B - The nervous system

• Biologie
• Middelbare school
• havo, vwo
• Leerjaar 1

Today's planning

1. Repeat basic A

2. Basic B the nervous system

Repeat A

Senses, coordination and behaviour

What happens in the image on the left?

What is the adequate stimulus for the sense of seeing?

What does a sensory cell produce once it picks up a stimulus?

What do we call the lowest intensity that can cause an impuls?

1. Adequate stimulus
2. Threshold value
3. impuls
4. habituation

If a stimulus does not go away for some time, it starts producing less impulses in the cell. What do we call this?

1. Adequate stimulus
2. Threshold value
3. impuls
4. habituation

BS B - The nervous system

• You must be able to name the functions of the nervous system. 
• You must be able to describe the structure of a nerve cell and a nerve. 
• You must be able describe the three types of nerve cells. 

Structure of the nervous system

1. Central nervous system (CNS) = Brain and spinal cord

2. Nerves

How does the nervous system work?

Path taken by nerve impulses

2 types of pathways:

  1. Voluntary response - conscious reaction (bewust), impulse goes to the brain and then to the muscles or glands.

example: girl and eating of the chocolate

  2. Involuntary response (also called a reflex) - non-conscious (onbewust), impulse does not go to the brain, but goes directly to the muscle. 

example: withdrawal reflex = hand touches fire 

Nerve cell

Structure of the nerve cell 

Notes:

1. Cell body - located near the CNS

2. Axon - transports impulses to and from cell body

3 types of nerve cells

notes: 

1. Sensory neurons: pass the impulses from the sense organs to the CNS

2. Motor neurons: pass impulses from the CNS to the muscle/glands

3. Interneurons: conduct impulses within the CNS

What is a nerve?

Notes: 

nerve = a bundle of axons of nerve cells surrounded by a tough, protective layer

Motor neuron

Interneuron

Sensory neuron

carries impulses inside the central nervous system

carries impulses from central nervous system to muscles or glands

receives impulses from sensory neurons or interneurons

Receives impulses from interneurons

receives impulses from sensory cells

brings impulses to the central nervous system

Make the worksheet in studiewijzer

You may work alone or in pairs. 

If you work together, you both fill in the worksheet.

B - The nervous system

Do the assignments 1 to 4

Homework: worksheet nerves & nerve cells

• You must be able to name the functions of the nervous system. 
• You must be able to describe the structure of a nerve cell and a nerve. 
• You must be able describe the three types of nerve cells.