Brainscape's Knowledge GenomeTM

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


See full index

GCSE - Biology > Topic 7 - Animal Coordination, Control And Homeostasis > Flashcards

Topic 7 - Animal Coordination, Control And Homeostasis Flashcards

1
Q

What is the endocrine system?

A

A network of glands that produce and secrete hormones into the bloodstream

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

What is a hormone?

A

A chemical signal produced by endocrine glands and released into the blood
Travels to target organ and binds to receptors on effectors initiating a respose

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

Compare the endocrine and nervous systems (4)

A

Endocrine - uses HORMONES, hormones travel in BLOODSTREAM to target organ, SLOWER response, lasts until ALL HORMONES BROKEN DOWN (long time)
Nervous system - uses NERVE IMPULSES, these travel via NEURONS to effectors, FASTER response, lasts until NERVE IMPULSE STOPS (short time)

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

Whats the pituitary gland?

A

Described as the ‘master gland’

Endocrine gland that produces hormones which control other glands (eg adrenal glands)

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

What are the adrenal glands?

A

Endocrine glands that produce adrenaline

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

Where are the adrenal glands located?

A

Above the kidneys

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

Whats adrenaline?

A

Hormone produced by adrenal glands involved in ‘fight ot flight’ respose

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

State 4 effects of adrenaline on body

A

Increased HR
Increased BP
Increased blood flow to muscles
Increased blood glucose levels

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

Describe how adrenaline increases HR and BP

A

Secreted by adrenal glands and travels in blood to heart.
Binds to specific receptors on cells in heart.
Causes heart muscle to contract more forcefully and frequently

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

Describe how adrenaline increases respiration at muscle tissues

A

Binds to specific receptors on cells in liver.
Triggers breakdown of glycogen stores + release of glucose. (Levels increase)
Increased HR causes greater blood flow to muscles so they receive more oxygen and glucose for respiration

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

What is negative feedback?

A

Corrective mechanism allowing only small shifts from set point.
Reverses a change in conditions

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

What is the thyroid gland?

A

Endocrine gland that produces thyroxine

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

Where is the thyroid gland located?

A

In the neck

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

What is thyroxine

A

A hormone secreted by the thyroid gland that controls metabolic rate, HR and temp

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

What is metabolic rate?

A

Rate at which biochemical reactions occur in cells

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

Describe how thyroxine is released

A

Hypothalamus secretes TRH
TRH stimulates secretion of TSH from pituitary gland
TSH stimulates the release of thyroxine from the thyroid gland

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

What does TRH stand for?

A

Thyrotropin releasing hormone

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

What does TSH stand for

A

Thyroid stimulating hormone

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

Describe how a negative feedback system controls blood thyroxine levels

A

If increase, TRH + TSH secretion is inhibited. Less thyroxine produced by thyroid gland. Levels return to normal
If decrease, TRH + TSH secretion increased. More thyroxine produced by thyroid gland. Levels return to normal

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

How do the ovaries act as an endocrine gland?

A

Secrete oestrogen into bloodstream

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

How do testes act as an endocrine gland?

A

Secrete testosterone into bloodstream

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

What is the menstrual cycle

A

Cycle in women (typically 28 days) involving:

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

Describe the stages of the menstrual cycle:

A

1-4: if fertilisation + implantation dont occur, uterus lining sheds and egg expelled with it
4-14: uterus lining thickens and blood vessels grow in prep for implantation of egg
14: egg released from follicle into oviduct
14-28: uterus lining maintained so implantatiom can occur

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

Name the hormones that control the menstrual cycle (4)

A

Follicle stimulating hormone (FSH)
Oestrogen
Luteinising hormone (LH)
Progesterone

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

Describe the role of FSH in the menstrual cycle

A

Secreted by pituitary gland
Transported in bloodstream to ovaries
Triggers development of follicle in ovaries which releases oestrogen

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

Describe the role of oestrogen in the menstrual cycle

A

Secreted by ovaries
Repairs and thickens uterus lining
Inhibits secretion of FSH from pituitary gland
Stimulates secretion of LH from pituitary gland

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

Describe the role of LH in the menstrual cycle

A

Surge in LH triggers ovulation

Stimulates folice remains to develop into corpus leteum which then secretes progesterone

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

Whats a corpus luteum?

