Wk3 Nerves, Synapses and Neurotransmitters

Question 1

The two main nervous systems are?

Answer 1

CNS (Central Nervous System)

AND

PNS (Peripheral Nervous System)

Question 2

What is included in the CNS?

Answer 2

The brain and Spinal cord.

Question 3

What is included in the PNS?

Answer 3

The nerves in the body:

• Communication of information to and from CNS
• Regulation of autonomic function
• 12 pairs of cranial nerves and 31 of spinal nerves

Question 4

What are the two main divisions in the PNS?

Answer 4

Sensory (afferent) division and Motor (efferent) Division

Question 5

Describe the ‘Somatic’ System (voluntary):

Answer 5

Voluntary control of body movements

Question 6

Describe ‘Autonomic Nervous System (involuntary):

Answer 6

• Sympathetic (The fright, fight and flight)

- Parasympathetic (Rest and Digest)

Question 7

A nerve is a _______ of axons - It may be myelinated or ________; sensory, motor or mixed.

Answer 7

A nerve is a ‘bundle’ of axons - It may be myelinated or ‘non-myelinated’; sensory, motor or mixed.

Question 8

Describe a tract:

Answer 8

Non-enclosed bundle of axons in CNS usually sensory or motor - NOT mixed.

Question 9

Are ‘Nuclei’ (a) A group of cell bodies underneath white matter in the CNS or (b) Is matter found in the nucleus of a cell, to assist CNS function?

Answer 9

It is:

(a) A group of cell bodies underneath white matter in the CNS.

Question 10

Ganglion is:

Answer 10

A group of cell bodies outside CNS

Question 11

Dendrites

Answer 11

Derive from the Greek word “tree” little branches that extend out from the Neuron that relay information to the cell body.

Question 12

Does an axon transmit information?

Answer 12

Yes, the long arm that transmits information from the other Neurons, muscles and glands.

Question 13

Myelin Sheath is: (a) Part of the neuron that relays information to other neurons OR (b) Insulating fatty tissue that is around the axons and some neurons.

Answer 13

It is:

(b)Insulating fatty tissue that is around the axons and some neurons.

Question 14

A synapse is:

Answer 14

The junction or region between the axon of one neuron and the dendrites or cell body of another

Question 15

What are the 3 types of neurons?

Answer 15

• Sensory Neuron
• Interneuron Neuron (Relay)
• Motor Neuron

Question 16

Describe the role of the Sensory Neuron:

Answer 16

Carries impulses from receptors (eg. pain receptors in skin) to the CNS (brain or spinal cord)

Question 17

Describe the role of the Interneuron:

Answer 17

Carries impulses from sensory nerves to motor nerves.

Question 18

Describe the role of the Motor Neuron

Answer 18

Carries impulses from CNS to effectors

eg. muscle (to bring about movement) or glands (to bring about secretion of hormone eg. ADH)

Question 19

Another word for Glial cells is: ________

And what does it do?

Answer 19

‘Neuroglia’

Neuroglial cells support, insulate and protect neurons.

Question 20

Glial cells found in the CNS are:

Answer 20

• Oligodendrocytes: produce the myelin sheath.
• Astrocytes: Star shaped cells. That form the blood-brain barrier.
• Ependymal cells: These are the columnar epithelial cells covering the ventricles of brain and canal of spinal cord.
• Microglia cells: These are small, mesodermal, elongated cells. They are derived from precursor cells in the bone marrow, and are phagocytic.

Question 21

Glial cells found in the PNS are:

Answer 21

• Schwann cells: Surround all axons; responsible for myelination of peripheral axons. They participate in the repair process after injury.
• Satellite cells: Surround neuron cells bodies in ganglia: regulates oxygen and carbon dioxide nutrients, and neurotransmitter levels around neurons.

Question 22

Main features of the neuron structure:

Answer 22

• Dendrites: carry impulses towards the cell
• Axon: carry impulses away from the cell
• Myelin sheath:insulation, rapid conduction
• Synaptic terminal:vesicles with NT (eg. noradrenaline, adrenaline, acetylcholine)

Question 23

What is neurotransmitters? Name the two types of functions.

Answer 23

Chemicals used for neuronal communication with the body and the brain.
Chemically through: Acetylcholine, Biogenic amines, Peptides etc.
Functionally eg. Excitatory or inhibitory

Question 24

Two forms of actions that NT produces:

Answer 24

Excitory:

Inhibitory:

Question 25

Electrical Synapses is:

Answer 25

Gap junction: that allow local current to flow.

Question 26

Chemical Synapses has 3 components name them:

Answer 26

• Presynaptic terminal
• Synaptic cleft
• Postsynaptic membrane

Question 27

Is ACh synthesised in CNS and PNS?

Answer 27

Yes, ACh is a NT used by the spinal cord neurons to control muscles.