Coordination and Response (Nerve System)

Question 1

What are neurons and its function?

Answer 1

Long, thin fibers of cytoplasm stretch out from the cell body to coordinate messages passed through the nervous system.

Question 2

What fibre can be a metres long?

Answer 2

An axon

Question 3

How are nerve impulses picked up?

Answer 3

The dendrites pick up signals that passes through the cell body, to the axon.

Question 4

What are the two different nervous systems?

Answer 4

Central Nervous System (CNS) and Peripheral Nervous System (PNS)

Question 5

What are both CNS and PNS made up of?

Answer 5

1. CNS: Spinal cord and brain
2. PNS: Nerves and receptors

Question 6

What does the brain/spinal cord do?

Answer 6

When a receptor detects a stimulus, it sends an electrical signal to the brain or spinal cord, where they send an impulse along to the effectors.

Question 7

Describe the reflex arc

Answer 7

The receptor-sensory neuron - relay neuron (delivery) - motor neuron - and effector

Question 8

How does the synapse ensure the nerve impulses only travel in one direction?

Answer 8

When an impulse arrives along the axon of a sensory neuron, it causes these vesicles to move and empty their contents to the cell membrane of the synaptic cleft.

The neurotransmitter diffuses across the tiny gap and attaches receptor molecules to the relay neuron. This can happen because the shape of the neurotransmitter compliments the shape of the receptor molecules.

The binding of the neurotransmitter with the relay neuron creates a nerve impulse that sweeps away to the next synapse. A similar process occurs when passing on nerve impulses to the motor neuron.

This ensures the nerve impulse to travel one way because there is only neurotransmitter on one side of the synapse.