Nervous Pathways

Question 1

How are neurones classified?

Answer 1

1. By direction of action potential
2. Route by which information travels
3. Effect on target neurones

Question 2

What are afferent neurones?

Answer 2

Convey information from tissues and organs to brain (CNS)

Question 3

What are sensory neurones an example of?

Answer 3

Afferent neurones

Question 4

What are efferent neurones?

Answer 4

Transmit information from brain (CNS) to effector cells in body

Question 5

What are motor neurones an example of? Where do their cell bodies lie?

Answer 5

Efferent neurones

Cell bodies lie in CNS (long axon projects into PNS and innervates target organ - skeletal muscle)

Question 6

What types of neurones does somatic nervous system contain?

Answer 6

1. Sensory afferent fibres

2. Motor efferent neurones

Question 7

Function of sensory afferent fibres in somatic nervous system?

Answer 7

1. Receive information from external stimuli

2. Carry information to CNS for processing

Question 8

Function of motor efferent neurones in somatic system?

Answer 8

1. Processed information sent back via efferent nerves from CNS back through somatic system
2. Instructions go to neuromuscular junction for motor output

Question 9

Where are sensory endings / terminals of sensory afferent fibres?

Answer 9

In target organ / in CNS

Question 10

Function of sympathetic system?

Answer 10

Speed things up - ‘fight, flight or freeze’

Has efferent (motor) and afferent (sensory) components

Question 11

Function of parasympathetic system?

Answer 11

Calm things down - ‘rest and digest’

Has efferent (motor) and afferent (sensory) components

Question 12

What is a neurotransmitter?

Answer 12

Released by neurone, binds to chemical receptors on target neurone

Combination of receptor and neurone results in:
1. Excitatory
2. Inhibitory
3. Modulatory 
change to target neurone

Question 13

What are 2 most common neurotransmitters in brain?

Answer 13

GABA and glutamate (have opposing actions)

Question 14

What is effect of glutamate?

Answer 14

Largely excitable effects

Question 15

What is effect of GABA?

Answer 15

Inhibitory effects

Question 16

What do excitatory neurones in spinal cord release?

Answer 16

Acetylcholine

Question 17

What do inhibitory spinal neurones release?

Answer 17

Glycine

Question 18

What does the motor neurone pathway comprise from CNS to target tissue?

Answer 18

2-neurone link (preganglionic and postganglionic neurone)

Question 19

Describe preganglionic fibre of:

1. Parasympathetic system
2. Sympathetic system

Answer 19

1. Long, myelinated

2. Short, myelinated (short distance to sympathetic chain)

Question 20

Describe postganglionic fibre of:

1. Parasympathetic system
2. Sympathetic system

Answer 20

1. Short, few branches

2. Long, many branches

Question 21

Describe ganglia of:

1. Parasympathetic system
2. Sympathetic system

Answer 21

1. Near or in target tissue

2. Close to spinal cord

Question 22

Give preganglionic transmitter of:

1. Parasympathetic system
2. Sympathetic system

Answer 22

1. Acetylcholine

2. Acetylcholine

Question 23

Give postganglionic transmitter of:

1. Parasympathetic system
2. Sympathetic system

Answer 23

1. Acetylcholine

2. Noradrenaline