§3.5 The spinal cord [Topic 3 - organizing the world]- Year 2

• Science
• Middelbare school
• havo, vwo
• Leerjaar 2

GET READY

ONLY YOUR MACBOOK:

KWIZL - YR2_T3.5

YR2_3.5

Do the quiz.

Check another quiz and give feedback.

Reflect upon your own work.

(write this down in your notebook)

Get ready

- TB p. 142

- notebook

- this lessonup

Topic 3

ORGANIZING THE WORLD

§3.5 The Spinal Cord

p. 142-143

§3.5  - Learning goals

I can....

• explain how reflexes are different than a normal nervous system response.
• follow the chain of events that take place during a reflex arc.
• explain how impulses are passed from one neuron to the next.
• explain the function of neurotransmitters in spreading impulses.
• describe how drugs can connect to receptors and disturb impulses.

p. 142-143

§3.5  - Key words

• Reflexes 
• Spinal cord
• Synapses
• Vesicles
• Neurotransmitters

p. 142-143

Spinal cord

The nerves connect the central nervous system to all parts of the body.

Impulses are passed to the brain through nerves in the spinal cord. The spinal cord starts at the brain and ends in the lumbar vertebrae in the lower back. 

Spinal cord

Vertebra

Nerve

§3.5  - Reflexes

A reflex is also a response of your body, but then using your spinal cord as a coordinator instead of a your brain:

- this is often used in cases of emergency

p. 142-143

Reflex arcs

•  Why do you think a reflex is unconscious? 

• Impulses do not go to the brain immediately

• They go to the spinal cord and back (short circuit) 

Reflex arcs

W

1. Stimulus= 

2. Receptor= 

3. Effector= 

4. Response= 

Reflex arcs

1. Stimulus = hot flame     2. Receptor = heat sensor in the skin 

3. Effector = muscles in your arm 

4. Response = moving your hand away from the hot object. 

How do reflexes work?

• Reflexes are involuntary.
  
• Don’t ‘think’ about them: it just happens
  
• So fast they don’t go to the brain!
  
• Controlled by the spinal cord.
  

Refelex arc

warmth from the flame –> sensory receptors of the skin –> impulses by sensory neurones –> impulses by interneurons in spinal cord –> impulses by motor neurons -> muscles in the arm contract

Without knowing you raised your arm!

Reflex arc: diagram

§3.5  - Synapses

Synapses are connections in your nervous system that use chemicals in stead of electricity:

- synapses work with a chemical called neurotransmitters

- the bag that holds the neurotransmitter is called a vessicle

p. 142-143

HW for next time:

If possible: have the exercises of §3.5 finished.

REVIEW LESSON: 60 min

a quick review of all topics

a chance to ask questions and extra explanations

a practice test, feedback & reflection

p. 142-151