Nerves

Question 1

What are the 3 basic functions of the nervous system?

Answer 1

1. Detect/sense changes in internal/external environment
2. Process and integrate sensory information
3. Initiate a response against the change

Question 2

What are the divisions of motor neurone

Answer 2

• somatic

- autonomic

Question 3

What are the classes of autonomic motor neurones

Answer 3

• parasympathetic

- sympathetic

Question 4

Name the structures involved in the CNS

Answer 4

Spinal cord, brain, brainstem

Question 5

Name the structures involved in the PNS

Answer 5

• motor neurone
• sensory neurone
• 31 pairs of spinal nerves
• ganglion (plural: ganglia)

Question 6

What neurones are involved in the transmitting afferent information?

Answer 6

sensory neurones

Question 7

State the pathway of afferent division

Answer 7

• carry information towards the CNS (in response of pain, pressure or stretch)
• synapse/communicate with neurones in the spinal cord which results in an appropriate response to stimulus

Question 8

Where are the cell bodies of the sensory neurones located?

Answer 8

in the dorsal root ganglion adjacent to the spinal cord

Question 9

What neurones are involved in the efferent division

Answer 9

motor neurones

Question 10

State the pathway of the efferent division

Answer 10

motor neurones carry information away from the spinal cord to the skeletal muscle fibres

Question 11

How would a response be carried out at the motor nerves/neurones?

Answer 11

motor nerves release transmitter molecules that will result in an appropriate response to occur

Question 12

Function of neurones

Answer 12

• receive signals from other cells
• transmit signals from the cell body
• transmit signals to other cells

Question 13

Function of glial cells

Answer 13

• form myelin sheath surrounding axons
• repair damage to cells
• maintain ionic environment around cells
• help in removal of neurotransmitters

Question 14

Function of ependymal cells (3)

Answer 14

• make up ependymal membrane
• secrete cerebrospinal fluid
• make up brain-CSF barrier

Question 15

function of astrocytes (4)

Answer 15

• regulate chemicals in the brain’s extracellular fluid
  + [ions], [glucose], take up neurotransmitters
• maintain blood-brain barrier
• repairs nervous system
• provide structural supprt for neurones (provide scaffolding)

Question 16

Function of oligodendrocytes

Answer 16

• form myelin sheath around axons in CNS

Question 17

Function of Schwann cells

Answer 17

• form myelin sheath around axons in PNS

- help in regeneration and regrowth of axons

Question 18

function of microglia

Answer 18

• phagocytose abnormalities (pathogens, plaques and damaged cells)

Question 19

How is action potential generated?

Answer 19

• electrical signal arrives at the dendrites and changes the electrical charge of the membrane
• potential is generated
• when potential threshold is passed, an action potential is generated which passes down the axon

Question 20

How do neurones communicate chemically? (using chemical messengers)

Answer 20

• when the action potential is passed down to the axon terminal, calcium is released
• release of calcium triggers vesicles containing neurotransmitters to move and fuse with the membrane
• neurotransmitters are released by exocytosis into the synaptic gap
• neurotransmitters bind with receptors on the post-synaptic membrane of the dendrite (of the next cell)