Histology

Question 1

What are the major cells of CNS

Answer 1

neurons and glia cells

Question 2

What are the five sorts of glia cells in the CNS

Answer 2

astrocytes, oligodendrocytes, ependymal cells, satellite cells

Question 3

What are the immune cells of CNS

Answer 3

microglia

Question 4

What is special about the most superficial 1cm of the brain?

Answer 4

consists of 6 layers of different densities. Layer 1 being the most superficial. This 6-layers arrangement is found in different regions of the brain

Question 5

What is the advantage of using silver stain over H&E stain on neurons

Answer 5

can see processes under silver stain and see different neuronal morphology

Question 6

Where is the CSF formed?

Answer 6

CSF is formed by cuboidal cells of the choroid plexus, which is the vascular structure on the wall of ventricles

Question 7

What is the function ependymal cell?

Answer 7

They line the ventricular system and have finger like projections that help the movement of CSF in central canal

Question 8

Give four distinct qualities of neurons

Answer 8

1) specialised for signalling
2) high level of protein synthesis
3) metabolically limited, rely on blood supply for energy
4) terminally differentiated, apart from a group of adult stem cells

Question 9

What are the characteristics of actin

Answer 9

actin is dynamic and can allow shape change and movement. It forms small spines for signal input and output

Question 10

Intermediate filaments are ________ cytoskeletal structures

Answer 10

permanent

Question 11

What are the characteristics of microtubules?

Answer 11

dynamic, composed of tubulin, important for axonal transport, important in disease

Question 12

What is the name of the 1) input zone 2) cell body 3) output zone of a neuron

Answer 12

dendrite, soma, axon

Question 13

Where are the proteins produced in a neuron

Answer 13

in the nissl bodies of the soma. They are rough ER and free ribosomes

Question 14

What are the passive functions of astrocytes

Answer 14

1) neurotransmitter uptake and degradation
2) K+ uptake as depolarisation releases a lot of K+
3) neuronal energy supply. Take in glucose and convert it to something neurons can use
4) maintenance of BBB
5) injury response and recovery

Question 15

What happens if astrocytes are not there to reuptake the neurotransmitters?

Answer 15

the intensity and duration of action potential increase, which is harmful for the neuron

Question 16

How does astrocyte perform its active function

Answer 16

Astrocytes are excitable (by NT, trauma, spontaneous or inflammatory mediators). Calcium is released, which trigger synaptic vesicle release

Question 17

How does astrocyte use calcium to communicate with other nearby cells?

Answer 17

Calcium release from cell will initiate release of gliotransmitters via mechanisms with calcium dependent vesicular release

Question 18

T/F astrocyte releases calcium to directly cause vasoconstriction of blood vessels

Answer 18

False, calcium triggers the release of gliotransmitter vesicles, and it’s the transmitter that causes the vasoconstriction

Question 19

Why is it important that astrocyte has a role in blood vessel tone control

Answer 19

Glial cells can directly regulate vascular tone and respond to the energy requirement for the neurons

Question 20

What is the main difference between oligodendrocytes and Schwann cells

Answer 20

Oligodendrocytes (CNS) wrap around several axons
Schwann cells (PNS) wrap around one axon

Question 21

What are Nodes of Ranvier

Answer 21

small gaps between myelin sheath designed for ion conduction

Question 22

What does microglia resemble

Answer 22

phagocytic macrophages

Question 23

What is the function of microglia in 1) normal state 2) injury

Answer 23

1) send out / retract processes to sample nearby synapses

2) converge processes onto inflamed area, release harmful chemicals to control damage

Question 24

Endoneurium surrounds ___1___ , forming the bundle called ___2___ , which is surrounded by ___3___ . Multiple nerve bundles will form a peripheral nerve, which is surrounded by ___4___

Answer 24

1) individual axon
2) fascicle
3) perineurium
4) epineurium

Question 25

What are the two types of ganglion, and what do they contain?

Answer 25

Sensory, containing cell bodies of sensory neurons
Autonomic, containing cell bodies of post-ganglionic neurons.

There are also satellite cells in ganglia