Nervous Tissue

Question 1

What are neurones

Answer 1

Great communicators
Recieve info chiefly via synapses integrate info then transmit electives impulses to another neurone or effector cell
Most are multipolar with many dendrites

Question 2

What are glial cells

Answer 2

More numerous than neurones

4 major types

Question 3

What are the 4 types of glial cells

Answer 3

Astrocytes - many numerous processes, roles in support, maintain blood-brain barrier, enviro homeostasis

Oligodendrocytes - produce myelin in cns not pNS

Microglia- cells of similar lineage to macrophages, immune monitoring and antigen presentation

Ependymal - cuboidal/columnar epi that lines the cavities in cns such as ventricles

Question 4

What is a ganglion

Answer 4

A group of neurones outwith cns

Question 5

What are the characteristics of a neurone

Answer 5

Cell body - soma has the nucleus and cell organelles

Axon - long process often stretching out for long distances trans data

Dendrites - numerous short branches increase SA for connections form axons

Synapse - specialised junction between axon and cell to allow communication

Question 6

What is the axon hillock

Answer 6

Axon arises from swelling in soma which is the axon hillock

This is imp as this is where action potentials arise

Question 7

What are the different neuronal classes

Answer 7

Unipolar
Multipolar
Bipolar
Pseudo unipolar

Question 8

What is axonal transport

Answer 8

Energy consuming mechanism to move material up and down axon

Question 9

How does axonal transport work

Answer 9

Depends upon molecular motors such as kinesin which use microtubules as a sort of railway track to haul attached organelles, vesicles etc

Question 10

What is anterograde transport

Answer 10

Fast axonal transport move material away form stroma

Question 11

What is retrograde transport

Answer 11

Slow axonal transport

Question 12

What does the pNS consist of

Answer 12

Consists of nerves and ganglia include elements of both somatic and autonomic nervous systems

Question 13

what does a peripheral nerve consist of

Answer 13

Axons
Schwann cells some prod myelin
Fibroblasts whic prod fibrocollagenous material
Blood vessels

Question 14

What are the connective tissue sheaths of the peripheral nerve

Answer 14

Epineurium - surrounds whole nerve

Perineurium - surrounds fascicle

Endoneurium - surrounds fibres within a fascicle

Question 15

What are Schwann cells

Answer 15

Unmyelinated axons in Schwann cells

Question 16

What are nodes of ranvier

Answer 16

Myelin sheaths not complete along axon but rather include regularly spaced breaks

Question 17

What does myelination do to axons

Answer 17

Myelination increases speed

Question 18

What is Grey matter

Answer 18

Huge number of neurons cell processes synapses and support cells

Question 19

What is white matter medullary centre

Answer 19

Axons most myelinated and their support cells

Question 20

What is a Neuropil

Answer 20

A mat of neuronal and glial cell processes hat occupies much of grey matter

Question 21

Explain synapses

Answer 21

The vesicles contain neurotransmitters that are released in response to an action potential and diffuse across gap junctions
The neuronsecretory elements are then either recovered for future use or broken down

Question 22

Where is the enteric nervous system found

Answer 22

Found digestive tract form oes to rectum

Question 23

What are the two plexuses associated with the enteric nervous system

Answer 23

Myenteric plexus and submucosal plexus

Question 24

What are the nervous systems

Answer 24

Cns brain and spinal cord

PNS cranial nerves and spinal nerves