Lectures 5-8: Neuroanatomy

Question 1

astrocytes =

Answer 1

type of glia…

cellular extensions interact with synapses and blood vessels

control composition of extracellular space to allow neuronal function

form scar tissue after injury

Question 2

microglia =

Answer 2

type of glia…

brain macrophages

clear infections and debris

Question 3

oligodendrocytes =

Answer 3

cellular extensions form insulating myelin sheath around axons to allow rapid nerve impulse conduction

Question 4

most abundant type of cell body in the corpus callosum…

Answer 4

corpus callosum = white matter therefore is composed of myelinated axons = no neurons…

oligodendrocytes

Question 5

local current is influenced by…

Answer 5

difference between active and resting potential

Question 6

myelin sheath -

Answer 6

increases membrane resistance and decreases capacitance

Question 7

node of ranvier -

Answer 7

where ion channels are located

membrane resistance low compared to inter-node

action potential moves by salutatory conduction from node to node, is propagated between nodes by electronic conduction

Question 8

evidence that current flow occurs at nodes of ranvier…

Answer 8

• current stimuli needed to reach potential threshold is less if locally applied rather than inter-nodes
• local application of anaesthetic to block conduction is more effective at nodes than inter-nodes

Question 9

voltage clamp =

Answer 9

measures current flowing through ion channels

a feedback amplifier supplies current to rapidly return membrane potential to a chosen level

Question 10

myelination in CNS -

Answer 10

by oligodendrocytes

myelinate several inter-nodes

Question 11

myelination in PNS -

Answer 11

schwann cells

myelinate a single inter-node

Question 12

myelination creates..

Answer 12

distinction between white and grey matter in the brain

Question 13

ganglion =

Answer 13

collection of neurons in PNS

Question 14

nucleus =

Answer 14

collection of neurons in CNS

Question 15

nerve =

Answer 15

a bundle of axons in PNS

Question 16

tract =

Answer 16

collection of CNS axons with a common site of origin and destination

Question 17

motor neurons concentrated …

Answer 17

ventrally (belly/front)

• motor fibres activate muscle for movement

Question 18

sensory fibres concentrated …

Answer 18

dorsally (back) and in head

• input info from environment

Question 19

fore-brain =

Answer 19

cerebral cortex
basal ganglia
thalamus
hypothalamus

Question 20

hind-brain =

Answer 20

cerebellum
pons
medulla oblongata

Question 21

brain stem =

Answer 21

midbrain
pons
medulla

Question 22

spinal cord…

Answer 22

covered by meninges - pia, arachnoid, dura

and irrigated by cerebrospinal fluid - produced by filtration of blood, circulates through spinal canal and the subarachnoid space

Question 23

the brain …

Answer 23

protected by skull and meninges and irrigated by cerebrospinal fluid

Question 24

rostral =

Answer 24

noseward (anterior)

Question 25

caudal =

Answer 25

tailwards (posterior)

Question 26

ventral =

Answer 26

belly/front/underneath

Question 27

dorsal =

Answer 27

back/on top

Question 28

dermatone =

Answer 28

a region of skin innervated by dorsal roots from one spinal segment

Question 29

white matter =

Answer 29

ascending and descending myelinated and unmyelinated axons

Question 30

grey matter =

Answer 30

contains neuronal cell bodies

Question 31

hypothalamus =

Answer 31

head ganglion of the autonomic nervous system secretes vasopressin and oxytocin via posterior pituitary gland releases hormones to induce secretion of hormones from anterior pituitary gland

Question 32

motor unit

Answer 32

an alpha motor neuron and the group of muscle fibres it innervates

Question 33

two types of neural lesion/ dysfunction :

Answer 33

1) white matter = interrupted axnol conduction | 2) grey matter = death of neurons

Question 34

syndromes affecting white or grey matter -

Answer 34

spine/head injury stroke infection e.g meningitis neural tumour

Question 35

diseases primarily affecting white matter:

Answer 35

multiple sclerosis ( CNS inflammatory demylination) paraplegia (distal degeneration of spinal cord) neuropathy ( distal demyelination of peripheral nerve)

Question 36

diseases primarily affecting grey matter

Answer 36

motor neuron disease (spinomuscular atrophy) cerebellar diseases basal ganglia diseases (Huntington's, Parkinson's) temporal/frontal lobe diseases (Alzheimer's, dementia)