iGCSE Edexcel Biology > Coordination and response > Flashcards

Coordination and response Flashcards

(80 cards)

Study These Flashcards
1
Q

What is coordination and response

A

organisms detect and react to changes to survive using the nervous and endocrine systems

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

Homeostasis

A

the maintenance of a constant internal environment

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

Examples of homeostasis

A

body temperature blood sugar and water balance

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

Why homeostasis matters

A

keeps the body working well by maintaining stable conditions for processes like enzyme activity

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

Body temperature regulation

A

keeping the body around 37°C for enzymes to work properly

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

Water content regulation

A

kidneys filter water sweat cools the body

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

Co-ordinated response

A

needs a stimulus (change) a receptor (detects it) and an effector (carries out the response)

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

Stimulus

A

a change like heat light or sound

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

Receptor

A

detects the stimulus like eyes for light or skin for temperature

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

Effector

A

does the response like muscles moving or glands releasing hormones

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

Skin’s role in temperature regulation

A

sweating vasoconstriction and vasodilation

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

Vasodilation

A

blood vessels near surface widen to release heat and cool the body

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

Vasoconstriction

A

blood vessels near surface narrow to conserve heat

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

Sweating

A

sweat glands release water cooling the body as it evaporates
latent heat of evaporation

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

Sweating and cooling

A

evaporation of sweat takes heat away cooling you down

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

How does our body warm up

A

Vasoconstriction
Contract erector muscles
Shivering

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

How does our body cool down

A

vasodilation
Relax erector muscles
Sweating

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

How does shivering warm us up?

A

muscles contract rapidly - this doesn’t generate heat itself
respiration used to generate energy - exothermic reaction

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

Hypothalamus

A

brain area controls body temperature triggering responses like sweating or shivering

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

Nervous system in temperature regulation

A

thermoreceptors detect temperature changes and send signals to the hypothalamus for a response

