Nervous Tissue

Question 1

What system is nervous tissue an essential component of?

Answer 1

Nervous system

Question 2

What subgroups comprises the nervous system?

Answer 2

Central Nervous System (CNS) and Peripheral Nervous System (PNS)

Question 3

What are some functions of nervous tissue?

Answer 3

Maintains homeostasis (along with endocrine system)

Initiates voluntary movements

Perception

Behaviour

Memory

Question 4

List 3 types of neural activity

Answer 4

Sensory - detection of internal/external stimuli and transfer to CNS

Integrative - analysis and storing of information

Motor - stimulation of effectors (e.g muscles and glands) through PNS

Question 5

List the two neural cell types

Answer 5

Neurons (nerve cells)

Neuroglia (supportive cells)

Question 6

What is the structure of a neuron?

Answer 6

Cell body

Short branched dendrites - convey nerve impulses

Axon - conducts nerve impulses to another neuron or tissue

Question 7

List the 3 structural classifications of neurons

Answer 7

1. Multipolar
2. Bipolar
3. Unipolar

Question 8

List the structural features of a multipolar neuron and give an example of a multipolar neuron.

Answer 8

Several dendrites

One axon

All motor neurons (muscles) are multipolar neurons

Question 9

Describe the structure of a bipolar neuron and give an example of where a bipolar neuron may be found

Answer 9

One dendritic process (unbranded at cell body)

One axon

Cell body found between dendrite and axon

Special sense organs - sight, smell, hearing

Question 10

Describe the structure of a unipolar neuron and give an example of a unipolar neuron

Answer 10

Dendrites and axon continuous

Cell body off to the side

Most sensory nerves are unipolar neurons

Question 11

List the 3 functional classifications of neurons and the structural classification they’re associated with

Answer 11

Sensory (afferent) - unipolar
Motor (efferent) - multipolar
Interneurons - multipolar

Question 12

What are neuroglia?

Answer 12

Neural cells found in both the CNS and the PNS. Do not propagate action potentials/nerve impulses.

Question 13

List the 4 types of CNS neuroglia

Answer 13

1. Astrocytes
2. Oligodendrocytes
3. Microglia
4. Eppendymal cells

Question 14

What is the structure and function of an astrocyte?

Answer 14

Star shaped

Support

Contributes to blood brain barrier

Question 15

What is the function of an oligodendrocyte?

Answer 15

Forms myelin sheath around CNS axons via secretion. Can form multiple myelin sheaths from one cell.

Question 16

What is the function of microglia in the CNS?

Answer 16

Phagocytise, active immune defense in CNS

Question 17

What is the function of eppendymal cells in the CNS?

Answer 17

Production of cerebrospinal fluid

Question 18

What two types of neuroglia can be found in the PNS?

Answer 18

1. Schwann cells

2. Satellite cells

Question 19

What is the function of a Schwann cell in the PNS?

Answer 19

Wraps around axons to form myelin sheath. One cell per axon.

Question 20

What is the function of a satellite cell in the PNS?

Answer 20

Surrounds cell bodies

Support

Fluid exchange

Question 21

What are the similarities and differences between oligodendrocytes and Schwann cells?

Answer 21

Oligodendrocytes: found only in CNS, secretes myelin sheath around axons, capable of secreting sheaths for multiple axons

Schwann cells: found only in PNS, forms myelin sheath around axons by wrapping around it, one cell per axon

Question 22

Define dendrite

Answer 22

A short branched extension of a nerve cell

Question 23

Define axon

Answer 23

Long thread-like part of a nerve cell; impulses from cell body to other cells.