Topic 5a: Homeostasis and Response: The Nervous System

Question 1

5a1

Question 2

Define homeostasis

Answer 2

The regulation of conditions
Inside your body (and cells)
To maintain a stable internal environment
In response to
Changes in both internal and external conditions

Question 3

What are 3 internal conditions that need regulation?

Answer 3

Blood glucose concentration
Body temp
Water levels (in the blood and tissue fluids)

Question 4

Name the way that internal conditions are regulated

Answer 4

Automatic / involuntary control systems

Question 5

What 3 main components work together to maintain a steady condition?

Answer 5

Receptors
Coordination centres
Effectors

Question 6

Name an example of a coordination centre

Answer 6

Brain
Spinal cord
Pancreas

Question 7

What are the effectors of the body

Answer 7

Muscles
Glands

Question 8

What are responsible for maintaining a stable internal environment

Answer 8

Nervous system and hormones

Question 9

What is the solution surrounding red blood cells when travelling thorough veins

Answer 9

Plasma

Question 10

Define stimulus

Answer 10

A change in your environment that you might need to respond to

Question 11

Give an example of a stimulus

Answer 11

Light, sound, touch, pressure, pain, chemical, or a change in position or temperature

Question 12

Define a negative feedback mechanism

Answer 12

The mechanism that restores the optimum level

Question 13

The mechanism that restores the optimum level is called the…

Answer 13

Negative feedback mechanism

Question 14

What is the main risk of the negative feedback mechanism?

Answer 14

The effectors could just carry on producing the responses
Making the level change too much

Question 15

What is the purpose of the nervous system?

Answer 15

Allows you to react to your surroundings
And allows you to coordinate your behaviour

Question 16

Define a receptor

Answer 16

Cells that detect a stimuli aka a change in the environment

Question 17

Define a coordination centre

Answer 17

They receive information from the receptors, process the info and instigate a response

Question 18

Define an effector

Answer 18

Are muscles or glands which respond to nerve impulses and bring about a response to a stimulus

Question 19

How do muscles respond to stimuli

Answer 19

They contract

Question 20

How do glands respond to stimuli

Answer 20

Secrete chemical substances called hormones

Question 21

State an example of a receptor

Answer 21

Taste receptors on the tongue
Sound receptors in the ears
Smell receptors in the nose
Light receptors in the eyes

Question 22

Define a sensory neurone

Answer 22

The neurones that carry information
As electrical impulses
From the receptors
In the sense organs
To the central nervous system

Question 23

Define a relay neurone

Answer 23

The neurones that carry electrical impulses
From sensory neurones
To motor neurones
They are found in the cns

Question 24

Define a motor neurone

Answer 24

The neurones that carry electrical impulses
From the cns to the effectors

Question 25

State the transmission of information to and from the cns (flow diagram)

Answer 25

Stimulus —> Receptors—> Sensory neurone —> Relay neurone (cns/coordinator) —> Motor neurone —> Effector —> Response

Question 26

Define a synapse

Answer 26

The connection between two neurones

Question 27

How are nerve signals transferred across synapses?

Answer 27

The signal is transferred by chemicals which diffuse across the gap
These chemicals set off a new electrical signal in the next neurone

Question 28

Define a reflex

Answer 28

Fast automatic responses to certain stimuli

Question 29

Give an example of a reflex

Answer 29

Pupil contraction when confronted with light
Adrenaline when confronted with shock
Knee jerk reflex

Question 30

Describe the reflex of pupil contraction

Answer 30

If someone shines a bright light in your eyes
Your pupils automatically get smaller
So that less light gets into your eyes
Which stops them from getting damaged

Question 31

Define a neurone

Answer 31

Nerve cell
Adapted to carry electrical impulses from one place to another

Question 32

What is a nerve cell called

Answer 32

Neurone

Question 33

What is the name for a bundle of neurones?

Answer 33

Nerve

Question 34

Define a nerve

Answer 34

Bundle of neurones
Blood supply to provide oxygen and glucose