The nervous system

Some human responses are reflex actions.

Give two features of a reflex action.

Figure 3 shows the nerve pathway for moving a hand away from a sharp object.

Complete the sentences.

Choose answers from the box.

When the finger touches the sharp object, the point

Nerve impulses reach the arm muscle which is the

P, Q and R in Figure 3 are three types of neurone.

Draw one line from each letter to the type of neurone.

The gap between two neurones is called a synapse.

How does information travel across the synapse?

Tick (✓) one box.

Two students investigated reaction time.

This is the method used.

1. Student A holds a metre rule just above student B ’s hand, as shown in Figure 4.

2. Student A lets go of the metre rule.

3. Student B catches the metre rule as quickly as possible.

4. Student A writes down the reading from the scale on the metre rule.

5. Students A and B repeat steps 1 to 4 two more times.

Table 1 shows the results.

Calculate mean value X in Table 1.

The students concluded:

‘Practice improved the speed of student B ’s reaction.’

Give evidence for the students’ conclusion.

Use Table 1.

Suggest one way to improve the investigation.

Two students investigated reaction time.

This is the method used.

1. Student A holds a metre rule just above student B ’s hand, as shown in Figure 7.

2. Student A lets go of the metre rule.

3. Student B catches the metre rule as quickly as possible.

4. Student A writes down the reading from the scale on the metre rule.

5. Students A and B repeat steps 1 to 4 another six times.

Table 3 shows the results.

What is the median result in Table 3 ?

Tick () one box.

Calculate student B ’s mean reaction time.

Use the equation:

Give your answer in milliseconds.

Give your answer to 3 significant figures.

Use data from Table 3.

The method and Figure 7 are repeated below.

1. Student A holds a metre rule just above student B ’s hand, as shown in Figure 7.

2. Student A lets go of the metre rule.

3. Student B catches the metre rule as quickly as possible.

4. Student A writes down the reading from the scale on the metre rule.

5. Students A and B repeat steps 1 to 4 another six times.

Describe two ways the students could improve the investigation.

Do not refer to repeating results in your answer.

Catching the rule was a response to a stimulus.

Describe how student B ’s response was coordinated by the nervous system.

The nervous system allows humans to:

• respond to stimuli

• coordinate their behaviour.

Complete the order of structures to link a stimulus to a response.

Choose answers from the box.

Some human actions are reflex actions.

What is a reflex action?

Which is an example of a reflex action?

Tick (✓) one box.

Many reflex actions are movements.

What type of tissue causes movement?

Tick (✓) one box.

Many human activities are coordinated by the brain.

Figure 1 shows the human brain.

Which structure in Figure 1 is the pituitary gland?

Tick (✓) one box.

Which structure in Figure 1 is the cerebral cortex?

Tick (✓) one box.

What is the function of the cerebellum?

Tick (✓) one box.

The human body has two coordination systems:

• the nervous system

• the endocrine system.

Two students investigated human reaction time.

Student A held a metre rule above student B ’s hand.

Student A then released the metre rule and student B caught the rule as quickly as possible.

Figure 8 shows the method used.

Suggest two ways to improve the students’ method for measuring human reaction time.

Student B ’s reaction is coordinated by the nervous system.

Give two ways that coordination by the endocrine system is different from coordination by the nervous system.

Figure 9 shows endocrine glands in a female.

Name one hormone produced by gland A.

Name one hormone produced by gland B.

The adrenal gland produces the hormone adrenaline.

Describe two effects of adrenaline on the human body.

Hormones can be used for controlling human reproduction.

Explain the use of hormones in:

• contraception

• the treatment of infertility.

A person’s eyes can focus on objects at different distances.

A person looks at a distant object.

The person then looks at a near object.

The person’s eyes make adjustments so that the near object forms a clear image.

Which term describes the adjustment of focus from the distant object to the near object?

Tick (✓) one box.

Figure 14 shows the eye.

Which structure in Figure 14 is where the image is focused?

Tick (✓) one box.

Which structure in Figure 14 is a muscle that contracts when focusing on a near object?

Tick (✓) one box.

What happens to the shape of the lens when focusing on a near object?

The eyes can function in dimly-lit areas and in brightly-lit areas.

The iris contains muscles.

Describe how muscles in the iris help the person to see clearly when moving from a dimly-lit area to a brightly-lit area.

It is important to be able to react quickly.

Many people think that drinking coffee decreases reaction time.

Plan an investigation to test the effect of drinking coffee on reaction time.

You should include:

• the test for reaction time that you would use

• how to make the investigation valid.

A person’s eyes can focus on objects at different distances. A person looks at a distant object. The person then looks at a near object. The person’s eyes make adjustments so that the near object forms a clear image.

Which term describes the adjustment of focus from the distant object to the near object? Tick (✓) one box.

Figure 3 shows the eye.

Which structure in Figure 3 is where the image is focused? Tick (✓) one box.

