B1- Nervous System Flashcards Preview

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Flashcards in B1- Nervous System Deck (9)
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1

What does the nervous system do

Enables humans to react to their surroundings

2

What are receptors

Cells that detect stimuli (changes in the environment)

3

Examples of receptors and the stimuli they detect

Receptors in eye are sensitive to light

Receptors in ears are sensitive to sound

Receptors on tongue and nose are sensitive to chemicals that let us taste and smell

Receptors in skin are sensitive to touch, pressure pain and temp change

4

What do light receptors contain

Nucleus
Cytoplasm
Cell membrane

5

Role of sensory neurones

Carries signals from receptors to spinal cord and brain

6

Role of motor neurone

Carries signals from CNS to effectors

7

Role of relay neurones

Carry message from CNS to another

8

Role of synapses

Gap where two neurones meet

9

What happens in a reflex action

Impulse passes along a sensory neurones to the CNS
Impulse reaches synapse between sensory neurones and relay
Chemical released at synapse causing impulse to be sent along neurone
Chemical releases between relay and motor neurone. Triggers impulse to pass down to motor neurone
Impulse reaches effector (muscle or gland) which contracts leading to response