Form 3 Chapter 1.1 Human Nervous System

Which parts stated below are the central nervous system?

• spinal nerves

• brain

• spinal cord

• cranial nerves

Answer explanation

Which parts stated below are the peripheral nervous system?

• spinal nerves

• brain

• spinal cord

• cranial nerves

Answer explanation

Voluntary actions are:

• conscious actions and conducted under one’s will

• actions that occur immediately without conscious control

• controlled by the brain

• controlled by the medulla oblongata or spinal cord

Answer explanation

Examples of voluntary actions: reading, writing, speaking, eating, drinking, walking, running and exercising

Which part controls involuntary actions such as heartbeat, breathing and peristalsis?

• Medulla oblongata

• Spinal cord

Answer explanation

There are TWO types of involuntary actions.

The spinal cord controls involuntary actions known as reflex actions.

Choose the correct examples of reflex action:

• Withdrawing hand when it accidentally touches a hot object

• Secretion of saliva

• Withdrawing foot when it accidentally steps on a sharp object

• Peristalsis

• Sneezing when dust enters the nose

Answer explanation

Reflex actions are immediate actions controlled by the spinal cord (not brain).

These actions protect a person from injury.

The ___________ detects stimuli from the surroundings and converts them to nervous impulses.

Answer explanation

Nervous impulses are electrical signals that can travel along the nerve cells (nerves/neurons).

Tags

NGSS.MS-LS1-8

The image shows the pathway of a nervous impulse in an action. Give two examples of the action involved.

(hint: voluntary action or involuntary action)

• Writing

• Breathing

• Peristalsis

• Withdrawing foot when it accidentally steps on a sharp object

• Walking

Answer explanation

Voluntary actions involve the brain but involuntary actions involve the spinal cord.

Changes in the size of the pupil is an involuntary action.

When entering a darker room, the pupil becomes ___________ so that more light can enter the eyes.

The following are structures involved when touching a hot object.

Which of the following pathways is correct?

• N, M, L, J, K

• L, K, J, M, N

• L, M, J, K, N

• M, N, J, L, K

Answer explanation

The responses of human can be divided into two: Voluntary actions and involuntary actions.
Match the examples of actions based on which part that controls them.

Groups:

(a) Medulla oblongata

,

(b) Spinal cord

,

(c) Brain

• Singing

• Withdrawing hand quickly when accidentally touching a hot object

• Dancing

• Breathing

• Thinking

• Sneezing when dust enters the nose

• Heartbeat

• Reading

• Knee-jerk reaction

•