A

Temporary endocrine structure
Mass of cells that releases progesterone
Degenerates after a few days

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

Describe the role of progesterone in the menstrual cycle

A

Secreted by corpus luteum
Stimlates growth of blood vessels in uterus lining
Inhibits release of FSH + LH
If no implantation - progesterone kevels decrease and uterus lining sheds. FSH increases and cycle restarts

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

What happens to progesterone levels if fertilisation and implantation occur?

A

Placenta produces progesterone so levels remain high. Prevents further ovulation and maintains uterus lining.

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

What are contraceptives?

A

Method or device utilised to prevent pregnancy

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

Which hormones can be taken to prevent pregnancy?

A

Progesterone on its own

Progesterone combined w oestrogen

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

How does progesterone prevent pregnancy?

A

Harder for sperm to enter uterus (cervical mucus thicker)
Thins uterine lining (less chance of egg implantation)
Prevents ovulation in some women

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

How does oestrogen prevent pregnancy?

A

Inhibits FSH, preventing ovulation

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

Outline how progesterone can be administered as a contraceptive (2)

A

Mini pill taken daily

Injection

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

Outline how progesterone and oestrogen can be administered as a contraceptive (2)

A 
Combined pill (taken continuously for 21 days then paused for 7 days)
Skin patch (worn continuously for 3 weeks then without for 1 week)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are the benefits of hormonal contraceptive methods (3)

A

99% effective when used properly
Generally last longer than non hormonal methods
Used to treat other conditions eg painful/heavy periods

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

What are the risks of hormonal contraceptive methods? (4)

A

Side effects eg acne/bloating
Dont protect against STIs
May involve uncomfortable medical procedures
Not effective if used incorrectly

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

Describe the barrier methods of contraception

A

Prevent sperm and egg meeting

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

2 examples of barrier methods of contraception

A 
Condoms
Diaphragms (fit over cervix)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Benefits of barrier methods of contraception? (3)

A

Condoms simple and quick
Condoms prevent spread of STIs
No side effects

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

What is the main risk of barrier methods of contraception?

A

Less effective than hormonal methods

Eg condom may split while in use

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

What 2 methods (involving hormones) are used to treat infertility?

A

Clomifene therapy

IVF

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

Describe the role of hormones in IVF

A

FSH + LH given to woman to stimulate egg production and ovulatiom
Eggs retrieved from womans ovaries and fertilised in vitro
Resultant embryo transferred to womans uterus

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

Outline clomifene therapy

A

Prescription of clomifene drug to women who dont ovulate regularly
Stimulates secretion of more FSH + LH which triggers egg production and ovulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What is homeostasis?

A

Maintenance of stable internal environment in the body despite changes in internal + external conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Why is homeostasis important?

A

To ensure optimum conditions for enzymes and cellular processes in the body

48
Q

State 3 conditions in the body that must be controlled by homeostasis

A

Temperature
Blood glucose concentration
Water levels

49
Q

That is thermoregulation?

A

Maintenance of core body temperature

50
Q

Why must body temperature be controlled?

A

Enzymes work best at their optimum temp. Deviations from this optimum temp decrease rate of enzyme controlled reactions.

51
Q

What is the optimum temp for enzymes in the human body?

A

37°C

52
Q

What does the maintenance of an ideal body temp depend on?

A

A negative feedback system involving:
Receptors
Hypothalamus
Effectors eg sweat glands

53
Q

Where are temperature sensitive receptors located?

A

Skin - epidermis (outer layer) and dermis (under)

Hypothalamus

54
Q

What is the fuction of receptors in the skin and hypothalamus?

A

Detect changes in blood temp and send info to hypothalamus

55
Q

What is the function of the hypothalamus

A

It coordinates info from the receptors and sends instructions to effectors

56
Q

What is the function of the effectors?

