Nerve Cells

Question 1

What are the 4 lobes of the cerebrum? Where are they located

Answer 1

Frontal lobe, occipital lobe, parietal lobe and temporal lobe

Question 2

What cells are lost in Parkinsons disease

Answer 2

In the midbrain there is an area called the substantia nigra. In here there are cells found that are called dopaminergic neurons. Parkinson’s disease results in the loss of these neurons

Question 3

Where is the grey matter and white matter? What do they comprise of

Answer 3

Grey matter is the cell bodies and white matter is the axons. In the brain grey matter is outside whereas in the spinal cord grey matter is inside

Question 4

How many layers of cells are there in the cerebral cortex

Answer 4

6

Question 5

Define those layers

Answer 5

Layer 1 is at the top. It has very low density of cells. This is the area where the axon tracks are traveling.

II is external granular layer, III is external pyramidal cell layer, IV is internal granular layer, V is ganglionic layer, VI is multiform (polymorphic) cell layer.

Question 6

How do you identify the layer V of the cerebral cortex

Answer 6

Identify the large pyramidal cells

Question 7

What are parenchymal cells

Answer 7

They are multi polar neurons, they have multiple processes coming out of them, perhaps making connection to many neurons both from the dendrites and the axons.

Question 8

How do you identify cerebellum

Answer 8

Branched structure from low zoomed picture

Question 9

What are the layers of the cerebellum

Answer 9

Molecular, purkinje and granular

Question 10

What cells are found in the molecular layer

Answer 10

Stellate and Basket cells

Question 11

How do you differentiate the dorsal and ventral horn

Answer 11

From the blood vessel coming out of the ventral horn.

Also know how to identify the central canal

Question 12

What is found in the ventral horn

Answer 12

Cell bodies and axons of the motor neurons that make choline acetyltransferase

Question 13

What does the motor neurons have that makes them particularly easy to identify in staining methods

Answer 13

They have nissle substance. The staining method used stain rRNA so staining the ribosomes and the nucleolus

Question 14

What happens in ALS

Answer 14

Amyotrophic Lateral Sclerosis

Patients can think, process and recall information fine but they cannot correctly move due to diseased motor neurons.

Question 15

Describe dendrons, cell body, axons, synapses

Answer 15

Dendrons are Input, cell body is integration, axons are conductors and synapses are output

Question 16

What are the 3 types of neurons

Answer 16

Pyramidal neurons which are interneurons, motor neurons which only transmit signals after receiving them and then sensory neurons that only detect signal

Question 17

What are glia cells of the CNS

Answer 17

Glia cells are supporting cells of the CNS

1. Astrocytes
2. Ependyma
3. Microglial cells
4. Oligodendrocytes

Question 18

What are the functions of astrocytes

Answer 18

1) Supportive (in a skeletal sense)
2) Insulating, particularly with regard to synapses
3) Electrolyte balance, particularly regarding K+ ions
4) pH balance of extracellular milieu
5) Sequestration of neurotransmitters
6) Communicate with capillary endothelial cells
7) Interactions with immune system
8) Phagocytosis of extracellular debris
9) Induce blood brain barrier

Question 19

What are the types of astorcyte

Answer 19

1. Fibrous astrcytes

2. Protoplasmic astorcytes

Question 20

What is the blood brain barrier

Answer 20

foot processes of astrocytes induce endothelial cells to form tight junctions

Question 21

What are the 3 layers

Answer 21

1. Dura Mater - highly dense connective tissue
2. Arachnoid mater
3. Pia Mater - very very thin layer of connective tissue

Question 22

Where does the capillaries and the csf runs in the brain

Answer 22

In subarachnoid space

Question 23

What makes csf

Answer 23

Choroid plexus cells

Question 24

Know the ventricular system

Answer 24

The csf is also present here

Question 25

What comprises in the ventral root of the spinal cord

Answer 25

The motor neurons have their axons coming out of the spinal cord and then joining the muscles

Question 26

What does dorsal root has

Answer 26

Sensory neurons

Question 27

Where does the sympathetic chain and the sympathetic ganglion reside?

What is their function

Answer 27

Sympathetic chain runs along the spinal cord. They form the sympathetic system

Question 28

What is the function of sympathetic and parasympathetic system

Answer 28

Sympathetic is involved in fight or flight reponse

Parasympathetic is involved in rest and digest

Question 29

When do both of the system make their synaptic contacts

Answer 29

Sympathetic neurons send their axons to the ganglions in the sympathetic chain system, which then send their axons to the motors or to the organs.

Parasympathetic neurons have larger axons, makes synaptic contacts with other ganglions which then connect their axons to the desired tissues or organs like the stomach

Para do not innervate in the sympathetic chain system (do not have synapses in this region)

Question 30

Where does the sympathetic ganglions make their synaptic contacts with

Answer 30

In the brain and the between the post synaptic ganglions located in the ganglions. This is different from DRGs. (dorsal root ganglions)

The synapses are in the ganglions (in the swellings)

Question 31

Where is the enteric nervous system found

Answer 31

In the gut

Question 32

Function of submucosal plexus and myenteric plexus

Answer 32

Submucosal is responsible for glandular secretions and for sensing pH whereas the myenteric plexus is associated with controlling the smooth muscles of the gut

Myenteric is at the inside

Question 33

Where are the sensory nerves located

Answer 33

At the dorsal root ganglion just outside the spinal cord.

Ganglion is basically a swelling

Question 34

How are DRG and sympathetic nervous system ganglions different

Answer 34

DRGs do not form synapses at the ganglions but instead they make synapses at the brain and at the target organs

Question 35

What are DRGs surrounded by

Answer 35

Satellite cells, they are quite small surround the DRGs all over

Question 36

What is a peripheral nerve

Answer 36

Ventral roots of the spinal cord consists of the axons of the nerves that form the peripheral nerve

Question 37

Difference in the function of schwann cells and oligo

Answer 37

Olio can myelinate mutliple axons whereas schwann can only mylienate 1 axon

Question 38

What are the 3 layers in the peripheral nerves

Answer 38

The myelinated axons are surrounded by endoneurium, a group of them is surrounded by perineurium and all of them are surrounded by epineurium

Question 39

What happens in Charcot Marie Tooth Disease

Answer 39

Myelins sheaths are damaged leading to a damaged neurons

Question 40

Wallerian degneration

Answer 40

A mechanism of rapid axon degenration. it is physiological

Question 41

What happens in neuropathy

Answer 41

Neuropathy in daibetes is assoicated with the loss of peripheral nerves which, in case if their is trauma to the foot, can lead to gangerence if undetected which can then result in the treatment involving foot amputation