Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

biology > homeostasis and hormones > Flashcards

homeostasis and hormones Flashcards

1
Q

define hormones

A

chemical messengers used in the body that are carried in the plasma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are glands

A

organs that secrete or release substances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

endocrine glands:

A
  • no ducts
  • release hormones directly into blood stream
  • e.g. pituitary and thyroid gland
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

exocrine glands:

A
  • have ducts
  • hormones secreted into blood stream via ducts
  • e.g. salivary glands, tear glands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

where is FSH produced

A

pituitary gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

role of FSH

A

stimulates egg maturation and oestrogen secretion in females
stimulates sperm production in males

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

where is LH produced

A

pituitary gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

role of FSH

A

stimulates egg release (ovulation) in females
stimulates testosterone production in males

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

where is ADH produced

A

pituitary gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

role of ADH

A

controls water content of blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

where is thyroxine produced

A

thyroid gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

role of thyroxine

A

controls metabolic waste

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

where is insulin produced

A

pancreas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

role of insulin

A

lowers blood glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

where is glucagon produced

A

pancreas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

role of glucagon

A

raises blood glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

where is adrenaline produced

A

adrenal gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

role of adrenaline

A

prepares body for physical activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

where is oestrogen produced

A

ovaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

role of oestrogen

A

controls development of female secondary sexual characteristics
stimulates thickening of uterus lining

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

where is progesterone produced

A

ovaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

role of progesterone

A

regulates menstrual cycle
maintains uterus lining

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

where is testosterone produced

A

testes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

role of testosterone

A

controls development of male secondary sexual characteristics
stimulates sperm development

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

how do messages move around the body in the nervous system

A

impulses are transmitted through nerve cells (although chemical at synapse)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

how do messages move around the body in the endocrine system

A

hormones are transported in the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

speed of impulse travel and time taken for effect to happen in nervous system

A

impulses travel fast and have an ‘instant effect’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

speed of hormones and time taken for effect to happen in endocrine system

A

travel more slowly and generally take longer to act

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

length of response time in nervous system

A

response is usually short-lived

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

length of response time in endocrine system

A

response is usually longer lasting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

is the effect localised or widespread in the nervous system

A

impulses act on individual cells such as muscle fibres, so have a very localised effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

is the effect localised or widespread in the endocrine system

A

can have a widespread effect on different organs (although they only act on particular tissues and organs of they have the correct receptors)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

when do adrenal glands secrete adrenaline

A

when you are excited/scared/angry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what does adrenaline do

A

prepares the body for action / physical activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

effect of adrenaline on the heart

A

heart rate increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

why does the heart rate increase when adrenaline is released

A

pumps MORE blood to transport MORE oxygen and glucose to respiring cells in the muscles so MORE aerobic respiration can occur, releasing MORE energy, so there can be MORE muscle contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

effect of adrenaline on the lungs

A

breathing rate increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

why does the breathing rate increase when adrenaline is released

A

MORE oxygen for more aerobic respiration, which releases MORE energy, leading to MORE muscle contractions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

effect of adrenaline on the arterioles in muscles

A

arterioles dilate to increase blood flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

why do arterioles in muscles dilate when adrenaline is released

A

increased blood flow -> MORE oxygen and glucose transported to respiring cells in muscles -> MORE aerobic respiration -> MORE energy produced -> MORE muscle contractions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

effect of adrenaline on arterioles in digestive system

A

constrict to decrease blood flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

why do arterioles in digestive system constrict when adrenaline is released

A

constrict to decrease blood flow as there is no need for digestion of food; oxygen and glucose used in respiration in muscles cells instead

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

effect of adrenaline on the liver

A

releases glucagon to convert glycogen into glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

why does the liver release glucagon when adrenaline is released

A

glucagon converts glycogen into glucose -> glucose gets released into bloodstream and transported to respiring cells in the muscles -> MORE glucose available for respiration -> MORE energy released -> MORE muscle contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

effect of adrenaline on the eyes

A

pupils dilate

46
Q

why do pupils dilate when adrenaline is released

A

allows MORE light into retina so you can see surroundings/danger BETTER

47
Q

effect of adrenaline on skin hairs

A

hairs stand up

48
Q

why do skin hairs stand up when adrenaline is released

A

in animals they appear larger and scarier

49
Q

effect of adrenaline on the brain

A

mental awareness (alertness) increases

50
Q

why does mental awareness (alertness) increase when adrenaline is released

A

can react faster

51
Q

what is homeostasis

A

the maintenance of a constant internal environment in the body

52
Q

what are some internal conditions that are controlled?