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

Thermoreceptors

A

sensors that detect temperature changes and tell the brain to act

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

Why temperature regulation matters

A

enzymes work best at a steady 37°C too hot or too cold messes it up

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

Effectors’ response to temperature

A

muscles and glands shiver or sweat to regulate body temperature

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

Describe the process of how the body osmoregulates

A

Stimulus: blood contains high salt concentration

Receptor: Osmoreceptors in the hypothalamus detect this

Effector: Pituitary gland releases more ADH

Response: More water reabsorbed by collecting ducts in the kidneys -> less water lost in urine -> salt concentration decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is required in a co-ordinated response?
Stimulus, receptor, effector
26
What is geotropism
Growth toward/away from direction of gravity
27
What is phototropism
Growth toward/away from light
28
What does auxin do?
Stimulates cells to elongate (effect is more pronounced with more auxin)
29
Where is auxin produced in shoots?
Tip and diffuses down
30
Describe the role of auxin in phototropism
Auxin concentrates on the side of the stem receiving less light, causing that side to elongate and the tip to point directly towards the light source. When light shines evenly, auxin is distributed evenly so no change in tip direction.
31
Describe auxin's role in geotropism
In the stem, the auxin gathers at the bottom, causing the tip to point up. In the roots, the auxin gathers at the top, causing them to point down.
32
How does nervous communication control responses
Information is sent as electrical impulses along neurones. Rapid responses to stimuli Coordinates the activities of sensory receptors, decision-making centres in the CNS and effectors Used for things needing rapid responses Specific/localised effect Short duration
33
How does endocrine communication control responses
Information sent as hormones in blood stream Goes to whole body Can alter activity of one or more target organs Slow, not instant response
34
What do hormones do?
Transmit information from one part of the organism to another and bring about a change
35
What are hormones produced by?
Endocrine glands
36
What does the human nervous system consist of?
Central Nervous System: brain, spinal cord Peripheral Nervous System: all the other nerves
37
Nerve definition
Bundle of neurones
38
Describe how a stimulus triggers a response in the nervous system
Stimulus → receptor → sensory neurone → CNS → motor neurone → effector → response
39
Synapse definition
The gap between two neurones
39
What are neurotransmitters
Chemical messengers that diffuse across synapses and bind to the next neurone, causing a new electrical impulse to be generated
40
What is a reflex/involuntary response?
Response that does not involve conscious part of the brain as coordinator - awareness of the response occurs after it happens
41
Why is it good that reflex responses are involuntary and rapid?
Helps minimise damage to aid survival
42
Describe the reflex arc
1. Stimulus detected by receptor 2. Sensory neurone sends impulse to spinal chord 3. Electrical impulse passed to a relay neurone 4. Relay neurone passes to motor neurone 5. Motor neurone carries impulse to the effector (muscle/gland)
43
What is the Conjunctiva
A clear membrane that covers the white of the eye and the inside of the eyelids; it lubricates the eye and provides protection from external irritants
44
What is the cornea
transparent, curved layer at the front of the eye that refracts light as it enters the eye
45
What is the Pupil
circular opening in the centre of the iris that allows light to enter the eye
46
What is the sclera
the strong outer wall of the eyeball that helps to keep the eye in shape and provides a place of attachment for the muscles that move the eye
47
What is the iris
controls how much light enters the pupil
48
What is the lens
transparent disc that can change shape to focus light onto the retina
49
What is the ciliary muscle
a ring of muscle that contracts and relaxes to change the shape of the lens
50
what are the Suspensory ligaments
ligaments that connect the ciliary muscle to the lens
51
what is the retina
contains receptor cells sensitive to light
52
what is the fovea
region of the retina that contains densely packed cones (allows eyes to see in good detail and colour)
53
what is the optic nerve
carries impulses between the eye and the brain
54
what is the blind spot of the eye
the point at which the optic nerve leaves the eye, where there are no light receptor cells
55
How can the shape of the lens be changed?
When the suspensory ligaments become tight or loose Brought about by contraction/relaxation of ciliary muscles
56
How does the lens focus on near objects
Ciliary muscles contract (ring decreases in diameter) -> suspensory ligaments loosen -> suspensory ligaments pull less on lens -> lens becomes thicker
57
When the lens is not pulled by the suspensory ligaments, is it thick or thin?
Thick
58
How does the lens focus on further away objects?
Ciliary muscels relax (ring increases in diameter) -> suspensory ligaments tighten -> suspensory ligaments pull on lens -> lens becomes thinner
59
What is the pupil reflex
Reflex action carried out to protect retina from damage.
60
How does the iris react in dim light?
Radial muscles of iris contract Circular muscles of iris relax Pupil is dilated
61
How does the iris react in bright light?
Radial muscles of iris relax Circular muscles of iris contract Pupil is constricted
62
Where in the skin are touch and pressure receptors located?
Dermis
63
Where are the free nerve endings located in skin?
Epidermis
64
Name 3 cooling mechanisms in humans
Vasodilation Sweating Flattening of hairs
65
How does vasodilation/constriction work?
Muscles in the walls of arterioles relax/contract, dilating/constricting the arterioles to allow more/less blood to flow through capillaries and lose more/less heat to the environment via radiation
66
Arteriole definition
Small blood vessels connecting arteries to capillaries
67
How does sweating work?
Sweat is secreted by sweat glands in the skin. Heat is lost through latent heat loss of evaporation.
68
What is sweat made up of
Mostly water with some salt including urea
69
How does flattening of hair work
hair erector muscles relax causing hairs to lie flat Stops them trapping air and allows air to circulate over the skin and allows heat to leave by radiation
70
What are 3 warming mechanisms in humans?
Vasoconstriction Shivering Erection of hairs
71
How does shivering work?
Reflex action Muscles contract in a rapid and regular manner Exothermic metabolic reactions required to power this shivering generate heat to warm blood and raise body temp
72
How does erection of hairs work?
Hair erector muscles in the skin contract, causing hairs to stand on end Insulating layer formed over skin's surface by trapping air between hairs, stops heat loss by radiation
73
What are the effects of adrenaline on the body?
Increased heart rate and breathing rate: delivers glucose and oxygen to muscle cells faster and removes CO2 more efficiently redirects blood flow to muscles and away from non-essential organs: muscles receive more oxygen + glucose dilation of blood vessels in muscels: more blood -> glucose + oxygen breaking down of stored glycogen -> glucose in liver and muscle cells (glucose released by liver -> active muscle cells
74
What is the effect of insulin
If blood glucose gets too high: cells in pancreas detect this -> pancreas produces insulin -> insulin stimulates muscles and liver to take up glucose from the blood and store as glycogen
75
Why must blood glucose levels be kept in a narrow range?
too high: body loses water by osmosis too low: brain doesn't get enough glucose for respiration
76
What is the effect of testosterone
Produced in testes Responsible for stimulating development of male reproductive organs and secondary sexual characteristics
77
What is the effect of progesterone
Produced in ovaries Responsible for maintaining uterine lining during pregnancy + prevents further ovulation
78
What is the effect of oestrogen
Produced in ovaries Responsible for: development of secondary sexual characteristics regulating menstrual cycle (stimulating the repair of the uterine lining after menstruation + helps control the release of eggs by influencing other hormones (FSH, LH))
79
iGCSE Edexcel Biology
flashcards
Decks in class (22)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions