The human nervous system

Question 1

Explain the process of the reflex arc

Answer 1

1. The receptor detects the stimulus
2. Electrical impulses are generated and they pass along the sensory neurone (the first neurone of the refelx arc
3. The electrical impulse reaches a synapse where neurotransmitters are generated and they diffuse along the synapse gap from an area of high to low concentration.
4. Then electrical impulses are generated and are transmitted along the relay neurone in the spinal chord in the Central Nervous System.
5. The electrical impulses travel to the motor neurone which is connected to an effector, a muscle which contracts/gland that secretes a hormone in response

Question 2

Name the different adaptations of a neurone

Answer 2

1. Has many drendites
2. Has a long axon
3. Has a fatty myeli sheath layer insulating axon

aslo has nucleus in the cell body

Question 3

What is the myelin sheath made out of?

Answer 3

Fatty layer

Question 4

What is the function of the myelin sheath?

Answer 4

The myelin sheath is a fatty layer which insulates the axon on the neurone.

This prevents the transmission of electrical energy to the surroundings, thus speeding up the transmission of electrical impulses along the neurone.

Question 5

Explain how electrical impulses are transmitted across a synapse

Answer 5

1. Electrical impulses travel along the neurone and aproach the axon terminal
2. At theaxon terminal, neurotrnasmitters are generated
3. These neurotransmitters diffuse along the synapse from an area of high to low concentration
4. The neurotransmitters bind to the dendrites of the next neurone
5. At the dendrites, an electrical impulse is generated and it travels along the new neurone.

Question 6

Where is the nucleus found in a neurone?

Answer 6

In the cell body

Question 7

Neurones have many
d_ _ _ _ _ _ _ _

fill in the blank

Answer 7

Neurones have many dendrites

Question 8

What is the gap between two neurones called?

Answer 8

The synapse

Question 9

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
cross the synapse by diffusion

fill in the blank

Answer 9

Neurotransmitters
cross the synapse by diffusion

Question 10

What is generated after the neurotransmitters bind to the dendrites on the next neurone?

Answer 10

Electrical impulses are generated

Question 11

Electrical impulses are transmitted through a what?

Answer 11

Neurone

Question 12

What two things is the sensory neurone connected to?

Answer 12

Relay neurone

Sensory receptors

Question 13

What two things are connected to the motor neurone?

Answer 13

Relay neurone

Effector

Question 14

What are the two things that effectors can be?

Answer 14

Muscle

Gland

Question 15

When stimulated, what happens to an effector if it is a muscle?

Answer 15

The muscle contracts

Question 16

When stimulated, what happens to an effector if it is a gland?

Answer 16

It secretes hormones

Question 17

Name the Receptor cells in the human body

Answer 17

1. Eyes (see)
2. Nose (smell)
3. Tongue (taste)
4. Ears (sound)
   5.Pain receptors in skin (touch)

Basically, the 5 SENSES

Question 18

What is a receptor cell stimulated by?

Answer 18

A stimulus

Question 19

Give an example of a stimulus

Answer 19

Heat

Question 20

What is immediately generated at receptor cells?

Answer 20

Electrical impulses

Question 21

What is the first neurone in the reflex arc?

Answer 21

The sensory neurone

Question 22

What is the second neurone of the reflex arc?

Answer 22

The relay neurone

Question 23

Where is the relay neurone found?

Answer 23

In the spinal chord in the Central Nervous System

Question 24

Do reflexes involve the brain?

Answer 24

No

Question 25

Are **reflexes rapid** or **slow**?

Answer 25

**Rapid**

Question 26

Are **reflexes consious** or **unconscious**

Answer 26

**Unconscious**

Question 27

What is the **final neurone** of the **reflex arc**?

Answer 27

The **motor neurone**

Question 28

Why is the **reflex arc** important?

Answer 28

The reflex arc birngs a **rapid** and **automatic** response to a **stimulus**. This is important as it helps us **avoid** **danger** or **harm**

Question 29

**What** is the **function** of the **relay neurone**?

Answer 29

**Transfers electrical impulses** from the **sensory neurone** to the **motor neurone**

Question 30

**What** is the **function** of the **sensory neurone**?

Answer 30

To **transmit electrical impulses** from the **receptor** to the **relay neurone**

Question 31

**What** is the **function** of the **motor neurone**?

Answer 31

To **transmit electrical impulses** from the **relay neurone** to the **effector**

Question 32

**What** is the **function** of the **effector**

Answer 32

The **effector** converts **electrical impulses** into an **action**, e.g. muscle contraction or hormone secretion