Chapter 14: Coordination and response

Question 1

What makes up the mammalian nervous system?

Answer 1

The central nervous system (CNS): consists of the brain and spinal cord
The peripheral nervous system (PNS): consists of the nerves outside of the brain and spinal cord

Question 2

What is the role of the nervous system?

Answer 2

Coordinate electrical impulses travelling through the nervous system, and regulate body functions

Question 3

What are the structures of sensory, relay, and motor neurones?

Answer 3

Sensory: cell body in the middle, long dendrites and long axons branching out
Relay/interneurone: short dendrites and short axons
Motor: short dendrites, long axon

Question 4

What is a simple reflex arc?

Answer 4

A series of neurones (sensory neurone, relay/interneurone, motor neurone) that transmit electrical impulses from a receptor to an effector

Question 5

Define ‘reflex action’

Answer 5

A means of automatically and rapidly integrating and coordinating stimuli with the responses of effectors, muscles and glands

Question 6

Define ‘synapse’

Answer 6

A junction between 2 neurones

Question 7

What is the structure of a synapse?

Answer 7

Synaptic vesicles, which contain neurotransmitters, are present on the axon terminal. The gap between the axon and the dendrite is known as the synaptic gap, and receptor proteins are present on the membrane of the dendrite

Question 8

What happens at a synapse?

Answer 8

A nerve impulse arrives at the axon terminal, stimulating the release of neurotransmitters from the vesicles into the synaptic gap. The neurotransmitters diffuse across the synapse and bind with the receptor proteins on the membrane of the dendrite, stimulating it to generate a nerve impulse

Question 9

What is the importance of synapses?

Answer 9

They ensure that impulses travel in one direction only