THE NERVOUS SYSTEM

Question 1

Why do we have the nervous system?

Answer 1

• detects stimulus and brings about change via a receptor
  -sends electrical messages
  -maintains homeostasis

Question 2

What does the nervous system contain?

Answer 2

Neurons, interneurons and neurglia (support system)

Question 3

What happens during a response via SNS?

Answer 3

Increased heart rate, rate of digestion reduced, bronchodilation

Question 4

What happens during a response via ANS?

Answer 4

decreased heart rate, better digestion, bronchoconstruction

Question 5

What does a neurone consist of?

Answer 5

-Dendrites (branches making connections with other neurones
-cell body (contains nucleus)
-axon hillock (where a.p generated)
-axon
-myelin sheath (electrical insulation)
Axon terminal

Question 6

What is myelin made from?

Answer 6

Protien

Question 7

Where are oligodendrocytes found and what do they do?

Answer 7

CNS
grabs into different neurones
Forms and maintains myelin

Question 8

Where are Schwann cells found?

Answer 8

Peripheral NS

Question 9

Where is the cell body found in sensory neurons?

Answer 9

Middle

Question 10

Meaning of pseudo unipolar?

Answer 10

One axon

Question 11

What does bipolar mean?

Answer 11

2 axons

Question 12

How is the resting membrane potential established?

Answer 12

High K+ conc inside the cell
Higher Na+ conc outside the cell

RMP= -70mv

Question 13

What depolarises the cell?

Answer 13

When the stimulus received causes the voltage to exceed threshold
Voltage gated Na gates open allowing sodium to move into the cells

Question 14

What causes repolarisation?

Answer 14

Change in voltage causes voltage gated K channels to open
K+ leaves the cell
Inside of the cell becomes more negative

Question 15

What is saltatory conduction?

Answer 15

A.p can jump between nodes of ranvier
Quicker in myelinated neurons

Question 16

What triggers vesicles containing neurotransmitter to move and fuse with the synaptic membrane?

Answer 16

A.p reach pre-synaptic membrane
Opens up voltage gated Ca2+ channels
Ca2+ enters

Question 17

What happens after vesicles fuse to membrane?

Answer 17

Neurotransmitters diffuse across cleft
Neurotransmitters act on specific receptors on post synaptic neurones and cause an a.p

Question 18

Why do neurotransmitters have to be inactivated or reabsorbed?

Answer 18

Will cause continuous depolarisation of post synaptic membrane

Question 19

What reflexes involve skeletal muscle?

Answer 19

Somatic

Question 20

What does autonomic reflexes involve?

Answer 20

Smooth muscles and glands

Question 21

What happens to the volume of grey matter in the cerebral cortex during pregnancy?

Answer 21

-reduced

Question 22

What does grey matter do?

Answer 22

-contains neurons to process electrical impulses

Question 23

What is carpel tunnel syndrome?

Answer 23

Compression of median nerve in carpal tunnel causing numbness and tingling

Question 24

What causes carpal tunnel?

Answer 24

-odema
-hameodilution causes soft tissue to become waterlogged and diluted blood has less plasma proteins in so fluid moves out of blood vessels and into interstitial space
-odema compresses the nerve