Nerves And Hormones

Question 1

What are nerves involved with?

Answer 1

Sensing and responding to changes in the environment (stimuli)

Question 2

The action of nerves is both…

Answer 2

Faster and shorter lived compared to the action hormones which don’t act as quickly and have longer lasting effects on the body

Question 3

What is a receptor?

Answer 3

Receives/detects the stimulus

Question 4

What is the coordinator?

Answer 4

Determines the response

Question 5

What is an effector?

Answer 5

Carries out the response

Question 6

What is the eye an example of?

Answer 6

An advanced receptor

Question 7

What does the eye contain?

Answer 7

A number of cell types that are sensitive to light

Question 8

What is the fluid at the front of the eye called?

Answer 8

Aqueous humour

Question 9

What is the fluid at the back of the eye called?

Answer 9

Vitreous humour

Question 10

What are these fluids needed for?

Answer 10

To provide support to the eyeball and to allow light to pass through the eye to the retina

Question 11

What is the iris?

Answer 11

The coloured part of the eye

Question 12

What types of muscle does the iris contain?

Answer 12

Radial muscles and circular muscles

Question 13

What is the risk of bright light?

Answer 13

Bright light can damage the cells of the retina leading to blindness

Question 14

What happens to the circular muscles on the action of the iris muscles in bright light?

Answer 14

They contract

Question 15

What happens to the radial muscles in the action of the iris muscles in bright light?

Answer 15

They relax

Question 16

What happens to the effect of the diameter of the pupil in bright light ?

Answer 16

It is decreased

Question 17

What is the amount of light entering the eye in bright light?

Answer 17

It is decreased

Question 18

What is the risk of dim light?

Answer 18

Low light level can result in not enough light reaching to form an image

Question 19

What happens to the circular muscles in dim light?

Answer 19

They relax

Question 20

What happens to the radial muscles in dim light?

Answer 20

Contract

Question 21

What is the effect on the pupil diameter?

Answer 21

It increased

Question 22

What happens to the amount of light entering the eye in dim light?

Answer 22

Increased

Question 23

How is light focused onto the retina?

Answer 23

By changing the shape of the lens

Question 24

What are nerve cells specially adapted to do?

Answer 24

Carry electrical impulses through the nervous system

Question 25

Why are nerve cells long length?

Answer 25

To carry impulses long distance

Question 26

What is an insulating sheath for in a nerve?

Answer 26

To allow rapid transmissions of impulses

Question 27

Why do nerve cells have branching ends?

Answer 27

To receive or pass impulses from or to many other nerve cells

Question 28

What are synapses?

Answer 28

Tiny gaps between nerve cells

Question 29

What is the function of synapses?

Answer 29

For impulses to pass from one nerve cell to the next transmitter chemical must diffuse across the synapse at a high enough concentration to trigger an impulse in the next cell

Question 30

What happens when an impulse reaches a synapse?

Answer 30

1. The impulse reaches the synaptic bulb (end of the neurone)
2. Vesicles contains the transmitter move towards the cell membrane at the synapse
3. Vesicles release their neurotransmitter into the gap between the two cells
4. Neurotransmitter diffuses across the gap
5. The neurotransmitter reaches the membrane of the next cell
6. When enough neurotransmitter reaches the next cell an impulse will occur
7. The impulse travels along the next cell
8. The used neurotransmitter is broken down by an enzyme

Question 31

What is voluntary actions?

Answer 31

We have conscious control of the response

Question 32

What are reflex actions?

Answer 32

We are not conscious of these actions

Question 33

Reflex actions also tend to be much faster as they use a special pathway of nerves called the reflex arc that…..

Answer 33

Does away with thinking time