A

Produce a response to counteract the change in blood temperature and return it to the set point

57
Q

Outline the responses of the body to an increase in temp above 37°C (3)

A

Vasodilation
Sweating
Efector muscles relax - hairs lie flat

58
Q

What structure produces sweat

A

Sweat glands found in the dermis

59
Q

How is sweat released from the skin?

A

Pores in epidermis release sweat onto skin surface - evaporates

60
Q

How does sweating help reduce body temp?

A

Heat energy is ised to evaporate sweat

Increased heat transfer from skin to environment decreases body temp

61
Q

What is vasodilation?

A

Dilation of blood vessels near skin surface
Blood flows closer to skin surface
Greater heat loss to surroundings

62
Q

Outline the responses of the body to a ecrease in temp below 37°C (4)

A

Vasoconstriction
Shivering
Hair erector muscles contract
Little sweat is produced

63
Q

How does shivering help increase body temp?

A

Involuntary muscle contractions generates heat energy from respiration

64
Q

How does the contraction of hair erector muscles help increase body temp?

A

Hairs stand on end creating pockets of air between hairs and a layer of insulation

65
Q

What is vasoconstriction?

A

Constriction of blood vessels near skin surface
Less blood flows close to skin surface
Less heat loss to surroundings

66
Q

Which organ is responsible for the maintenance of blood glucose concentrations?

A

Pancreas

67
Q

How are blood glucose concentrations controlled?

A

Controlled by hormones insulin and glucagon - secreted by pancreas

68
Q

Insulin and glucagon are antagonistic hormones. What does this mean?

A

They have opposite effects which counteract one another

69
Q

Describe the role of insuli in the regulation of blood sugar levels

A

Causes liver and muscle cells to increase their uptake of glucose from the blood
Glucose is converted into glycogen, a storage molecule

70
Q

Describe the role of glucagon in the regulation of blood sugar levels

A

Causes breakdown of glycogen to glucose in liver

Glucose released into blood

71
Q

What is the control of blood glucose concentration an example of?

A

Negative feedback

72
Q

Describe what happens when blood glucose concentrations become too high

A

Blood glucose concentration increases above set pt.
Pancreas secretes insulin + stops producing glucagon.
Liver and muscle cells increase uptake of glucose.
Glucose converted to glygogen and stored.
Some may be stored as lipid in tissues.
Concentration decreases, returning to normal level.

73
Q

Describe what happens when blood glucose concentrations become too low

A

Concentration decreases below set pt.
Pancreas secretes glucagon + stops producing insulin.
Liver cells convert glycogen into glucose - released into blood.
Concentration increases, returning to normal level

74
Q

What is diabetes?

A

Condition where homeostatic control of blood glucose levels stops working

75
Q

What is the cause of type 1 diabetes?

A

Pancreas does not produce enough insulin

76
Q

How is type 1 diabetes treated? (3)

A

Daily insulin injections at meal times
Limiting intake of refined sugars
Regular exercise

77
Q

What is the cause of type 2 diabetes?

A

Person develops insulin resistance or doesnt produce enough insulin (often due to obesity)

78
Q

How is type 2 diabetes treated? (3)

A

Balanced diet (eating less simple sugars + more complex carbs)
Exercise
Medication or insulin injections (less effective)

79
Q

How does exercise help control diabetes?

A

Increases respiration in muscle cells

Excess glucose removed from blood to produce emergy in form ATP

80
Q

Why are type 2 diabetics advised to replace simple carbs with more complex carbs?

A

Simple carbs = broken down quickly so can raise blood glucose levels rapidly
Complex carbs = broken down slower so have reduced effet on blood glucose levels

81
Q

What is the BMI?

A

Body Mass Index = value based on height and mass used to categorise a person as underweight, normal weight, overweight or obese

82
Q

How is BMI calculated?

A

BMI = mass (kg) / height² (m)

83
Q

What BMI values indicate obesity and an increased risk of type 2 diabetes?

A

> 30

84
Q

How is an individuals waist-to-hip ratio calculated?

A

waist circumference / hip circumference (cm)

85
Q

What does a waist-to-hip ratio higher than 1.0 in males or 0.85 in females indicate?

