Homeostasis and the nervous system

Question 1

Maintaining the correct conditions in the body for it to function correctly is known as?

Answer 1

Homeostasis

Question 2

State the three key conditions in the body controlled by homeostasis

Answer 2

1 Body temperature
2. Blood glucose concentration
3. Water balance

Question 3

What is homeostasis?

Answer 3

Maintaining the correct conditions in the body for it to function correctly

Question 4

Much of the automatic involuntary regulation of homeostasis in the body is made by two body systems, identify them.

Answer 4

1. nervous system- sending nerve impulses
2. endocrine system- producing hormones

Question 5

There are 3 key parts to the nervous system - identify them

Answer 5

1. Receptor
2. Central nervous system
   3 Effector

Question 6

Describe the role of an effector in the nervous system

Answer 6

An effector causes a response by either moving the body or secreting a hormone

Question 7

Describe the role of an receptor in the nervous system

Answer 7

They detect changes inside or outside of the body and respond by generating an electrical response.

Question 8

Describe the role of the central nervous system

Answer 8

Receives impulses from the receptors and coordinates a response by sending impulses to the effectors.

Question 9

What makes up the Central nervous system (CNS)

Answer 9

The brain and the spinal cord

Question 10

How are messages transmitted along nerve cells

Answer 10

by electrical impulses

Question 11

What is the role of the myelin sheath around a long nerve cell

Answer 11

It insulates the cell allowing faster electrical impulses up to 250mph

Question 12

Identify the 5 sense organs

Answer 12

Eyes
Ears
Nose
Tongue
Skin

Question 13

What stimuli do we receive in order to see

Answer 13

Light waves

Question 14

What stimuli do we receive in order to hear

Answer 14

Sound waves

Question 15

What stimuli do we receive in order to taste

Answer 15

Chemicals in food

Question 16

What stimuli do we receive in order to smell

Answer 16

Chemicals diffusing through the air

Question 17

What stimuli do we receive in order to touch

Answer 17

pressure, itching, pain and temperature

Question 18

Identify the three types of neurone

Answer 18

Sensory, motor and relay

Question 19

What are nerves comprised of?

Answer 19

Bundles of neurones

Question 20

Describe the role of a sensory neurone

Answer 20

One which carries a nerve impulse from a receptor towards the CNS

Question 21

Describe the role of a relay neurone

Answer 21

One which carries a nerve impulse within the CNS, the brain and spinal cord

Question 22

Describe the role of a motor neurone

Answer 22

One which carries a nerve impulse from the CNS to an effector (muscle or gland)

Question 23

Describe the pathway through the nervous system from receiving a stimulus to responding to it.

Answer 23

Stimulus –> receptor –> sensory neurone –> relay neurone –> motor neurone –> effector –> response

Question 24

What is a dendrite?

Answer 24

The branched beginnings of a neurone which detect the chemical neurotransmitters and start another electrical impulse

Question 25

What is a synapse?

Answer 25

The gap between the axon of one nerve and the dendrites of another

Question 26

What is an axon?

Answer 26

A nerve fibre which conducts electrical signals called impulses

Question 27

What happens to a nerve impulse when it reaches a synapse?

Answer 27

The electrical signal spreads out at the end of axon into the root like ends of the cell. At the tips of these the electrical impulses are converted into chemical signals called neurotransmitters. These diffuse across the synapse and bind to receptors in the dendrites of the next neurone. It triggers an electrical impulse which travels along the neurone until it reaches the next synapse and so on.

Question 28

What is a reflex response

Answer 28

It is a rapid automatic response to a stimulus such as pain or heat which does not reach the brain. Other reflex responses include regulating heart rate and dilating or contracting the pupil to let light into your eyes.

Question 29

How is the reflux arc when you touch something very hot different from other neural pathways

Answer 29

The pathway of neurones in the reflex arc does not include relay neurones immediately transmitting information to the brain. Instead when a sensory neurone transmits a pain stimulus to a relay neurone in the spinal cord it first sends an impulse along the motor neurone to the muscle effector to move away from the heat.

Question 30

What is the difference between a reflex action and a conscious decision?

Answer 30

Conscious decisions involve relay neurones in the brain before motor neurones send impulses to the effectors wheras reflex actions are automatic and the signal is generated from the spinal cord.