A

temperature, water, pH, oxygen, blood sugar, carbon dioxide

53
Q

how is homeostasis control achieved

A

using negative feedback mechanisms

54
Q

what is negative feedback

A

whenever a change occurs in the system, this automatically causes a corrective mechanism to start, which reverses the original shape and brings the system back towards the normal

55
Q

what is the name of the hormone responsible for controlling water levels in the blood

A

ADH (anti-diuretic hormone)

56
Q

what is the region of the brain that regulates the concentration of blood

A

hypothalamus

57
Q

water loss (negative feedback cycle):

A
  • loss of water means concentration of blood starts to increase
  • this is detected by special cells in the hypothalamus
  • these cells cause the pituitary gland to release MORE ADH
  • ADH causes the collecting duct to become MORE permeable to water
  • this means MORE water is reabsorbed back into the blood
  • this makes the urine more concentrated, less volume
58
Q

water gain (negative feedback cycle)

A
  • water gain means the concentration of the blood begins to decrease
  • this is detected by special cells in the hypothalamus
  • these cells cause the pituitary gland to release LESS ADH
  • less ADH causes the collecting duct to become less permeable to water
  • this means less water is reabsorbed back into the blood
  • makes urine more dilute, increased volume
59
Q

in humans, what is glucose stored as and where

A

stored as glycogen in the liver

60
Q

what happens when the body is short of glucose

A

it releases glucagon to convert glycogen into glucose

61
Q

what does insulin do

A

activates conversion of glucose to glycogen

62
Q

what does glucagon do

A

activates conversion of glycogen to glucose

63
Q

in mammals what part of the brain monitors the core body temp and where is it located

A

thermoregulatory centre - located in hypothalamus

64
Q

what happens when there is a change in temperature

A
  • temperature receptors in brain and skin send electrical impulses to hypothalamus
  • usually stimulates brain to change our behaviour (eg. find shade, have a cool drink, take off a layer of clothing)

when these changes are not enough:
- thermoregulatory centre in hypothalamus detects a change in temp of the blood running through it
- sends a signal via nerves to other organs in the body which then regulates temperature by physiological means

65
Q

what are homoeothermic organisms

A

warm blooded

66
Q

what are poikilothermic organisms

A

cold blooded

67
Q

does body temp fluctuate in homoeothermic organisms

A

less fluctuations -> body temp kept constant despite changes in surroundings

68
Q

does body temp fluctuate in poikilothermic organisms

A

yes

69
Q

are homoeothermic organisms endo or exotherms

A

endothermic

70
Q

are poikilothermic organisms endo or exotherms

A

exothermic

71
Q

do homoeothermic organisms have heating from inside or outside

A

inside -> trap heat from chemical reactions to warm body

72
Q

do poikilothermic organisms have heating from inside or outside

A

outside -> manage to keep core body temp more constant by adapting their behaviour

73
Q

advantages of being homeothermic

A
  • all chemical reactions in body can go on at a steady, predictable rate
  • metabolism doesn’t slow down in cold environments
  • stops enzymes from denaturing about a certain temp - kept at their optimum
  • warmer - metabolism increases
74
Q

functions of the skin

A
  • barrier to entry of disease-causing microorganisms
  • prevents water loss
  • tough outer layer to resist mechanical damage
  • sense organ - touch and temp changes
  • receptor and effector
  • leading role in temp regulation. responds to nerve impulses from hypothalamus. controls heat loss.
75
Q

role of capillary network in skin

A

blood flows through to radiate heat outside (vasodilation) and blood flow is restricted when cold (vasoconstriction)

76
Q

role of erector muscle in skin

A

tightens to give goose bumps when cold. controls movements of hair

77
Q

role of sweat pore in skin

A

hole where sweat is released

78
Q

role of hair in skin

A

stand up to trap air when cold to provide insulation as air is a poor conductor of heat. lie flat when hot

