Topic 5 - Homeostasis Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What is homeostasis?

A

The regulations of conditions inside a body or cell

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

Why is homeostasis important?

A

To maintain optimum conditions in response to an internal or external conditions

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

What three things does homeostasis control?

A

-blood glucose concentration
-temperature
-water levels

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

What is a receptor?

A

A cell which detects a stimuli

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

What is an effector?

A

Muscles or glands, which bring about responses which
restore optimum levels.

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

What is the point of the nervous system?

A

The nervous system enables humans to react to their surroundings and
to coordinate their behaviour.

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

Name two parts of the central nervous system

A

-spinal cord
-brain

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

How are messages passed through the nervous system?

A

Via. electrical impulses

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

What is the reflex arc in order

A

Stimuli, receptor, sensory neurone, synapse, relay neurone, synapse, motor neurone, effector, response

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

What is a reflex action?

A

Automatic and rapid actions which do not involve the conscious part of the brain.

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

What is a synapse?

A

The gap between two neurones where messages are sent by chemical diffusion

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

Why are reflex actions important?

A

To avoid damage to the cells

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

Why do synapses slow down a reflex action?

A

Chemical diffusion is slower than electrical impulses

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

What is the brain made up of?

A

Millions of interconnected neurones

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

What are the three main parts of the brain?

A

-Cerebral cortex
-Cerebellum
-Medulla

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

What is the function of the cerebral cortex?

A

conscious thought

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

What is the function of the cerebellum?

A

balance and movement

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

What is the function of the medulla?

A

unconscious activities such as breathing, heart rate.

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

Why is investigating brain function and treating brain damage and disease problematic?

A

The complexity and delicacy of the brain makes investigating and treating brain disorders very difficult.

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

What is the function of the retina?

A

retina- detects light

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

What is the function of the optic nerve?

A

optic nerve- carries electrical impulses to the CNS

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

What is the function of the cornea?

A

cornea- refracts (bends) light as it enters the eye

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

What is the function of the sclera?

A

sclera- outer layer protects the eye

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

What is the function of the iris?

A

iris- controls how much light enters the eye

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

What is the function of the ciliary muscles?

A

ciliary muscles- contract or relax to control focusing

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

What is the function of the suspensory ligaments?

A

suspensory ligaments- connect cliliary muscle to the lens

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

what part of the body controls and monitors temperature?

A

The thermoregulatory centre in the brain

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

where are temperature receptors located in the body?

A

In the skin

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

What 2 things happen when body temperatures are too high

A

Vasodialation and sweating

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

What 3 things happen when body temperatures are too low?

A

Vasoconstriction, shivering and hairs standing on end.

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

How are messages passed on in the human endocrine system?

A

Through hormones in the bloodstream

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

What are the six glands and the hormone they produce?

A

Pituitary gland - many hormones
Thyroid - Thyroxin
Adrenal - Adrenaline
Pancreas - insulin
Ovaries - oestrogen
Testes - testosterone

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

Which is faster the endocrine or the nervous system?

A

The nervous system as electrical impulses travel much faster

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

What is accommodation?

A

How the eye can adjust to focus on things at different distances

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

How do we focus on objects at far distances?

A

The ciliary muscles relax

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

How do we focus on objects at close distances?

A

The ciliary muscles contract

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

What are two common defects of the eyes?

A

Myopia (short-sightedness): the light is refracted too much, so the focal point is in front of the retina. Hyperopia (long-sightedness): the light is not refrated enough, so the focal point is beyond the retina.

37
Q

What is myopia?

A

Myopia (short-sightedness): the light is refracted too much, so the focal point is in front of the retina.

38
Q

What is hyperopia?

A

Hyperopia (long-sightedness): the light is not refrated enough, so the focal point is beyond the retina.

39
Q

What are ways to correct vision?

A

Glasses or laser eye surgery

40
Q

What part of the body controls glucose levels

A

the pancreas

41
Q

What happens if blood glucose concentration is too low?

A

the pancreas
produces the hormone glucagon that causes glycogen to be converted into glucose and released into the blood.

42
Q

What is the treatment for type 1 diabetes?

A

Insulin injection

42
Q

What happens if blood glucose concentration is too high?

A

the pancreas produces insulin that causes glucose to move from the blood into the cells. In the liver excess glucose is converted to glycogen for storage.

43
Q

What hormone is produced when blood glucose is too high

A

insulin

43
Q

What is type 1 diabetes?

A

A disorder in which the pancreas fails to produce sufficient insulin.

44
Q

What is type 2 diabetes?

A

It occurs when the body cells no longer respond to insulin produced by the pancreas.

45
Q

What is a risk factor for type 2 diabetes?

A

Obesity

46
Q

How can type 2 diabetes be controlled?

A

A carbohydrate controlled diet and an exercise regime

47
Q

What is released when blood glucose concentration is too low?