A

Abdominal obesity

Increased risk of developing type 2 diabetes

86
Q

What is osmoregulation

A

Maintenance of constant water levels in the body fluids of an organism

87
Q

Why is osmoregulation important?

A

Prevents cells bursting or shrinking when water enters or leaves by osmosis

88
Q

Describe what happens to an animal cell if its placed into a solution with a higher water concentration

A

Water molecules move down their water concentration gradient into the cell from solution by osmosis
Pressure inside cell increases + cell bursts (lysis)

89
Q

Describe what happens to an animal cell if its placed into a solution with a lower water concentration

A

Water mo,ecules move down their water concentration gradient out of cell into solution by osmosis
Pressure inside cell decreases, cell shrinks (crenation)

90
Q

Describe what happens to an animal cell if its placed into a solution with an equal water concentration

A

No net movement of water molecules into or out of the cell

91
Q

Describe the function of the kidneys

A

Removes toxic waste substances from body
Alters blood water levels
Alters blood ions levels

92
Q

What is urine?

A

Waste product of the kidney that contains urea, excess water and excess ions

93
Q

How is urea produced?

A

In the liver, from breakdown of excess amino acids

94
Q

What are the 6 structures of the urinary system?

A 
Kidney
Renal vein
Renal artery
Ureter
Urethra
Bladder
95
Q

What is the function of the renal artery?

A

Supplies blood to kidneys

96
Q

Whats the function of the renal vein?

A

Drains blood from kidneys

97
Q

Whats the function of the ureter?

A

Takes urine to bladder from kidneys

98
Q

Whats the function of the urethra?

A

Releases urine from bladder out of body

99
Q

What is a nephron?

A

Functional unit of kidney where filtration and selective reabsorption takes place

100
Q

Describe filtration in kidneys

A

Blood flows through glomerulus under high pressure.

Small molecules eg urea/glucose water and ions are filtered out of blood and into Bowmans capsule of nephron

101
Q

Why do large molecules eg red blood cells remain in the blood?

A

They are too large to fit through the pores in the capillary walls

102
Q

Which substances are selectively reabsorbed from the nephron tube?

A

All sugars
Some water
Some ions

103
Q

What happens to the molecules not selectively reabsorbed?

A

Travel down kidney tubule as urine and are transported to bladder via ureter. They are stored and eventually excreted.

104
Q

How is the concentration and volume of urine controlled?

A

Controlled by the secretion of anti-diuretic hormone (ADH)

105
Q

What produces ADH

A

Pituitary gland

106
Q

Describe how ADH affects the reabsorption of water from the kidney tubules

A

ADH increases the permeability of the collecting ducts, enabling more water to be reabsorbed into the blood

107
Q

What is required to maintain the ideal water content of blood?

A

A negative feedback system involving:

  • receptors in the hypothalamus
  • hypothalamus
  • effector ie pituitary gland
108
Q

Describe the negative feedback loop which occurs when low blood water concentration is detected

A

Receptors detect low blood water content + send info to hypothalamus - this coordinates the info and sends instructions to the pituitary gland - increases ADH secretion - increases collecting duct permeability - more water reabsorbed.
Blood water content increases + more concebtrated urine is produced

109
Q

How can kidney failure be treated?

A

Kidney dialysis

Kidney transplant

110
Q

What is kidney dialysis

A

A machine artificially filters a patients blood

111
Q

How does kidney dialysis work?

A

Selectively permeable barrier separates pateints blood from dialysis fluid.
Materials are exchanged across the barrier eg urea, excess ions and water move out of blood and into dialysis fluid.
Large cells and proteins remain in blood

112
Q

Describe the composition of dialysis fluid

A

Same concentration of glucose and ions as in normal blood plasma
No urea

113
Q

What does a kidney transplant involve?

A

Taking a kidney from a living donor or someone recently deceased and implanting it into the patient.

114
Q

What is the risk associated with kidney transplants?

A

Risk of the body rejecting the transplanted kidney

115
Q

What precautions are taken to minimise the risk of rejection?

A

Tissue typing ensures that the transplanted organ is compatible with the recipient.
Immunosuppressant drugs help prevent the immune system from rejecting the organ

GCSE - Biology (7 decks)

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