Nerve Tissue Structure and Function

Question 1

What are the two nervous systems and what are their components?

Answer 1

Central Nervous System - brain and spinal cord

Peripheral Nervous System - cranial and spinal nerves

Question 2

Is grey matter central or peripheral in the brain?

Answer 2

Peripheral

Question 3

Name 3 components of grey matter

Answer 3

• Nerve cell bodies
• Dendrites
• Axon terminals
• Non-myelinated axons
• Neuroglia

Question 4

What shape does the grey matter form and what are the anterior and posterior horns called?

Answer 4

• Butterfly shaped
  Anterior - ventral horns
  Posterior - dorsal horns

Question 5

What constitutes white matter?

Answer 5

Myelinated material

Question 6

What two tracts are formed by nerve fibres in white matter?

Answer 6

Ascending and descending tracts

Question 7

What name is given to the gap between the ventral horns?

Answer 7

Ventral fissure

Question 8

What is the name of the main body and extensions of a neuron?

Answer 8

Soma - main cell body

Dendrites - cytoplasmic projections

Question 9

Which parts of a neuron lie in the CNS?

Answer 9

• Soma
• Dendrites
• Proximal part of axon

Question 10

Which parts of the neuron lie in the PNS?

Answer 10

• Distal axons

- Arborisations

Question 11

What are the two types of myelin cell and where is each found?

Answer 11

Oligodendrocyte - Found in CNS

Schwann Cell - Found in PNS

Question 12

What 3 types of neuron make up the reflex arc?

Answer 12

• Sensory
• Interneuron
• Motor

Question 13

What are the 3 types of neuron found outside of the CNS?

Answer 13

• Unipolar
• Bipolar
• Anaxonic

Question 14

Name two specialised neurons found in the CNS

Answer 14

• Purkinje cells

- Pyramidal cells

Question 15

What is the most common neuron in the CNS and what is its structure?

Answer 15

Multipolar - one axon and multiple dendrites

Question 16

Which organelles are abundant in neurons?

Answer 16

• Rough endoplasmic reticulum
• Golgi apparatus
• Free ribosomes
• Vesicles

Question 17

Which organelle aids vesicles to move along the neuron and which directions can they travel?

Answer 17

• Microtubulues
  Anterograde - soma to synapse
  Retrograde - synapse to soma

Question 18

What does neurotransmitter synthesis require?

Answer 18

• Vesicle
• Enzyme
• Neurotransmitter

Question 19

When are neurotransmitters synthesised?

Answer 19

When vesicles travel down the axon

Question 20

Name 2 types of synapse

Answer 20

• Axodendritic
• Axoaxonic
• Dendo-dendritic
• Axo-axonal

Question 21

What are the 3 types of nerve fibre found in the peripheral nerve?

Answer 21

• Sensory
• Integrative
• Motor

Question 22

What are the four layers of a peripheral nerve from outer to inner?

Answer 22

• Paraneurium
• Epineurium
• Perineurium
• Endoneurium

Question 23

What is a fascicle?

Answer 23

A cluster of axons

Question 24

What is the Endoneurium?

Answer 24

Inner loose connection layer of a nerve that surrounds single nerve cells

Question 25

What is the difference between myelinated and non-myelinated?

Answer 25

Myelinated - Schwann cells surround the axon | Non-Myelinated - Axons are on the edge of the Schwann cell

Question 26

What variants influence the speed of nerve conduction?

Answer 26

- Internodal distance - Axon diameter - Myelinatiom

Question 27

Describe 2 differences between A, B and C fibres

Answer 27

A Fibres - thick, fast, in CNS, motor function, myelinated, large internodal distance B Fibres - medium, average speed, in viscera, sensory function, myelinated, small internodal distance C Fibres - thin, slow, in peripheries, sensory function, unmyelinated, no nodes

Question 28

Which membrane initiates myelination?

Answer 28

Mesaxon Membrane

Question 29

Which part of the cell forms multiple layers around an axon?

Answer 29

Sheet extension of the mesaxon membrane

Question 30

What happens to the cytoplasm in myelination?

Answer 30

It is compressed to form myelin

Question 31

What is the name of the cell similar to a Schwann cell but found in the CNS?

Answer 31

Oligodendrocyte

Question 32

How is an Oligodendrocyte different from a Schwann cell?

Answer 32

- It can wrap around more than one axon simultaneously | - Smaller than Schwann cells

Question 33

What 4 cell types support the function of the CNS?

Answer 33

- Oligodendrocytes - Astrocytes - Microglial cells - Ependymal cells

Question 34

Name 2 functions of Astrocyte cells in CNS

Answer 34

- Nutrient transport from blood to nerve cells - Biochemical support - Regulate nerve impulses using glutamate - Contribute to blood-brain barrier

Question 35

Which cell acts as a macrophage in the CNS?

Answer 35

Microglial cell

Question 36

Which type of cell lines the spinal canal?

Answer 36

Ependymal cell

Question 37

What does an Ependymal cell look similar to?

Answer 37

Columnar epithelium but has no basement membrane

Question 38

Name 2 functions of Ependymal cells

Answer 38

- Synthesise and secrete CSF in the ventricles - Cilia move CSF through ventricles to spinal cord - Microvilli absorb CSF for pathogen removal - Modified tight junctions control fluid release into the brain

Question 39

Name 3 symptoms of Multiple Sclerosis

Answer 39

- Fatigue - Decreased mobility - Vision problems - Slurred speech - Numbness and tingling

Question 40

What causes Multiple Sclerosis?

Answer 40

- Autoimmune myelin degradation | - Loss of conduction velocity