Lesson 2: Synapses & reflexes

• Biologie
• Middelbare school
• vwo
• Leerjaar 2

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• Lesson 2 synapses and reflexes
• Lab report respiration grades and feedback
• Knowledge quiz 

Brain and Senses

Lesson 2: Synapses & reflexes

Chapter 8: Kerboodle:  'Control and coordination' 

-Page 112-114

Dendrite

Cell body

Nucleus

Axon

Fatty sheath

Synapse

Synapses 

• Gap between 2 neurons
• When an impulse reaches the end of the axon it produces  a chemical: neurotransmitters
• Diffuses across the gap and binds receptors of in the membrane of the next neuron
• It starts off a impulse in the next neuron
• One end can make it so impulses travel in one direction!

Impulse

Impulse

Synapses 

2 other functions:

• Resistor: enough impulses are needed to start an impulse at the next neuron. 
• Junction box: a neuron can pass an impulse to a number of neurons

Drugs affect synapses

• Alchohol (slows reactions down)

Impulse

Impulse

Synapse at the muscle

Reflex arcs

• You take away your hand from an hot object very fast
  Automatically, why? 
  
  
• Reflexes protect you 
• Why do you think a reflex is unconscious? 
  
  
• Signal does not go to the brain immediately
• It goes to the spinal cord and back (short circuit) 

Reflex arcs

W

Stimulus? 

Receptor? 

Effector? 

Response? 

Reflex arcs

Stimulus = hot flame 

Receptor = heat sensor in the skin 

Effector = muscles in your arm

Response = moving your hand away from the hot object. 

Lab report respiration

-Look at the feedback

-Ask questions if you have them

HW for next lesson 

Hw for lesson 4: 

Complete the worksheet on classroom