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Flashcards in Nerve Deck (20)
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1
Q

Name the four lobes of the brain

A

Frontal (front)
Occipital (back)
Temporal (temples)
Parietal ( middle)

2
Q

What are the ridges and valleys of the brain called?

A

Ridges – Gyri, Valleys - Sulci

3
Q

What are the three parts of the brainstem?

A

Midbrain – Pons - Medulla

4
Q

What is the cerebellum responsible for?

A

Fine tuning motor functions

5
Q

What are the four broad types of cells in the nervous system? (Named based on their appearance)

A

Unipolar: one axonal projection
Pseudounipolar: a single projection that splits into two
Bipolar: two projections
Multipolar: numerous projections

there is always only one AXON
the other projection is dendrites

6
Q

What are the three types of multipolar cells?

A

Pyramidal : pyramid shaped
Golgi : cerebellum
Purkinje : cerebellum

7
Q

What are the three main parts of a neurone?

A

Soma (cell body), axon (only one), dendrites (numerous)

8
Q

What is the difference between axons and dendrites?

A

Axons are myelinated and dendrites are not

There is only one axon but there are many dendrites

9
Q

What are astrocytes and what do they do?

A

astrocytes are very abundant and able to proliferate

Astrocytes are glial cells that have these functions:

  • Facultative macrophages (turn into macrophages when they need to)
  • Repair (provide nutrients for repair of neuronal cells)
  • Homeostasis (mop up neurotransmitter and other substances released by the CNS)
10
Q

What do oligodendrocytes do?

A

They myelinate many axons in the CNS

11
Q

What are some differences between oligodendrocytes and astrocytes?

A

Oligodendrocytes are:
Smaller
Denser cytoplasm and nucleus
Absence of intermediate filaments and glycogen in the cytoplasm

12
Q

What do microglial cells do?

A

They are the immune cells of the CNS

13
Q

What do ependymal cells do?

A

the epithelial cell that lines the CSF vesicles and regulates production

14
Q

What is the usual resting membrane potential?

how is it maintained ?

A

Between -40 and -90mV

the membrane is impermeable to ions so it is maintained by channels and pumps

15
Q

What are the intracellular and extracellular concentrations of the four main ions involved in action potentials?

A

Na+ - inside: 10 outside: 140
K+ - inside: 150 outside: 4
Cl- - inside: 5 outside: 120
Ca2+ - inside: 0.1 outside: 2

16
Q

What is saltatory conduction?

A

Action potentials jump between adjacent nodes of ranvier (instead of cable conduction) and so it speeds up action potentials

17
Q

what do Schwann cells do?

A

they only myelinate one section of the axon

18
Q

how do action potentials work?

A
  • at the RMP VGSC and VGKC are closed and the membrane is impermeable
  • change in membrane leads to depolarization to -40 mV and VGSC opening causing influx and the full depolarisation to +40mV
  • at this points VGSC close and VGKC open
  • this K+ efflex leads to the hyperpolarisation of the cell
19
Q

how does repolarisation happen?

A
  • the sodium-potassium pump uses ATP to move 3Na out and 2 K in
  • this causes the potential to reduce down again
20
Q

what is synaptic transmission?

A

this is when action potentials open the VGCC causing a Ca2+ influx which leads to exocytosis of the vesicles so the neurotransmitters are released ad bing to the post synaptic membrane