Structure Of The Nervous System

Question 1

Function of glia. (5)

Answer 1

▪more than passive support 
▪at least as numerous as neurons 
▪provide trophies support
▪regulate electrical activity 
▪protect neurons from external factors

Question 2

Types of glia in the PNS(2)

Answer 2

▪Satellite cells

▪Schwann cells

Question 3

Function of satellite cells(2)

Answer 3

▪Surround neuron cell bodies in ganglia

▪Regulate oxygen, carbon dioxide, nutrient and neurotransmitter levelled around neurons in ganglia

Question 4

Function of Schwann cells (3)

Answer 4

▪Surround axons in the PNS
▪Myelination of peripheral axons
▪Participate in repair process after injury

Question 5

Name the glial cells in the CNS (4)

Answer 5

▪Oligodendrocytes
▪Astrocytes
▪Microglia
▪Ependymal cells

Question 6

Function of Oligodendrocytes (2)

Answer 6

▪Myelinate CNS axons therefore insulate
▪Provide structural framework
▪Generate myelin sheath

Question 7

Function of astrocytes (5)

Answer 7

▪Maintain blood brain barrier 
▪Provide structural support 
▪Extracellular ion balance. nutrient provision to neurons. Maintain dissolved gas concentrations. 
▪Absorb and recycle neurotransmitters. 
▪Form scar tissue after injury. Repair 
▪Gliotransmitter release

Question 8

Function of microglia

Answer 8

▪Remove cell debris, wastes and pathogens by phagocytosis. Immune response. Clearance of extracellular release.
▪Synaptic pruning

Question 9

Function of Ependymal cells

Answer 9

▪Line ventricles (brain) and central canal (spinal cord)
▪Assist in producing, circulating, and monitoring of cerebrospinal fluid
▪Pool of stem cells

Question 10

What are the three components of a tripartite synapse?

Answer 10

▪Presynaptic terminal nerve
▪Postsynaptic spine
▪Glial cell

Question 11

Function of glia in tripartite synapse

Answer 11

▪Regulate neurotransmitter recycling
▪Release gliotransmitters e.g. ATP and D serine
▪Ensheath synapses

Question 12

Neural tube formation(4)

Answer 12

▪Neural plate forms a furrow at the medial hinge point
▪Neural folds and groove presents epithelium delaminates
▪Neural folds contact to form neural tube but not yet fused
▪Neural folds fused to produce neural crest

Question 13

What are the three layers of cells in the neural plate?

Answer 13

▪Endoderm
▪Mesoderm
▪Exoderm

Question 14

What does the Endoderm form?

Answer 14

Internal tubes in the body

Question 15

What does the Endoderm form?

Answer 15

Flesh

Question 16

What for s the Endoderm form?

Answer 16

Outer layers and the nervous system

Question 17

Once the tips of the neural folds touch. What happens?

Answer 17

▪Key differentiation leads to formation of neural crest cells
▪Epidermis grows on top and seals the tube

Question 18

Where in the nervous system ate dorsal roo ganglia found and what sort if neurons do they contain?

Answer 18

▪In the PNS in a chain running along the vertebral column

▪sensory neurons, nociceptors, mechanosensitive.

Question 19

What would happen to the axons of dorsal door ganglia grown in vitro in proximity to a cluster of cells expressing semiphorin3A?

Answer 19

▪They would grow away from/be repelled by the cells.