General

Question 1

What are the two types of potentials

Answer 1

Localised

• passive and operate over short distances
• graded (info encoded by amplitude)
• typically sensory receptors endings and PS membranes

Action potentials

• all or nothing
• regenerative
• info encoded by frequency and timing
• directional

Question 2

What are the 4 glial cells

Answer 2

1. Astrocytes
2. Oligodendrocytes
3. Ependymal
4. Microglia

Question 3

General characteristics of Glial cells

Answer 3

Large negative resting membrane potential- 90mV; due to K+ distribution

Electrically coupled at gap junctions

Can divide and multiply

Question 4

5 properties of astrocytes

Answer 4

1. Scaffold for neurones and blood vessels
2. Regulate external environment
3. Maintain integrity of BBB
4. Regulate synaptic transmission
5. NS repair - become phagocytic, replace damaged cells with glial scar tissue

Question 5

Role of oligodendrocytes

Answer 5

1. Large number in white matter

2. Resemble Schwann cells of PNS; can form myelin for 3-50 nerve fibres

Question 6

Role of Ependymal cells

Answer 6

1. Line cavities and ventricles

2. CSF production and movement (cilliated cells)

Question 7

Role of microglia

Answer 7

1. White and grey matter
2. Macrophages of CNS
3. Mediates immune response in CNS
4. Act as APCs to interact with T-helper cells

Question 8

What are the 3 germ layers

Answer 8

1. Ectoderm
2. Mesoderm
3. Endoderm

Question 9

What does the Ectoderm become

Answer 9

Epidermis and CNS

Question 10

What does Mesoderm become

Answer 10

Muscles
Bones
Kidneys 
Circulatory system 
Gonands

Question 11

What does endoderm become

Answer 11

Inner mucosal lining- GI and respiratory

Question 12

Describe the development of CNS and PNS

Answer 12

1. Neural tube forms CNS

2. Neural crest forms PNS

Question 13

Describe cortical layer development

Answer 13

1. 3 processes: proliferation, migration, differentiation
2. Neurones migrate along radial glial cells
3. Inside out cortical development

Question 14

Describe neuralation

Answer 14

Formation of neural tube from flat sheet of ectoderm, induced my signalling from notochord

Question 15

What does the neural tube differentiate into

Answer 15

1. Spinal cord

2. 3 primary brain vesicles

Question 16

How do dendrites ‘scale up’ synaptic input to achieve a democratic weighting

Answer 16

• thinner dendrites
• higher resistance
• higher voltage required (Ohm’s law)

Question 17

What is the order of embryo development

Answer 17

Day 0: fertilisation
Day 1: blastomere 
Day 3: Morula 
Day 6: Blastocyte 
Gasturlaton leads to 3 germ layers

Question 18

What are the 3 primary vesicles

Answer 18

Prosencephalon: forebrain
Mesencephalon: midbrain
Rhombencephalon: hindbrain

Question 19

What does the prosencephalon differentiate into

Answer 19

• Telencephalon: cerebral cortex
• Diencephalon: thalamus, hypothalamus and epithalmus
• Optic vesicles
• lateral and 3rd ventricles

Question 20

What does the Mesencephalon differentiate into

Answer 20

• tectum and tegmentum

- cerebral aqueduct

Question 21

What does the Rhombencephalon differentiate into

Answer 21

• metencephalon (cerebellum and pons)
• myelenceohalon (medulla)
• 4th ventricle