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Flashcards in 6. Nerve Deck (41)
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1

Name the 4 lobes of the brain

Frontal
Parietal
Temporal
Occipital

2

What are the ridges and valleys of the brain called?

Ridges= Gyri
Valleys= Sulci

3

What are the 3 parts of the brainstem?

Midbrain
Pons
Medulla

4

Why is the brainstem important?

Its the target or source of all cranial nerves

5

What is the cerebellum responsible for?

Motor coordination
Balance
Posture

6

Where does the spinal cord descend from?

Medulla

7

Role of spinal cord

Conduit for neural transmission
Co-ordinates some reflex actions

8

What are the 4 broad types of cells in the nervous system?
(Named based on their appearance)

Unipolar: 1 axonal projection
Pseudo-unipolar: single axonal projection that divides into 2
Bipolar: 1 axon, 1 dendrite projection
Multipolar: 1 axon, many dendrites

9

What are the 3 types of multipolar cells?

Pyramidal
Golgi
Purkinje

10

Neurones

Excitable cells of CNS
Heterogeneous morphology
Non-dividing cells

11

What are the 3 main parts of a neurone?

Soma (cell body)
Axon (only 1)
Dendrites (numerous)

12

Describe the soma

Contains nucleus and ribosomes
Has neurofilaments for structure and transport

13

Although neurones can differ by morphology, all only have 1

Axon

14

Describe the axon

Long process (aka nerve fibre)
Originates from soma at axon hillock
Can branch off into ‘collaterals’
Usually myelinated

15

Describe dendrites

Highly branched
NOT myelinated
Receive signals from other neurons

16

What are neuroglia?

All cell types in CNS that aren’t neurones

17

What is the difference between axons and dendrites?

Axons are myelinated and dendrites are not
There is only 1 axon but there are many dendrites

18

Name 5 neuroglia

Astrocytes
Ogliodendrocytes
Schwann cells
Microglial cells
Ependymal cells

19

What is the most abundant cell type in the CNS?

Astrocytes

20

Functions of astrocytes

Structural cells
Cell repair
Immune cells and are considered ‘facultative macrophages’
Neurotransmitter release and re-uptake – help maintain homeostasis

21

Name 2 myelin producing cells

Ogliodendrocytes
Schwann cells

22

Describe ogliodendrocytes

Provide myelin for other axons
Variable morphology and function
Numerous projections that form internodes of myelin
In CNS
1 oligodendrocyte myelinates many axons

23

Describe Schwann cells

Produce myelin for peripheral nerves
1 Schwann cell myelinates 1 axon segment

24

Describe Microglial cells

Specialised cells - similar to macrophages
Perform immune functions in CNS

25

Describe Ependymal cells

Epithelial cells - line fluid filled ventricles
Regulate production and movement of cerebrospinal fluid (CSF)

26

What is the usual resting membrane potential?

Between -40 and -90mV

27

What are the intracellular and extracellular concentrations of the 4 main ions involved in action potentials?

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

28

Why is transport of the main ions regulated by channels and pumps?

Cell membranes are impermeable to these ions

29

Describe the uneven ion distribution which creates a potential difference across the cell membrane

High extracellular: Na+ & Cl-
Low extracellular: K+
High concentration gradient for Ca2+ (into cell)

30

What is the charge inside neuronal cells compared to outside?

Negative charge inside compared to outside