Nerves And Hormones

Question 1

What does the nervous system do?

Answer 1

It allows us to respond to changes in our environment by coordinating actions.

Question 2

What is a stimulus?

Answer 2

A change in the environment that you might need to react to.

Question 3

What detects stimuli?

Answer 3

Sense organs

Question 4

What are the five sense organs?

Answer 4

• Eyes
• Ears
• Nose
• Tongue
• Skin

Question 5

What is the Central Nervous System?

Answer 5

Where all information from receptors in the sense organs is sent and processed.

Question 6

What two things make up the CNS?

Answer 6

The brain and the spinal chord.

Question 7

Give two examples of effectors and how they can react to stimuli.

Answer 7

• Muscles can contract

* Glands secrete hormones

Question 8

What is a sensory neurone?

Answer 8

A neurone that carries electrical signals from the receptors to the CNS.

Question 9

What is a relay neurone?

Answer 9

A neurone that carries electrical signals between the sensory neurones and the motor neurones. They are found in the CNS.

Question 10

What is a motor neurone?

Answer 10

A neurone that carries electrical signals from the CNS to the effectors.

Question 11

What is the order of events when the body comes into contact with a stimulus?

Answer 11

Stimulus > Receptor > Sensory Neurones >CNS > Motor Neurones > Effector > Respone

Question 12

What is a synapse?

Answer 12

The connection between two neurones.

Question 13

How do electrical signals cross synapses?

Answer 13

The nerve signal is transferred as chemicals called neurotransmitters. They then trigger an electrical signal at the next neurone.

Question 14

What is a reflex?

Answer 14

A fast, automatic response to a stimulus that bypasses the brim completely to save time.

Question 15

What is the purpose of a reflex?

Answer 15

To save the body from coming to harm.

Question 16

Describe the reflex arc.

Answer 16

Stimulus > Receptor > Sensory Neurone > Relay Neurone > Motor Neurone > Effector > Reflex action

Question 17

What is homeostasis?

Answer 17

The maintenance of a constant internal environment.

Question 18

What controls all our metabolic reactions?

Answer 18

Enzymes

Question 19

At what temperature do enzymes work best at?

Answer 19

37 degrees

Question 20

Why is it important for the body to be kept at 37 degrees?

Answer 20

Else wise the enzymes in the body would denature and so not work properly.

Question 21

What part of the body controls the body’s temperature?

Answer 21

The thermoregulatory centre in the brain.

Question 22

What organ removes excess ions from the body?

Answer 22

The kidneys

Question 23

How can the body lose water?

Answer 23

• Sweat
• Exhalation
• Urination

Question 24

How is blood glucose controlled?

Answer 24

By being used to create energy or being stored as glycogen in the liver.

Question 25

What are hormones?

Answer 25

Chemical messengers which travel in the blood to activate target cells. They are generally slow acting and have long-lasting effects.

Question 26

What produces hormones?

Answer 26

Glands

Question 27

What works quicker: nerves or hormones?

Answer 27

Nerves

Question 28

What acts for a longer time: nerves or hormones?

Answer 28

Hormones

Question 29

Which acts on a more specific area: nerves or hormones?

Answer 29

Nerves

Question 30

What is the menstrual cycle?

Answer 30

The sequence of events in which a female releases an ovum and prepares the womb in case of fertilisation.

Question 31

What is Stage One of the menstrual cycle?

Answer 31

Bleeding begins as the uterus lining breaks down. Lasts roughly 4 days.

Question 32

What is Stage Two of the menstrual cycle?

Answer 32

The uterus lining builds up again. This usually takes ten days.

Question 33

What is Stage Three of the menstrual cycle?

Answer 33

The ovum is released on day 14.

Question 34

What is Stage Four of the menstrual cycle?

Answer 34

The wall is maintained for 14 days. If a fertilised ovum is not received, the lining breaks down on day 28.

Question 35

What does FSH stand for?

Answer 35

Follicle Stimulating Hormone

Question 36

Where is FSH produced?

Answer 36

The pituitary gland

Question 37

What does FSH do?

Answer 37

Causes the ovum to mature and stimulates the production of oestrogen.

Question 38

Where is oestrogen produced?

Answer 38

The ovaries

Question 39

What does oestrogen do?

Answer 39

Causes production of LH and prevents production of FSH.

Question 40

What does LH stand for?

Answer 40

Luteinising Hormone

Question 41

Where is LH produced?

Answer 41

The pituitary gland

Question 42

What does LH do?

Answer 42

Stimulates the release of the ovum.

Question 43

What is a contraceptive?

Answer 43

A method of preventing pregnancy.

Question 44

What two hormones can be used as contraceptives?

Answer 44

Oestrogen and Progesterone.

Question 45

How does oestrogen act as a contraceptive?

Answer 45

It inhibits FSH production.

Question 46

How does progesterone act as a contraceptive?

Answer 46

It stimulates the production of thick cervical mucus which prevents sperm from reaching the ovum.

Question 47

What does "the pill" contain?

Answer 47

Progesterone and oestrogen.

Question 48

Why did the oestrogen content of the pill have to be reduced?

Answer 48

Because links were made between the pill and blood clots.

Question 49

What are the benefits of taking the pill?

Answer 49

* 99% success rate | * Reduced risk of some cancers

Question 50

What are the problems with the pill?

Answer 50

* Not 100% effective * Some side effects (headaches, nausea etc) * Doesn't prevent STIs

Question 51

How can one increase fertility?

Answer 51

By injecting FSH and LH to stimulate egg maturation and release.

Question 52

What are the issues with injecting FSH and LH?

Answer 52

* Doesn't always work | * Can result in unexpected multiple pregnancies

Question 53

What does IVF stand for?

Answer 53

In Vitro Fertilisation

Question 54

What is IVF?

Answer 54

A process that can be used to help couples who are having difficulty having children.

Question 55

Describe the process of IVF

Answer 55

1) FSH and LH are used to stimulate the release of multiple ova 2) Ova are collected from the ovaries 3) The ova are fertilised in a lab using a sample of the father's sperm 4) The fertilised eggs are grown into embryos. One or two are replaced into the woman's uterus.

Question 56

What are the problems surrounding IVF?

Answer 56

* Some woman have strong negative reactions to the hormones * Links to cancer * Multiple births and related issues

Question 57

What is auxin?

Answer 57

A plant hormone found in the tips of roots and shoot. It encourages growth in shoots and inhibits growth in roots.

Question 58

What is phototropism?

Answer 58

Plant growth in respond to light.

Question 59

What is gravitropism?

Answer 59

Plant growth in response to gravity.

Question 60

What happens when a shoot tip is exposed to light?

Answer 60

More auxin accumulates at the shaded side of the shoot. This makes the cells on the shaded side grow quicker and so the shoot bends towards the light.

Question 61

What happens when a shoot is growing sideways?

Answer 61

Auxin falls to the bottom of the shoot which stimulates growth at the bottom of the shoot. This means the shoot bends upwards.

Question 62

What happens when a root grows sideways?

Answer 62

The auxin falls to the bottom which inhibits growth in the bottom of the root. This causes the root to bend downwards.

Question 63

What happens when there's more moisture on one side of a root?

Answer 63

Auxin moves to the moist side which inhibits growth on the moist side. This causes the root to bend towards the moisture.

Question 64

Name two ways artificial plant hormones are used in agri- /horticulture.

Answer 64

* Selective weed killers | * Rooting powders

Question 65

How do selective weed killers work?

Answer 65

They are made of plant growth hormones that only work on broadleaved plants. This disrupts the broadleaved weeds' growing patterns so they die.