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
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C fibres
no myelin, conduct slowly
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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
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Corticobulbar
axons project to the cranial nerve nuclei in the brainstem
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Corticospinal
axons project to the motor nuclei in the spinal cord
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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
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Corpus striatum
caudate, putamen, globus pallidus
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striatum
caudate and putamen
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lentiform nuclei
putamen and glbus pallidus
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corpus callosum
major connection between the two cerebral hemispheres
20
Pain
An unpleasant sensory and emotional experience associated with actual or potential tissue damage
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nociception
neural mechanism by which an individual detects the presence of a potentially tissue harming stimulus.
22
free-nerve endings
pain and temperature
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merkel's disc
touch - mechanical deflection
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meissner's corpuscle
touch - light touch
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pacinian corpuscle
vibration
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ruffini's endings
stretch
27
dermatome
region of skin supplied by a single spinal nerve
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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
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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
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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
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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
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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
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what does the rhombencephalon become?
the metencephalon and the myelencephalon
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telencephalon will become
cerebrum
48
diencephalon will become
thalamus, hypothalamus, eye cup
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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