lecture 16 - nervous system organisation

Question 1

What are the two types of cells in the nervous system?

Answer 1

Neurons and glia

Question 2

What are the key components of a neuron (4)?

Answer 2

Dendrites, cell body, axon, axon terminals

Question 3

In the CNS, what is the name for a group of cell bodies?

Answer 3

Nucleus

Question 4

In the CNS, what is the name for a bundle of axons?

Answer 4

Tract

Question 5

In the PNS, what is the name for a bundle of cell bodies?

Answer 5

Ganglion

Question 6

In the PNS, what is the name for a bundle of axons?

Answer 6

Nerve

Question 7

In cerebral cortex or spinal cord, what is the name for an area made up of a group of cell bodies?

Answer 7

Grey matter

Question 8

In cerebral cortex or spinal cord, what is the name for an area made up of bundle of axons?

Answer 8

White matter

Question 9

What is the direction of information flow along a neuron?

Answer 9

From dendrites (input zone) to axon terminals (output zone)

Question 10

What are the four ‘zones’ of a neuron?

Answer 10

Input zone, summation zone, conduction zone, output zone

Question 11

What are the components of the input zone of a neuron?

Answer 11

Dendrites, cell body

Question 12

What are the components of the summation zone of a neuron?

Answer 12

Axon hillock

Question 13

What are the components of the conduction zone of a neuron?

Answer 13

Axon

Question 14

What are the components of the output zone of a neuron?

Answer 14

Axon terminals

Question 15

What is the function of the input zone of a neuron?

Answer 15

Receive chemical signals via synapses from pre-synaptic cells

Question 16

What is the function of the summation zone of a neuron?

Answer 16

Sums together multiple chemical signals into a single electrical impulse (action potential)

Question 17

What is the function of the conduction zone of a neuron?

Answer 17

Carrying electrical signals (action potentials) from the cell body to the output

Question 18

What is the function of the output zone in a neuron?

Answer 18

Connect with input zone of other neurons or effectors, and communicate with neurotransmitters during a synapse

Question 19

What are the 4 morphological types of neuron?

Answer 19

Multipolar, bipolar, unipolar, anaxonic

Question 20

What a multipolar neuron?

Answer 20

A neuron with multiple input processes.

Question 21

What is a bipolar neuron?

Answer 21

A neuron with 1 input and 1 output process only

Question 22

What is a unipolar neuron?

Answer 22

A neuron with 1 process, which splits into the input and output regions

Question 23

What is an anaxonic neuron?

Answer 23

A neuron that has no distinct axon

Question 24

What are the types of glia found in the CNS?

Answer 24

Astrocytes, Microglia, Ependymal cells, oligodendrocytes

Question 25

What is the function of astrocytes?

Answer 25

Supply neurons with nutrients and ensheath blood capillaries to regulate CNS blood supply. Control chemical environment by mopping up leaked ions and recycling excess neurotransmitters. Involved in injury response

Question 26

What is the function of microglia?

Answer 26

They are immune cells that are able to engulf microorganisms and debris

Question 27

What are ependymal cells?

Answer 27

Glia that line fluid filled spaces and have cilia that circulate cerebrospinal fluid.

Question 28

Where are the cilia located on ependymal cells?

Answer 28

On the apical surface

Question 29

How is cerebrospinal fluid circulated in the CNS?

Answer 29

Ependymal cells which have cilia

Question 30

What is function of oligodendrocytes?

Answer 30

Support nerve fibres. Ensheath CNS axons with myelin which forms insulating sheath that increase conduction velocity

Question 31

What is the key glial cell of the PNS?

Answer 31

Schwann cell

Question 32

What is the function of Schwann Cells?

Answer 32

Support peripheral nerve fibres. Ensheath fibres with myelin to facilitate rapid conduction

Question 33

What is the name for gaps between Schwann cells on the axon of a neuron?

Answer 33

Nodes of Ranvier

Question 34

Is communication electrical or chemical at a synapse?

Answer 34

Chemical

Question 35

What occurs at the pre-synaptic cell before/during a synapse?

Answer 35

Action potential travels down axon causes synaptic vesicles to release packets of neurotransmitter via exocytosis. These enter the synaptic cleft between the post-synaptic cell.

Question 36

What occurs during/after the synapse at the post-synaptic cell?

Answer 36

neurotransmitters bind to receptors in the dendrites, which create electrical signals that sum at the summation zone, creating an action potential.

Question 37

What is type of information flow when info flows from PNS to CNS?

Answer 37

afferent/ascending

Question 38

What is type of information flow when info flows from CNS to PNS?

Answer 38

Efferent/descending

Question 39

What are interneurons?

Answer 39

Neurons found exclusively in the CNS, that connect spinal sensory and motor neurons.