B1.2 Nerves and hormones Flashcards

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1
Q

Name the five senses

A
  • Hear (sound)
  • Smell (chemicals for smell)
  • Taste (chemicals for taste)
  • Touch (temperature changes)
  • Sight (light sensitivity)
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2
Q

What is the CNS?

A

The central nervous system

The brain and spinal cord

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3
Q

What is the PNS?

A

The peripheral nervous systems

Transmits electrical impulses to and from the CNS

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4
Q

What are receptors?

A

Groups of cells that respond to a particular stimulus

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5
Q

What do the sensory neurones do?

A

Transmit the electrical impulses from the receptors in the sense organs to the spinal cord and brain

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6
Q

What are the relay neurones?

A

The nerve cells that transmit the electrical signals from sensory neurones to the motor neurones

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7
Q

What are the synapses?

A

The connection between two neurones
It allows the electrical impulses to reach the spinal cord
Chemicals are released one end and diffuse across to the other

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8
Q

What is a neurotransmitter?

A

Chemicals produced that transmits the electrical signal across the synapse

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9
Q

What does the myelin sheath do?

A

Insulates the electrical impulse

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10
Q

What does the axon do?

A

Transports the impulses

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11
Q

What do the motor neurones do?

A

Transmits electrical signals through the CNS to the effector cells of muscles or glands

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12
Q

What are the effectors?

A

The muscles or glands that respond to the electrical impulse

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13
Q

What is a reflex action?

A

an automatic response to a stimuli

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14
Q

Describe the process of the sense organs (5)

A

1) A stimulus changes in the environment
2) The receptor sends impulses along the neurones
3) The sensory receptors detect the change
4) The message goes to the CNS which coordinates information
5) The CNS send impulses to the motor neurones to the effectors which then respond

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15
Q

Describe the reflex arc (7)

A

1) stimulus
2) receptor
3) sensory neurone
4) relay neurone
5) motor neurone
6) effector
7) response

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16
Q

What does homeostasis mean?

A

Keeping a constant internal environment

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17
Q

What are the things that have to be maintained? (4)

A
  • Water levels
  • Temperature
  • Blood sugar levels
  • Salt/ion levels
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18
Q

What does the kidney do?

A

Regulates water and mineral salt concentration

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19
Q

What does the skin do?

A

Regulates body temperature

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20
Q

What do the liver and pancreas do?

A

Regulate blood glucose levels

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21
Q

How is water taken in and lost?

How is too much water dealt with?

A
  • Taken in through food and drink
  • Lost in breath, sweat and urine

-Excess water is removed by the kidneys and stored on the bladder as urine

22
Q

How is ion (salt) taken in and lost?

How is too much ions dealt with?

A
  • Taken in through food and drink
  • Lost in sweat and urine

-Excess ions are removed by the kidneys and passed out in urine

23
Q

Where does glucose come from?

A

Food and drink

24
Q

Where is insulin made?

A

In the pancreas

25
Q

What can eating too much carbohydrates cause?

A

Increased blood sugar levels

26
Q

What can low weight cause?

A

Decreased blood sugar levels

27
Q

What happens when your blood sugar is too high?

A

The pancreas releases insulin and cells take in glucose from the blood
Body can’t function if they are too high

28
Q

What happens if your blood sugar levels are too low?

A

The pancreas releases glucagon, your liver then releases glucose into the blood stream
Chemical reactions can’t work properly if they are too low

29
Q

What is glucose?
What is glycogen?
What is glucagon?

A

Glucose = Sugar found in starchy foods

Glycogen = The storage of glucose (glucose can’t be stored as it is insoluble)

Glucagon = A hormone that breaks down glycogen into glucose

30
Q

What is the normal body temperature and why?

A

37 degrees so that chemical reactions can take place

31
Q

What is body temperature controlled by?

A

The thermoregulatory centre in the brain

32
Q

What does the thermoregulatory centre have?

A

Special receptors that are sensitive to temperature change

33
Q

What happens to the body when the temperature it too low and want to warm up? (3)

A
  • Shiver = muscles move creating more energy and more heat
  • Hair stand up = trapping heat
  • Blood vessels near the surface become tighter = blood flow is slower less heat evaporates (looks paler)
34
Q

What happens to the body when the temperature is to high and wants to cool down? (3)

A
  • Enzymes change shape (denature) = can’t work properly
  • Blood vessels dilate = can sweat and get rid of heat (looks red blood vessels near surface)
  • Hairs lie flat = doesn’t trap heat
35
Q
What happens during the menstrual cycle? 
Day 1-6 
Day 7-13
Day 14 
Day 15 onwards
A

Day 1-6
Menstruation eggs are immature FSH produced to make eggs mature

Day 7-13
Proliferation (build up)
Egg is mature oestrogen is released to stop FSH and multiple egg release starts LH

Day 14 ovulation LH highest maintains lining

Day 15 onwards
Uterus lining maintained

36
Q
What do these hormones do and where are they secreted from? 
FSH 
Oestrogen 
LH
Progesterone
A

FSH = secreted from pituitary gland

  • causes ovary to secrete oestrogen
  • matures the egg

Oestrogen = secreted from ovary

  • causes pituitary gland to secrete LH
  • builds lining of uterus

LH = secreted from pituitary gland
-releases an egg from the ovary

Progesterone = secreted from ovary
-maintains the lining of uterus

37
Q

Describe the process of IVF

A

1) Eggs are taken from women and fertilised outside of the body
2) It is then put back into the women

38
Q

What are some disadvantages of IVF? (2)

A
  • Can be emotionally and physically demanding

- Not recommended for over the age of 42

39
Q

Describe birth control and advantages of it

A

Oestrogen pills are taken to stop ovaries releasing eggs

  • less than 1 out of 100 pregnancies
  • safe
  • very effective
40
Q

Describe fertility treatment and disadvantages

A

Contains FSH stimulated egg to mature ovaries

- Increases premature babies

41
Q

What is tropism?

A

Plants are sensitive to their environment so they can make adjustments to survive

42
Q

What are auxins?

A

Plant hormones used for growth
Tips of stem and roots
Roots = low concentration promotes growth
Stem = high concentration promotes growth

43
Q

What is gravitropism?

A

Plants growth in response to gravity
Stems grow away from gravity (negative gravitropism)
Roots grow towards gravity (positive gravitropism)

44
Q

What is phototropism?

A

Plants growth in response to light
Roots grow away from light, less chance of drying out (negative phototropism)
Stems grow towards light for photosynthesis (positive phototropism)

45
Q

What happens with the sun and auxins?

A
  • Sunlight breaks down auxins
  • The side of the tip with most sunlight will have least amount of auxin
  • more growth on shaded side due to more auxins
46
Q

What do auxins do in the shoots?

What do auxins do in the roots?

A
Shoots = auxins make cells longer 
Roots = auxins stop cells getting longer
47
Q

What would happen if the tip of a plant was covered?

why?

A

The plant would grow straight because the auxins aren’t being broken down

48
Q

Give an example of weed killer and the advantages and disadvantages of it

A

Agent orange weed killer

Advantages
- selective weed killers only kill weeds plants aren’t damaged

Disadvantages
- some weed killers kill any plant not good for farmers

49
Q

What chemical helps ripen fruit?

What are the advantages and disadvantages of this?

A

Ethene

Advantages
- Ethene helps to ripen fruit when they are cut from the tree

Disadvantages
- too much ethene will kill the fruit and ripen other plants when given off

50
Q

Give advantages and disadvantages of rooting powder

A

Advantages
- able to grow lots of new plants from small cuttings

Disadvantages
- too many roots will kill the plant