Lecture 17: Integrating and Coordinating Roles of the Nervous System

Question 1

What do afferent and efferent mean?

Answer 1

Afferent is information moving into the CNS from the PNS, efferent is information moving out from the CNS to the PNS.

Question 2

What does the PNS and CNS each consist of?

Answer 2

CNS: Brain and spinal cord.
PNS: Cranial nerves and spinal nerves.

Question 3

What is somatic and autonomic?

Answer 3

Somatic = things we have conscious control over. 
Autonomic = things we have no conscious control over, are not aware of.

Question 4

What four types of information transmitted in the nervous system?

Answer 4

Somatic sensory, somatic motor, visceral sensory (afferent), and autonomic motor (efferent).

Question 5

How many neurons between CNS and effector?

Answer 5

1

Question 6

Where is the cell body and axon of a somatic motor neuron?

Answer 6

Cell body in spinal cord (CNS) and axon in spinal nerves (PNS). Often very long.

Question 7

What are the effectors of a somatic motor neuron?

Answer 7

Skeletal muscle fibres.

Question 8

What neurotransmitter is released at the synapse of a somatic motor neuron? What is this synapse called?

Answer 8

Acetylcholine (ACh)

Neuromuscular junction.

Question 9

What is a motor unit?

Answer 9

A motor neuron and all the muscle fibres it innervates.

Question 10

Are muscle cells ever innervated by more than one neuron?

Answer 10

No.

Question 11

Is the axon myelinated in somatic motor division nerves?

Answer 11

Yes!

Question 12

Where are nerves in the Autonomic Nervous System?

Answer 12

Neuron #1 has cell body in CNS and axon in the PNS. This connects to neuron #2 which has its cell body and axon in the PNS.

Question 13

What are the effectors of the autonomic nervous system?

Answer 13

Smooth Muscle, Cardiac Muscle, Glands, Adipose(fat) Tissue

Question 14

Where do neurons in the autonomic system synapse and what neurotransmitter do they release?

Answer 14

Neuron #1 (pre-ganglionic) synapses in the Autonomic Ganglion and releases acetylcholine. Neuron #2 (post-ganglionic) synapses on the effector organ and releases either acetylcholine (ACh) OR noradrenaline (NE)

Question 15

What division of the nervous system are the sympathetic and parasympathetic subdivisions part of?

Answer 15

Autonomic

Question 16

What is the sympathetic nervous subdivision?

Answer 16

Sympathetic: “FIGHT OR FLIGHT”. Increased heart rate, blood flow to muscles, pupil size and sweating. Decreased blood flow to skin and viscera, salivation, and gastric motility.

Question 17

What is the parasympathetic nervous subdivision?

Answer 17

Parasympathetic: “REST & DIGEST”.

Increased gastric motility and salivation, decreased pupil size and heart rate.

Question 18

What do sympathetic nerves synapse on and what neurotransmitter do they release?

Answer 18

The pre-ganglionic neuron has a short axon, synapses at the sympathetic ganglion (sympathetic chain ganglia, close to the CNS) and releases ACh. The post-ganglionic neuron has a long axon, synapses with the effector and releases NE.

Question 19

What do parasympathetic nerves synapse on and what neurotransmitter do they release?

Answer 19

The pre-ganglionic neuron has a long axon, synapses at the parasympathetic ganglion (far from the CNS) and releases ACh. The post-ganglionic neuron has a short axon, synapses with the effector and releases ACh.

Question 20

Which axons are myelinated in the parasympathetic and sympathetic nervous systems?

Answer 20

The pre-ganglionic axon.

Question 21

Where do axons of sympathetic pre-ganglionic neurons leave the CNS?

Answer 21

At thoracolumbar levels (spinal cord).

Question 22

How many pairs of sympathetic chain ganglia are there?

Answer 22

21-23, depending on how tall you are.

Question 23

Which synapse releases norepinephrine?

Answer 23

The synapse of post-ganglionic sympathetic neurons.

Question 24

What are the 2 types of sympathetic ganglia?

Answer 24

Chain and collateral ganglia

Question 25

How many main collateral ganglia are there, and what do they contain?

Answer 25

3. They contain preganglionic axons that didn’t make synapses in the chain ganglia.

Question 26

Which two positions do the axons of preganglionic neurones leave the CNS?

Answer 26

At the cranial or brain stem and sacral or spinal cord levels.

Question 27

What neurotransmitter is used by a somatic efferent neruon?

Answer 27

Acetylcholine

Question 28

If you were told that your cranio-sacral nervous system were activated what does that tell you about your mood?

Answer 28

Relaxed.