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BDS1 - BAMS - Histology > Introduction to nervous tissue > Flashcards

Flashcards in Introduction to nervous tissue Deck (38)
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1

What is the function of nervous tissues

Carrying information throughout the body via electrical impulses

2

What is the function of the nervous system

To provide rapid and precise communication between different parts of the body via the action of nervous

3

What are the two main divisions of the CNS

brain
spinal cord

4

What are the divisions of the PNS

cranial nerves
spinal nerves

5

What are the cells of the nervous system

neurones
glial

6

What are neurons

They are nerve cells and are the main functional unit of the nervous system

7

What is the role of neurons

To send signals around the body

8

What are glial cells

support cells

9

What is the role of glial cells

They protect, provide nutrients and immune function to neurons

10

What is the basic structure of a neuron

Has dendrites and axons

11

What is the dendrite

highly branched cellular process which extends from a large cell body

12

What is the axon

extends from the large cell body
large and cylindrical
At the terminus, the axon branches into several smaller branches called terminal boutons

13

What do terminal boutons interact with

effector organs or another neuron in the pathway

14

What is the fundamental property of a neuron

excitability

15

Describe how messages are delivered in neurons

Action potential travels through the neuron, reaches the terminal boutons and chemical message is released
and then received by dendrites of the next neuron and then processed to trigger an action potential in that next neuron

16

What do neurotransmitters do

They mediate neuron to neuron communication but also act to deliver the message to receptors/effector organs

17

What are the differences in neuronal cells and usual cells

have a larger nucleus
have nissl bodies
numerous mitochondria
no centrioles

18

Why can neurons not be repaired

lack of centrioles mean not able to divide

19

What do axons do

They rapidly propagate signals from the cell body towards axon terminals - they are specialized to conduct action potentials

20

What does an axon with a large diameter mean

It can propagate action potentials more rapidly

21

What is myelination

Myelination greatly increases the axon conduction potential for neurons
It is carried out by support cells

22

What are the different glial cells in the CNS

ependymal cells
astrocytes
microglia
oligodenderocytes

23

What are the different glial cells of the PNS

satellite cells
schwann cells

24

What are ependymal cells

Make up specialized epithelium that fills ventricles of brain and CNS
cuboidal/columnar in shape
tightly bound adjacently
no basement membrane - long processes merge into underlying tissue instead
At surface have cilia and some microvilli which help moves spinal fluid

25

What are astrocytes

Highly branched
fill spaces between neurons
form the blood brain barrier
regulate the chemical environment

26

What are microglia

Phagocytic capacity
Derived from macrophages in response to tissue damage

27

What are oligodendrocytes

Predominant neuroglia of white matter
Forms myelin sheath around all CNS axons
Provide structural and metabolic support

28

What are schwann cells

form myelin sheaths around PNS axons
non myelinated axons are enveloped in cytoplasm of schwann cell
myelinated axons are gradually wrapped by the shawn cell membrane to create a myelin sheath

29

What are satellite cells

Flattened cells that cover the surface of neuronal cell bodies
Provide structural and functional protection

30

what is the cytoplasm of the cell body known as

perikaryon