Neural Tissue and the ANS

Question 1

What exists inside of the neuronal cell body?

Answer 1

This is where biosynthesis of proteins, other macromolecules, and metabolites occurs.

We also traffic and sort macromolecules, cytoplasmic organelles, etc.

Covered in presynaptic buttons

Question 2

What is in a dendrite?

Answer 2

Microtubules, ribosomes

Question 3

What is in an axon?

Answer 3

These guys DO NOT contain ribosomes or golgi (no protein synthesis here)

They do contain neurofilaments, microtubules, kinesins and dyneins, and mitochondria

Question 4

Microglial cells

Answer 4

Resident immune cells of the CNS that are monocytic in origin.

These guys, being monocytes, phagocytose cellular debris

Question 5

Schwann Cells

Answer 5

Main supporting cells of the PNS, they are NOT found in the CNS

These guys make myelin and enwrap large diameter axons. Myelin consists on multiple layers of schwann cell plasma membrane wrapped around an axon.

Note - A single schwann cell forms myelin sheet around only one axon. It envelops with its cytoplasm many other axons but does not myelinate them. Myelinated vs unmyelinated axons have different conductivity.

Question 6

What is a ganglia and what types are there?

Answer 6

A ganglion is a cluster of sensory or autonomic neuron cell bodies.

Sensory use pseudounipolar neurons and satellite cells.

Autonomic use multipolar neurons.

Question 7

Discuss the two plexi we find within the ENS

Answer 7

Submucosal plexus - Muscularis mucosae and villi (shortening of the villi and a squishing out of nutrients in the crypts and between villi)

Myenteric plexus - Peristalsis (coordination of the rhythmic contract-shorten-contract movements of the muscularis externae)