79
Q

role of epidermis in skin

A

tough outermost layer of skin, provides waterproof barrier and prevents the entry of pathogens

80
Q

role of dermis in skin

A

contains tough connective tissue, hair follicles and sweat glands. provides strength, stability and support

81
Q

role of sweat glands in skin

A

antibacterial properties. sebaceous gland, oils skin to prevent skin drying out. helps to cool us down

82
Q

role of fat cells in skin

A

provides insulation to help body conserve heat

83
Q

role of sensory cell in skin

A

receptor send messages to hypothalamus

84
Q

what happens when a rise in core body temp is detected

A

sweat glands produce a greater volume of sweat
- sweat evaporates off skin which requires energy - latent heat of vasodilation
- only cools skin down when it evaporates

hairs lie flat against skin surface
- relaxation of hair erector muscles

vasodilation
- increased blood flow to skins surface
- more heat is lost via radiation

85
Q

what happens when a decrease in core body temp is detected

A

hairs on skin stand up
- hair erector muscles contract
- hairs trap a layer of air next to the skin which acts as insulation
- much more effective in hairy mammals

bodies metabolism speeds up
- generates more heat (from chemical reactions)
- adrenaline stimulates this

vasoconstriction
- restricted blood flow to surface of skin
- less heat is lost via radiation

shivering
- muscles contract + relax rapidly
- generates a large amount of heat

86
Q

vasoconstriction

A
  • arterioles constrict, reduced blood flow to surface capillaries
  • little heat lost by radiation
87
Q

vasodilation

A
  • arterioles dilate, larger volume of blood flows through capillaries near skin surface
  • blood able to lose heat via radiation
88
Q

what is auxin

A

a hormone that plants respond to which controls growth in a plant

89
Q

what is the growth response to a directional stimulus in a plant called

A

a tropism

90
Q

what is it called when plants grow towards a stimulus

A

positive tropism

91
Q

what is it called when a plant grows away from a stimulus

A

negative tropism

92
Q

what is it called when plants grow in response to light

A

phototropism

93
Q

what is it called when plants grow in response to gravity

A

geotropism

94
Q

what are tropisms caused by

A

plant hormones

95
Q

what is the hormone responsible for the bending of shoots towards the light

A

auxin

96
Q

where is auxin produced

A

produced at the tip of the shoot and roots
it then diffuses down the stem to the region of growth

97
Q

what does auxin control and how

A

controls the growth of cells (cell elongation) by increasing the growth in shoots of plants and decreasing the growth in roots of plants

98
Q

what does auxin stimulate in the growing region

A

mitosis, as well as causing individual cells to elongate

99
Q

does the root of a plant have a response to light

A

most of the time there is not response

100
Q

does the shoot/stem/leaves have a response to light

A

grow towards the light -> positive phototropism

101
Q

does the root grow in response to gravity

A

grow towards gravity -> positive geotropism

102
Q

does the shoot/stem/leaves grow in response to gravity

A

grow away from gravity -> negative geotropism

103
Q

what happens when a plant has uniformed light

A

auxin distributes evenly on each side of the shoot -> mitosis is stimulated evenly on each side -> cell elongation is the same -> plants grow upwards towards light -> more photosynthesis

104
Q

what happens when a plant has unidirectional light

A

auxin accumulates on dark side -> more mitosis and cell elongation on dark side -> cells on dark side grow faster -> bend towards light -> more photosynthesis

105
Q

does auxin stimulate or inhibit growth in shoot due to gravity

A

stimulates

106
Q

does auxin stimulate or inhibit growth in roots due to gravity

A

inhibits

107
Q

auxin in roots (due to gravity)

A

auxin accumulates in lower side of roots

in roots the extra auxin inhibits growth -> this means cells on top will elongate faster, therefore grow faster, so the roots will bend downwards

108
Q

where does auxin accumulate due to gravity

A

lower side of root and shoot

109
Q

auxin in shoots (due to gravity)

A

auxin accumulates on lower side (auxin stimulates growth in shoots) -> more mitosis on lower side -> more cell growth -> causes shoot to bend upwards as lower side is growing faster

110
Q

why do roots need to grow down

A

to get water/minerals/anchorage

111
Q

why does shoot need to grow up

A

needs to grow towards sun -> photosynthesis

biology (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions