Flashcards in Pathology Deck (58)
What are common causes of acute neuronal injury?
What is the descriptive term used for neurones affected by acute neuronal injury?
How soon after the acute injury do "Red Neurones" appear?
On examination what do the neurones post injury look like?
Shrinking and angulation of nuclei
Loss of nucleolus
How do axons appear post injury?
Swelling of the cell body and nucleolus.
Degeneration of axon and myelin sheath distal to the injury.
Chronic Degeneratie neuronal atrophy appears how?
Shrunken small dark nuclei
How do oligodendrocytes react to injury?
Loss of myelin sheath
Conduction is reduced
Axons are exposed to injury
What are oligodendrocytes susceptible to?
Oxidative stress e.g hypoxia
Astrocytes undergoing scar formation and repair can be described as undergoing what?
How does early gliosis appear?
How does late gliosis appear?
Shrunken and dark lying within a dense mass
What are ependymal cells susceptible to?
Limited reaction to injury
Usual site of tumour formation or infection
How do microglia appear on inspection?
Form aggregate around area of necrotic or damaged tissue.
M2 - Microglia
Anti inflammatory phagocytic cells - More Acute
M1 - Microglia
Pro Inflammatory more chronic
List some common causes of Hypoxia.
What proportion of the bodies intake of oxygen is used by the brain?
By how many times can cerebral blood flow increase to match the demand before supplies of ATP are used up?
What s excitotoxicity?
Energy Failure- Hypoxia or hypoglycaemia
What is the Pathophysiology behind excitoxicity?
Neuronal depolarisation and re-uptake of transmitters inhibited.
Glutamate is released and builds up.
Ca2+ build-up proteases activated.
Mitochondria dysfunction and oxidative stress.
List the types of oedema affecting the brain.
Causes of Cytotoxic oedema
Causes of Ionic oedema
Excess water intake
Causes of Vasogenic oedema.
Breakdown in the BBB
Trauma Tumour Inflammation
How does a breakdown in the BBB result in vasogenic oedema?
Plasma proteins and insoluble proteins able to cross, water follows via osmosis.
Global Cerebral ischaemia is due to.
Generalised reduction in blood flow - Hypovolaemic shock cardiac arrest
Focal Cerebral Ischaemia is due to.
Which areas are most susceptible to ischaemia?
Zones between two arterial territories.