Which structure in Figure 3 is a muscle that contracts when focusing on a near object? Tick (✓) one box.

What happens to the shape of the lens when focusing on a near object?

The eyes can function in dimly-lit areas and in brightly-lit areas. The iris contains muscles. Describe how muscles in the iris help the person to see clearly when moving from a dimly-lit area to a brightly-lit area.

It is important to be able to react quickly. Many people think that drinking coffee decreases reaction time. Plan an investigation to test the effect of drinking coffee on reaction time. You should include:

• the test for reaction time that you would use

• how to make the investigation valid.

Many human actions are reflexes.

Which statement describes a reflex action? Tick (✓) one box.

Figure 3 shows the nerve pathway for a reflex action. The arrows show the direction of the nerve impulse.

Draw one line from each part of the nerve pathway to the name of that part. Use Figure 3.

Part of nerve pathway Name of part

Which two human actions are reflexes? Tick (✓) two boxes.

Students investigated their reaction times using a computer program.

Figure 4 shows a sequence of two screens in the computer program.

This is the method used.

1. Open the reaction time program.

2. When the screen turns from red to green, touch the screen as quickly as possible.

3. Record the reaction time shown on the screen.

4. Re-set to the red screen.

5. Repeat steps 2 to 4 four more times.

6. Repeat steps 1 to 5 for each student.

Table 1 shows the results.

Calculate mean value X in Table 1.

There is an anomalous result for student R. Draw a ring around the anomalous result in Table 1.

Give two factors that might affect a person’s reaction time.

The human eye can form images of objects that are at different distances away from the eye. Figure 7 is a diagram of the eye.

Label structures A, B and C on Figure 7.

Choose answers from the box.

The eye in Figure 7 is focused on a distant object.

If the eye then focuses on the words in a book, changes would occur in the eye. The light rays would be refracted more by the lens.

How does the lens refract the light more?

Tick (✓) one box.

Which two structures control the shape of the lens?

Tick (✓) two boxes.

To form a clear image, the light rays entering the eye must focus on one structure in the eye. Name the structure.

An insect flies near a person’s eye. The person blinks. This is a reflex action. Figure 8 shows the coordination system for this reflex action.

Complete Figure 8.

Choose answers from the box below. Write one word in each of boxes 2, 3 and 4 of Figure 8.

Reflex actions are coordinated by the nervous system.

What is meant by the term ‘reflex action’?

A woman’s hand accidentally touches a hot object. The woman moves her hand away rapidly. Describe how the woman’s nervous system coordinates the reflex action.

The endocrine system coordinates many internal functions of the body. Give three ways coordination by the endocrine system is different from coordination by the nervous system.

Describe how hormones control the menstrual cycle.

The nervous system allows a person to detect stimuli.

Draw one line from each stimulus to the sense organ that detects the stimulus.

Moving a hand away from a hot object is an example of a reflex action.

What is a reflex action?

A muscle in the arm moves the hand away from the hot object.

How does the arm muscle do this?

Tick (✓) one box.

Two students investigated the effect of drinking coffee on reaction time.

This is the method used.

1. Student A holds a metre rule just above student B ’s hand, as shown in Figure 1.

2. Student A lets go of the metre rule.

3. Student B catches the metre rule as quickly as possible.

4. Student A writes down the reading from the scale on the metre rule.

5. Students A and B repeat steps 1‒4 another four times.

6. Student B then drinks a cup of coffee.

7. After 15 minutes, students A and B repeat steps 1‒5.

Table 1 shows some of the results.

Figure 2 shows the results after drinking the coffee for tests 3, 4 and 5.

Complete Table 1.

Use results from Figure 2.

The students made the following conclusion:

‘Drinking coffee speeds up reactions.’

Give evidence from Table 1 to support the students’ conclusion.

The students’ conclusion may not be valid.

Suggest two improvements the students could make to their method.

Many human actions are reflexes.

Which two of the following are examples of reflex actions?

Tick two boxes.

Figure 12 shows how the size of the pupil of the human eye can change by reflex action.

Name one stimulus that would cause the pupil to change in size from A to B, as shown in Figure 12.

Structure Q causes the change in size of the pupil.

Name structure Q.

Describe how structure Q causes the change in the size of the pupil from A to B.

Figure 13 shows some structures involved in the coordination of a reflex action.

Describe how the structures shown in Figure 13 help to coordinate a reflex action.

Many human actions are reflexes.

Which two of the following are examples of reflex actions?

Tick two boxes.

Figure 1 shows how the size of the pupil of the human eye can change by reflex action.

Name one stimulus that would cause the pupil to change in size from A to B, as shown in Figure 1.

Structure Q causes the change in size of the pupil.

Name structure Q.

Describe how structure Q causes the change in the size of the pupil from A to B.

Figure 2 shows some structures involved in the coordination of a reflex action.

Describe how the structures shown in Figure 2 help to coordinate a reflex action.