nervous tissue

Question 1

what are the 2 categories called that nervous system cells can fall into

Answer 1

neuron

neuroglia (neural glue) cells

Question 2

describe neuron cells

Answer 2

nerve cell

specialised for signal conduction & information processing, and the relaying of the signal to a particular effector in tissue/organ

Question 3

describe Neuroglia (neural glue) cells

Answer 3

support, nourish & protect neurons

neuroglia are critical for maintaining homeostasis of interstitial fluid around neurons

Question 4

explain the structure of a typical motor neuron

Answer 4

Cell body
- nucleus, cytoplasm with typical organelles

Dendrites
- highly branched structures emerging from cell body – essential for receiving input, to carry out effect in body

Axon
- conducts impulse away from cell body toward another neuron or effector
- Emerges at cone-shaped axon hillock

Axon terminals
-at end of axon with synaptic bulbs, which are areas where connections formed with other cells within that system

Question 5

what do motor neurones do

Answer 5

conducting signal away from CNS and to peripheral of body

Question 6

Cells that exists within nervous system may be covered with what

Answer 6

myelin substance

Question 7

what is myelination

Answer 7

Axons covered with a myelin sheath

Question 8

describe what a myelin sheath is

Answer 8

Made up of Many layered lipid & protein creating insulations

They protect and support the axon

Increases speed of nerve conduction.

Question 9

what are Nodes of Ranvier

Answer 9

gaps in the myelin that aren’t myelinated

Question 10

what are nodes or ranvier important for

Answer 10

signal conduction

Question 11

what do some diseases do to axons covered in myelin sheath

Answer 11

destroy myelin,e.g. multiple sclerosis

Question 12

what is white matter made up of

Answer 12

primarily myelinated axons

Question 13

what is grey matter made up of

Answer 13

cell bodies,
dendrites,
unmyelinated axons,
axon terminals
& neuroglia (everything apart form myelinated axons)

Question 14

explain what the brain cortex is made out of

Answer 14

brain cortex = outer layer

made up of grey matter and white matter located internally. So myelinated axons that carry the info are internally

Question 15

explain the location of gray and white matter in the spinal chord

Answer 15

grey matter is centrally located and white matter is located externally

Question 16

nervous system tissues can be what types of matter

Answer 16

grey or white matter. This is du to actual colour of the cells

Question 17

Half the volume of cns is made up of what

Answer 17

neuroglia

Question 18

Unlike neurons the neuroglia do not have what function function

Answer 18

conducting impulses

Question 19

explain neuroglia cell size compared to neuron size

Answer 19

Neuroglia cells are smaller than neurons and can readily divide and multiply, so have capacity to fill brain areas from damage or disease to brain or nervous system. Neurons cannot do this. So is why we see long term affect of brain and spinal cord damage

Question 20

is the activity of neuroglia heterogeneous or homogeneous

Answer 20

heterogenous

and they have defined locations in nervous system

Question 21

explain how Neuroglia are migratory in nature

Answer 21

so act as phagocytes so have ability to consume waste products found in nervous system, defending the neural cells from debry waste and pathogens

Question 22

name the types of neuroglia

Answer 22

Astrocytes (star shape)

Oligodendrocytes

Microglia

Ependymal cells

Schwann cells

Satellite cells

first 4 are neuroglia only found in cns

Last 2 types of neuroglia are located in peripheral nervous system

Question 23

explain neuroglia Astrocytes (star shape)

Answer 23

blood brain barrier By wrapping around brain capillary’s, to protect nervous system from substance that are in blood

Form of connective tissue cell found in nervous system. And have important link between nerve cells and blood vessels.

Question 24

explain neuroglia
oligodendrocytes

Answer 24

create myelin in CNS

Question 25

explain microglia neuroglia

Answer 25

for defence

Question 26

explain neuroglia Ependymal cells

Answer 26

produce cerebrospinal fluid, that bathes the tissues of the nervous system

They form the membranes that line the areas of the brain known as cerebral ventricles, and they connect with the central canal of spine which also lines with ependymal cells

Question 27

explain neuroglia Schwann cells

Answer 27

PNS cell support/myelin. As form protective myelin sheath around myelinated nerve fibres

Also provide support for non myelinated cells as well

Question 28

explain neuroglia satellite cells

Answer 28

in PNS ganglia. Providing some support