Cells of the Nervous System

Question 1

The central nervous system (CNS) consists of…

Answer 1

two cerebral hemispheres, the brainstem, the cerebellum and the spinal cord

Question 2

The peripheral nervous system (PNS) consists of…

Answer 2

the nerve fibres originating from the CNS.

Question 3

Frontal lobe function

Answer 3

Responsible for executive functions such as personality

voluntary movement, expressive language and for managing higher level executive functions.

Executive functions refer to a collection of cognitive skills including the capacity to plan, organise, initiate, self-monitor and control one’s responses in order to achieve a goal

Question 4

Parietal

Answer 4

Contains the somatic sensory cortex responsible for processing tactile information

One involves sensation and perception and the other is concerned with integrating sensory input, primarily with the visual system.

Question 5

Temporal

Answer 5

Contains important structures such as the hippocampus (short term memory), the amygdala (behaviour) and Wernicke’s area (auditory perception & speech)

Question 6

Occipital

Answer 6

Processing of visual information

Question 7

The brainstem consists of

Answer 7

the midbrain, pons and the medulla

Question 8

what order

Answer 8

descending order

midbrain highest
medulla lowest

Question 9

cerebellum function

Answer 9

motor coordination, balance and posture.

Question 10

Unipolar cells

Answer 10

1 axonal projection

0—-0

Question 11

Psuedo-unipolar

Answer 11

Single axonal projection that divides into two
0
0—-1—-0

Question 12

Bipolar

Answer 12

2 projections from cell body

0—–0—–0
1 axon
1 dendron

Question 13

Multipolar

Answer 13

Numerous projections from cell body

Question 14

how many axons and dendrite

Answer 14

only 1 is axon rest is dendrite

Question 15

types of multipolar

Answer 15

Pyramidal cells
Purkinje cells
Golgi cells

Question 16

what is the cell body known as and what does it contain

Answer 16

Soma, perikaryon
nuclues and ribosomes
Neurofilaments

Question 17

what are Neurofilaments

Answer 17

structure & transport

Question 18

what is an axon

Answer 18

single projection from cell body/originates from soma at axon hillock

Can branch off into ‘collaterals’

Question 19

what are they covered in

Answer 19

Usually covered in myelin

Question 20

structure in dendrites

Answer 20

Highly branched cell body

Question 21

are they covered in myelin

Answer 21

NO

Question 22

function

Answer 22

Receive signals from other neurons

Question 23

most abundant cell in mammilian brain

Answer 23

Astrocytes

Question 24

function

Answer 24

structural cells and are known to play an important role in cell repair, synapse formation, neuronal maturation and plasticity.

Question 25

what are oligodendrocytes

Answer 25

are the myelin producing cells of the CNS,

Question 26

Schwann cells

Answer 26

same function in the PNS.

Question 27

differences

Answer 27

oligodendrocyte is capable of myelinating a number of axons a Schwann cell only myelinates a single axonal segment.

Question 28

Microglia function

and similarty to what other cell

Answer 28

microglial cells are specialised cells that are similar to macrophages and they perform immune functions in the CNS

Question 29

Ependyma function and what sort of cell

Answer 29

epithelial cells that line the fluid filled ventricles regulating the production and movement of cerebrospinal fluid.

Question 30

what are the major physiological ions in cns

Answer 30

potassium
sodium
chloride
calcium

Question 31

are the cell membranes permeable to those

Answer 31

• impermeable to these ions  transportation regulated by channels & pumps

Question 32

what conc is highest outside the cell

Answer 32

Na+ & Cl-

Question 33

highest inside

Answer 33

K+

Question 34

where is calcium greatest

Answer 34

extracellular

Question 35

what is the resting potential inside the cell

Answer 35

-50 to -90

= -70mv

Question 36

which channels are closed closed

Answer 36

Voltage-gated Na+ channels (VGSCs

voltage-gated K+ channels (VGKCs

Question 37

Membrane depolarisation change

Answer 37

• opening of VGSC  Na+ influx  further depolarisation

Question 38

membrane repolarisation

Answer 38

VGKCs opens at a slower rate and causes  efflux of K+ from cell

Question 39

why is sodium open faster

Answer 39

it is faster to open

Question 40

last dip in graph

Answer 40

hyperpolarisation

Question 41

how is it restored back

Answer 41

sodium potassium pump

Question 42

what sort of movement

Answer 42

active, na pumped out

k enters

Question 43

next

Answer 43

na k pump back to resting state- na enters

k leaves

Question 44

what is Saltatory conduction

Answer 44

ap can jump across areas of no myelin

faster

Question 45

what does mylein do

Answer 45

prevents AP spreading because it has - high resistance & low capacitance

Question 46

Nodes of Ranvier

Answer 46

• Small gaps of myelin intermittently along axon:

Question 47

The synapse position

Answer 47

is a junction consisting of a pre-synaptic nerve terminal
separated from the postsynaptic cell
by an extracellular space known as the synaptic cleft

Question 48

nuerotrasnmition at a synapse

Answer 48

Propagation of the action potential (AP)
AP is propagated by VGSCs opening
Na+ influx  membrane depolarisation  AP ‘moves along’ neurone
VGKC opening  K+ efflux  repolarisation

Question 49

next part

Answer 49

AP opens voltage-gated Ca2+ channels at presynaptic terminal
Ca2+ influx  vesicle exocytosis

Question 50

and then

Answer 50

NT dissociates from receptor and can be:
Metabolised by enzymes in synaptic cleft
Recycled by transporter proteins

Question 51

lastly

Answer 51

NT binds to receptors on post-synaptic membrane

Receptors modulate post-synaptic activity

Question 52

what happens to teh nt

Answer 52

broken down by enzymes and enters back into pre synaptic terminal c

enzyme not always needed, it can enter back into the pre synamitic terminal directly