Lecture 1

Question 1

What is physiology?

Answer 1

The study of how the body works.

Question 2

What does the nervous system enable?

Answer 2

Rapid and flexible response to changes in external and internal environments of the body.

Question 3

3 functions of the nervous system? (with brief description).

Answer 3

Sensory (senses internal and external changes),
Integrative (analyses and stores sensory info. making decisions on appropriate voluntary and involuntary responses),
Motor (initiates muscular activity or glandular secretions).

Question 4

concentration of nerve cells per 1cm^3 of brain?

Answer 4

50 million.

Question 5

What are the 3 types of neurons?

Answer 5

Sensory neurons, interneurons, motor neurons.

Question 6

What inhibits flexor muscles from contracting during the knee-jerk reflex?

Answer 6

Interneurons.

Question 7

2 divisions of the nervous system?

What parts do they involve?

Answer 7

Central nervous system (brain and spinal cord),

Peripheral nervous system (cranial and spinal nerves).

Question 8

What 5 functions does the CNS control?

Answer 8

Integrates sensory information, 
Generates thoughts and emotions,
Stores memory,
Makes decisions,
Initiates motor activity.

Question 9

What 2 functions does the PNS control? And where do the instructions from both arise from?

Answer 9

Carry nerve impulses to and from CNS.
Connect CNS to sensory receptors, muscles and glands.

Arises from brain and spinal cord.

Question 10

Do neurons divide?

Answer 10

No.

Question 11

Do (neuro)glia have one function? Can they divide?

Answer 11

No, many. Yes (e.g. forming glial scars in brain disease).

Question 12

How many neurons and glial cells does the brain contain?

Answer 12

10^11 neurons, 10^12 glial cells. Both contribute equally to brain weight.

Question 13

3 parts of a neurone?

Answer 13

Cell body (soma/perikaryon),
Dendrites,
Axon.

Question 14

Are dendrites and axons myelinated?

Answer 14

Dendrites aren’t, axons usually are.

Question 15

Where do axons propagate nerve impulses to, and where do they terminate?

Answer 15

Propagate to another neuron, muscle fibre, gland.

Terminate at axon terminals/synapses.

Question 16

What myelinates axons?

Answer 16

Oligodendrocytes in CNS, Schwann cells in PNS.

Question 17

What does the cell body of neurons contain?

Answer 17

Normal cell organelles.

Question 18

The perikaryon is the site of protein synthesis and degradation. What’s significant about a certain organelle that helps it accomplish this?

Answer 18

It’s rough ER is enlarged. Made up of Nissl substance.

Question 19

How does structure differ between dendrites and axons?

Answer 19

Dendrites: Short, bristle-like, highly branched.
Axons: long, thin.

Question 20

What receives nerve impulses?

Answer 20

Dendrites.

Question 21

What are the 3 types of neurons by function?

Answer 21

Sensory neurons, interneurons, motor neurons.

Question 22

What unique features do neuronal organelles present?

Answer 22

Very long axons, so nerve terminals remote from cell body.
Materials transported from between cell body and axons (orthograde/anterograde and retrograde transport).
Well defined cytoskeleton with special neurofilament.

Question 23

4 components of neuronal cytoskeleton?

Answer 23

Actin microfilaments, microtubules, neurofilaments, tau.

Question 24

How does Tau contribute to Alzheimer’s?

Answer 24

Accumulates in nerve cells in the brain, as neurofibrillary tangles.

Question 25

How many types of microtubule are there, what are they, and how large are they?

Answer 25

2: α-tubulin, β-tubulin.

450 amino acids (~50kDa).

Question 26

How many protofilaments form the tip of a microfilament?

Answer 26

13.

Question 27

Neurofilaments are intermediate filaments. What are the 3 types, and how much does each weigh? Also, where are they found?

Answer 27

NF-L: 70kDa. Core.
NF-M: 140kDa. Side-arms.
NF-H: 210kDa. Side-arms.

Question 28

Fast and slow anterograde. How fast are they?

Answer 28

Fast = 200-400mm/day.
Slow = 7mm/day.

Question 29

What are the 3 types of neurons by polarity? And how does their structure differ?

Answer 29

Bipolar, - one main dendrite and one axon.
Unipolar, - one process from cell body.
Multipolar - many dendrites and one axon.

Question 30

Where are bipolar, unipolar and multipolar neurons found?

Answer 30

Bipolar - retina, inner ear, olfactory region in brain.
Unipolar - always sensory neurons, e.g. temperature.
Multipolar - most in CNS.

Question 31

4 types of glial cells in CNS?

Answer 31

Astrocytes, Oligodendrocytes, Microglial, Ependymal.

Question 32

Location and functions of Astrocytes?

Answer 32

Surrounds neurons and blood vessels.
Aids neuronal cell migration and axon growth.
Contribute to blood brain barrier.
Regulate ionic environment of nerve cells.
Take up transmitters.
Make growth factors.
Activated in disease - can form glial scars.

Question 33

What are oligodendrocytes a source of?

Answer 33

CNS myelin - (can myelinate over 50 axons).

Question 34

What are microglial cells?

Answer 34

Macrophages, able to remove debris from dying neurons.

Question 35

Where may microglial cells enter from?

Answer 35

Blood.

Question 36

What do ependymal cells do?

Answer 36

Line fluid filled ventricles. Produce and circulate cerebrospinal fluid.

Question 37

2 types of glial cells in PNS?

Answer 37

Schwann cells and satellite cells.

Question 38

What do Schwann cells produce?

Answer 38

Myelin to coat around one single axon.

Question 39

Where are satellite cells located, and what do they look like?

Answer 39

Flattened cells around cell bodies of neurons in PNS ganglia.