Lecture 16 : Neuroanatomy - Cells and Organisation of the Nervous system

Question 1

Name the two parts of the nervous system and what they include.

Answer 1

Central Nervous System, includes the brain and spinal cord.

Peripheral Nervous System, any nerves outside of the CNS stretching into the appendicular skeleton.

Question 2

What are the two types of cells found within the nervous system?

Answer 2

Neurons and Glia

Question 3

What is the purpose of neurons?

Answer 3

Neurons are designed for the transmission of information via action potentials.

Question 4

What is the purpose of glia?

Answer 4

To provide support for neurons.

Question 5

Explain the structure of a neuron.

Answer 5

Dendrites stick out of the cell body like branches, the axon extends from the cell body and can be very long. The end of the axon branches off into axon terminals.

Between the axon and the cell body is the axon hillock.

Question 6

What is the function of each of the segments of the neuron?

Answer 6

Dendrites - receive input, send info to cell body.
Cell body - contains nuclease and organelles, sums input.
Axon hillock - Creates threshold which must be overcome for an AP to be initiated.
Axon - Carries electrical impulses, may or may not be myelinated.
Axon terminal - End of axon, neurotransmitter release.

Question 7

What do you call a group of cell bodies in the CNS?

Answer 7

Nucleus

Question 8

What do you call a bundle of axons in the CNS?

Answer 8

Tract

Question 9

What do you call a group of cell bodies in cerebral cortex or spinal cord?

Answer 9

Grey matter

Question 10

What do you call a bundle of axons in cerebral cortex or spinal cord?

Answer 10

White matter

Question 11

What do you call a group of cell bodies in the PNS?

Answer 11

Ganglion

Question 12

What do you call a bundle of axons in the PNS?

Answer 12

Nerve

Question 13

What are the four zones of a neuron?

Answer 13

Input, summation, conduction, output.

Question 14

What does each zone of the neuron do?

Answer 14

Input : receives a chemical signal
Summation : makes the decision to send the signal further
Conduction : Carries electrical signal
Output : Release of neurotransmitter

Question 15

What are the four types of neurons?

Answer 15

Multipolar, bipolar, unipolar, anaxonic. Draw what they look like.

Question 16

What is an astrocyte, where is it found?

Answer 16

Type of glia found in the CNS with three features.

• Supply nutrients to neurons
• Ensheath blood capillaries
• Transmit information

Question 17

What is microglia, where is it found?

Answer 17

Type of glia found in the CNS with two features.

• Immune cells of CNS
• Engulf microorganisms and debris.

Question 18

What is ependymal cells, where are they found?

Answer 18

Type of glia found in the CNS with two features.

• Line fluid filled spaces of brain and spinal cord.
• Have cilia to circulate cerebrospinal fluid.

Question 19

What are oligodendrocytes, where are they found?

Answer 19

Type of glia found in the CNS with two features.

• support nerve fibres
• myelinate axons of CNS

Question 20

What is a Schwann cell, where are they found?

Answer 20

Type of glia found in the PNS. Ensheaths axon of PNS neuron and support nerve fibres.

Question 21

What is a myelin sheath?

Answer 21

Layer of lipid (fat) wrapped around an axon which improves the conductive velocity of an axon.

Question 22

What are the nodes of ranvier?

Answer 22

Gaps between nodes of myelin, improve conductive velocity.

Question 23

What is information that goes into the brain / CNS called?

Answer 23

Afferent / Ascending

Question 24

What is information that comes out of the brain / CNS called?

Answer 24

Efferent / Descending