A

Glucagon

48
Q

What happens to blood cells when there is too much water?

A

The cells gain water by osmosis and burst

49
Q

What happens to blood cells when there is too little water?

A

The cells lose water by osmosis and shrivel.

49
Q

In what 3 ways is water lost?

A

-breathing (exhalation)
-sweating
-urination

50
Q

How are excess ions and urea lost ?

A

-sweating
-urination

51
Q

How is excess protein dealt with in the body?

A

Protein is converted into amino acids which turns into ammonia through the process of deamination. The ammonia is toxic so it is immediately converted into urea which can be safely excreted.

52
Q

What is produced in the kidneys and what does it contain?

A

Urine, containing water, urea and ions

53
Q

What two processes take place in the kidneys?

A

Filtration - ions, water, glucose and urea are pushed out the blood stream into the kidney tubule
Reabsorbtion - some ions some water and glucose is reabsorbed back into the bloodstream

54
Q

What does ADH do to the permeability of the tubule?

A

ADH increases the permeability of the kidney tubule

55
Q

What happens to ADH levels when there is too little water?

A

The pituitary gland releases more ADH which make the tubule more permeable meaning that more water will be reabsorbed so water levels return to normal.

56
Q

Describe the process of dialysis

A

Blood is filtered by a machine and returned to the body. Must be done at least 3 times a week.

57
Q

What are the two treatments for kidney failure?

A

Dialysis and kidney transplant

58
Q

What is an advantage and disadvantage of dialysis

A

+ provides help whilst waiting for a donor so the patients body can function
- Very restrictive lifestyle , 3 times a week

59
Q

What is an advantage and disadvantage of kidney transplants?

A

+ Patients can lead a normal lifestyle, cheaper long term
- Shortage of kidney donors, risk of rejection

60
Q

Name the male reproductive hormones and its function and where it is produced

A

Testosterone - produced by testes, sperm production begins and voice deepens

61
Q

Name the female reproductive hormones and its function and where it is produced

A

Oestrogen - produced by the ovaries, menstrual cycle begins, breast enlarge

61
Q

What is ovulation?

A

The release of an egg from the ovary

62
Q

How long des the menstrual cycle last?

A

Aprox. 28 days

63
Q

What is the role of FSH

A

FSH: causes egg to mature in the ovary.

64
Q

What is the role of LH

A

LH: causes ovulation.

65
Q

What is the role of oestrogen and progesterone?

A

Oestrogen and progesterone: develop and maintain uterus lining

66
Q

How do all the female hormones interact during the menstrual cycle?

A

FSH: causes oestrogen to be released. Oestrogen: stops FSH and starts LH production. LH: stops oestrogen and casues progesterone release.

67
Q

Name two non hormonal contraceptives

A

Condoms, copper coil

68
Q

Name 3 types of hormonal contraceptives

A

Pill, Patch, injection

69
Q

What is the role of hormones in hormonal contraception?

A

The hormones inhibit the release and maturity of an egg

70
Q

What is an IUD and what does it prevent?

A

A copper IUD prevents the implantation of a fertilised egg in the uterus

71
Q

What are two other methods of contraception?

A

Abstinence (not having sex), sterilisation (permanently restricting pregnancy)

72
Q

How is IVF taken place?

A

An egg is taken from a woman and fertilised by sperm in a lab. An embryo can then develop in the lab and be inserted into a uterus

72
Q

What are some drawbacks of IVF?

A

-Expensive
-Low success rate
-Emotionally and Physically straining

73
Q

How are hormones used in IVF

A

To stimulate egg release and maturity

73
Q

What is IVF?

A

In-vitro-fertilisation, fertilising an egg outside the female body

74
Q

What is the role thyroxine ?

A

To stimulate basal metabolic rate

75
Q

What is the role of adrenaline?

A

To increase heart rate in stressful situations

76
Q

What is a negative feedback cycle?

A

A mechanism to lower levels of something which is too high, and raise levels of something that is too low.

77
Q

Name two examples of negative feedback cycles

A

-Menstural cycle
-Control of water levels
-Blood glucose concentration

78
Q

What is phototropism?

A

The plants response to light, plant will grow towards the light

79
Q

What is gravitropism?

A

The plants response to gravity, shoots grow away from gravity, roots grow towards gravity

80
Q

What causes gravitropism and phototropism?

A

Uneven distribution of auxin

81
Q

What is the role of gibberellins ?

A

Initiating seed germination

82
Q

What is the role of ethene?

A

Controls cell division and the ripening of fruits

83
Q

Describe the use of auxins

A

-as weed killers
- as rooting powders
- for promoting growth in tissue culture.

84
Q

Describe the use of ethene

A

used in the food industry to control ripening of fruit during
storage and transport.

85
Q
A