5.4 The nervous system part 3

• Biologie
• Middelbare school
• vwo
• Leerjaar 1

Bs 4: The nervous system part 2

Planning for today

•  Look back at last class
•  Bs 4. nerve cells/nerves and reflexes
• Test your reflexes

Learning goals

• 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. 
• You must be able to tell what reflexes are and how they work.

Senses of humans

Path taken by nerve impulses

notes:

2 types of pathways

  1. Conscious reaction - voluntary response, example: girl and   chocolate -> impuls goes to brain.

  2. Reflex - involuntary response, impulse does not go to the     brain but stays within the CNS

 example: withdrawal reflex = hand touches fire 

How does the nervous system work

Notes:

Sensory cell receive stimulus from outside (ex. chocolate)

Sensory cells                                                                                                                         = impulses                            =   nerves   

     brain    

 muscles

Nerve cell

Structure of the nerve cell 

Notes:

1. Cell body - located in or near the CNS

2. Axon - conducts (vervoert) impulses to and from cell body

What is a nerve?

Notes: 

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

Reflexes

Notes

A reflex is a fixed, fast and involuntary reaction to a certain stimulus.

In a reflex, the impulses do not go through your brain first (except for reflexes that take place in your head)

Why does this happen?

Test your reflexes

* Make groups of 2 or 3 people

* Go to your studiewijzer and open the document: Werkblad reflexen 

* Do al 3 of the exercises to test your reflexes!