce heat loss - warm air trapped | arterioles narrow, less blood to skin capillaries

Question 55

2 additional ways of keeping up body temperature

Answer 55

metabolic rate increases (thyroxine secreted) | shivering

Question 56

ectotherms

Answer 56

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

Question 57

endotherms

Answer 57

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