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Flashcards in week 1 Deck (61):
1

CSF

Filtrate of blood, made in the choroid plexus of the ventricles.
About 500ml produced each day. About 140 ml circulates throughout the subarachnoid space.
Offers mechanical and immunological protection to the brain and spinal cord. Reabsorbed into the venous drainiage of the head via the arachnoid granulations

2

Batson Veins (batson venous plexus)

connect the deep pelvic veins and thoracic veins to the internal vertebral venous plexuses. They are contained in the extra-dural space and provide a route of metastases from the deep pelvic region to the vertebral column or brain.

3

Artery of Adamkiewicz

Supplies the lower third of the spinal cord. Typically comes off the left posterior intercostal artery.
Important clinically because if the aortas is clamped during an aneurysm the artery can collapse, so must be perfused once the clamp is removed to prevent neurological deficit.

4

Epidural

not trying to puncture the dura so use a blunt needle

5

Lumbar puncture.

Done to withdraw CSF, measure the CSF pressure and to administer anti-biotics or chemo. Done at the level of L3/L4, or L4/L5. The supracristal line passes through the level of L4 and can be used as a guide.

6

A-alpha fibres

proprioceptors of skeletal muscle.
Lots of myelin, very fast conduction velocities

7

A-beta fibres

mechanoreceptors of skin (tactile sensation). Medium amount of myelin, fast conduction

8

A-delta fibres

pain and temperature. Little myelin - slower conduction

9

C fibres

no myelin, conduct slowly

10

Dorsal column- medial lemniscal pathway (tactile touch)

Projects up via the dorsal forniculus to the brainstem. Reaches the dorsal column nuclei in the medulla and decussates, having curved towards the midline as part of the internal arcuate fibres. Ascend via the medial lemniscus to the thalamus

11

Spinothalamic

Fibres decussate at the level of the spine. Fibres are a-delta or C.
Ascend in the antero-lateral funiculus

12

Corticobulbar

axons project to the cranial nerve nuclei in the brainstem

13

Corticospinal

axons project to the motor nuclei in the spinal cord

14

Broca's Area

Responsible for the motor aspect of speech. Located in frontal lobe

15

Wernicke's area

auditory association cortex: sensory language area and lexical processing. Temporal lobe

16

Corpus striatum

caudate, putamen, globus pallidus

17

striatum

caudate and putamen

18

lentiform nuclei

putamen and glbus pallidus

19

corpus callosum

major connection between the two cerebral hemispheres

20

Pain

An unpleasant sensory and emotional experience associated with actual or potential tissue damage

21

nociception

neural mechanism by which an individual detects the presence of a potentially tissue harming stimulus.

22

free-nerve endings

pain and temperature

23

merkel's disc

touch - mechanical deflection

24

meissner's corpuscle

touch - light touch

25

pacinian corpuscle

vibration

26

ruffini's endings

stretch

27

dermatome

region of skin supplied by a single spinal nerve

28

Neurogenic inflammation

The nociceptor releases neurotransmitters (substance P and CGRP) which induce vasodilation and plasma extravasation, as well as activation of many non-neuronal cells such as mast cells and neutrophils, contributing to inflammation seen

29

Action potential

A very brief, but dramatic change in membrane potential. All or nothing response. The depolarisation is linked to increased permeability to sodium ions

30

equilibrium potential

the membrane potential where the number of sodium ions entering the cell is equal to the number leaving the cell.
Nernst equation is used to calculate

31

Lidocaine

local anaesthetic which is a Na voltage-gated antagonist

32

excitatory post-synaptic potential

brings the post-synaptic potential closer to threshold, increasing the probability of post-synaptic cell producing an action potential (Na influx)

33

Temporal summation

where a single neuron fires multiple times and these impulses can summate to reach the threshold required to generate an action potential

34

Spatial summation

where the signal arrives from multiple sites, allowing the receiving neuron to reach its threshold and achieve an action potential

35

Neural networks can be convergent or divergent

Divergence - allows one neuron to communicate with many other neurons in a network
Convergence - allows a neuron to receive input from many neurons in a network

36

where does the supra-cristal line pass through?

the body of L4. The plans lies at the iliac crest

37

neuroblasts

primitive nerve cells

38

mantle layer of the future spinal cord

the future grey matter - location of the neuroblast cell bodies

39

marginal layer of the future spinal cord

future white matter. Contains the nerve fibres emerging from the neuroblasts in the mantle layer

40

basal plates

ventral thickening of the future spinal cord

41

alar plates

dorsal thickening of the future spinal cord

42

sulcus limitans

boundary between the basal and alar plates

43

what type of cells do the meninges develop from?

mesenchymal and neural crest cells

44

what does the prosencephalon become?

the telencephalon and diencephalon

45

what does the mesencephalon become?

the mid-brain

46

what does the rhombencephalon become?

the metencephalon and the myelencephalon

47

telencephalon will become

cerebrum

48

diencephalon will become

thalamus, hypothalamus, eye cup

49

metencephalon will become

pons and cerebellum

50

myelencephalon will become

medulla oblongata

51

where do the motor nerve fibres develop from, and when they do they begin to appear

develop from the nerve cell bodies located in the ventral horn.
Appear in week 4

52

where do the sensory nerve fibres develop from?

originate from the dorsal root ganglia, growing towards the periphery and the dorsal horn of the spinal cord.
Then start to grow into the dorsal horn of the spinal cord

53

cell types that the meninges develop from
when do they develop

mesenchymal and neural crest cells
days 20-35

54

Hydrocephallus

where there is a build-up of CSF in the head/brain. This causes compression of the brain due to build-up of spinal fluid in the ventricles
Treated with a shunt

55

what other symptoms are likely to be visible in Horner's syndrome?

Anhydrosis of the affected side of the face

56

two medical conditions that would cause the R external jugular vein to be distended in a patient

R. sided heart failure
Hodgkin's lymphoma - swollen lymph nodes
Pancoast tumour

57

thoracic duct

terminal duct of the lymphatic system - located at the junction between the left subclavian vein and internal jugular vein

58

structures passing through the thoracic inlet

apices of the right and left lung
brachiocephalic
subclavian arteries and veins
trachea
oesophagus
vagus, sympathetic trunk, phrenic nerves
brachial plexus

59

endoneurium

myelin sheath of each axon is wrapped in delicate protective sheath known as the endoneurium

60

perineurium

axons targetting the same anatomical location in a nerve as bundled together into fasicles. These are surrounded by a protective sheath know as the perineurium

61

epineurium

covering layer of several fasicles that are bundled together. May be bundled with a blood supply and fatty tissue