HomeoStasis: Nervous system.

Question 1

What 2 parts does the nervous system consist of?

Answer 1

• Central nervous system (Brain and Spinal Cord).

- Nerves running 2 and from the CNS.

Question 2

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Answer 2

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Question 3

What is the reflex arc? (when you touch a hot object)

Answer 3

1) Stimulus is detected by a receptor.
Stimulus = heat receptor= skin.
2) Electrical impulses now pass from the receptor along the sensory nueron to the CNS.
Synapse: At the end of the sensory neuron is a junction called a synapse. At the synapse a chemical is released. Chemical diffuses across to the relay neuron in the CNS and triggers an electrical impulse.
Relay Neuron: Electrical impulses passes across the relay neuron and reaches another synapse. Chemical is released and the chemical triggers and electrical impulse in a motor neuron.

Eletrical impulse passes through the motor neuron and to an effector.
Muscle contracts and pulls hand away from heat- Response.

Question 4

What is a reflex?

Answer 4

• No descision making by the concious part of the brain.
• Automatic and rapid.
  As they are rapid reflexes help protect us from danger.