WEEK 1: Pathology Part 1 [Doc Erf] Flashcards
immune cells that can eat the microbes that eat the CNS. resident immune cells in CNS
microglia
reversible process involving neuronal swelling, cytoplasmic expansion, eccentric position of nucleus
Chromatolysis
phagocytosis of neuronal debris by microglial cells
neuronophagia
Proliferate locally after injury leading to the formation of scar (gliosis)
Astrocytes
aggregates of amorphous, basophilic, rounded structures occurring during aging
corpora amylacea
regulate the fluid transfer between the cerebrospinal fluid and CNS
ependymal cells
Most common congenital malformation affecting the dorsal lumbosacral region of the vertebral column
spina bifida; May be caused by hypervitaminosis A or folic acid deficiency.
dilation of the spinal cord central canal
hydromyelia
tubular cavitation extending along the length of spinal cord; may not communicate with central canal
syringomyelia
communicating hydrocephalus is caused by: (3)
Defective absorption of CSF (most often)
o Venous drainage insufficiency (occasionally
o Overproduction of CSF (rarely)
Normal CSF production is
0.20-0.35 ml/min
Capacity of the lateral and third ventricles in a healthy person
20 mL
total volume of CSf in an adult
120-150 mL
normal flow of CSF?
From the choroid plexus to the lateral ventricles to the interventricular foramen of Monro to the third ventricle to the sylvian aqueduct to the fourth ventricle
o Then to the 2 lateral foramina of Luschka and 1 medial foramen of Magendie to the subarachnoid space
o Then to the arachnoid granulations to the dural sinus
o Finally, into the venous drainage.
2 types of cerebral edema
vasogenic and cytotoxic
type of cerebral edema originating from fluid leaking from blood vessels due to disruption of blood-brain barrier causing increased vascular permeability and fluid accumulating around cells
Vasogenic type
most common cause of vasogenic type of cerebral edema?
TBI
type of Cerebral edema that is :fluid accumulating within the brain cells as a result of injury to the membranes;
cytotoxic type
most common cause of cytotoxic edema?
cerebral ischemia
causes of brain edema (5)
Traumatic brain injury (TBI) • Ischemic strokes • Intracerebral hemorrhages • Infections (e.g., meningitis, encephalitis) • Tumors.
causes of increased ICP? (6)
Space-occupying lesions, e.g., tumor, abscess, intracranial hemorrhage, epidural hematoma, subdural hematoma
• Hydrocephalus e.g., space-occupying lesion obstructing normal CSF flow
• Cerebral edema e.g., ischemic stroke with vasogenic edema, hypoxic or ischemic encephalopathy
• Increase in venous pressure e.g., cerebral venous sinus thrombosis, superior vena cava or jugular vein thrombosis/obstruction
• Metabolic disorders e.g., uremic encephalopathy, hepatic encephalopathy
• Increased CSF flow production e.g., choroid plexus tumors.
Displacement of a portion of brain tissue from its normal position protruding into adjacent compartments or may even push out of the skull if there is an opening present
herniation
type of brain herniation : displacement of the cingulate gyrus under the falx cerebri due to uneven or one-sided expansion of the cerebral hemisphere
subfalcine (cingulate herniation)
type of brain herniation? occurs when the inner part (medial aspect) of the temporal lobe is pushed against the free margin of the tentorium cerebelli; can compress the brainstem
transtentorial herniation (uncinate)
type of brain herniation: occur when there is downward pressure centrally; may cause a bilateral uncal herniation meaning an uncal herniation on both sides.
central transterntorial herniation (central herniation)
type of brain herniation: displacement of cerebellar tonsils downward through the foramen magnum
tonsillar herniation
causes of spina bifida?
unknown; but May be associated with: • Medications (e.g., anticonvulsants) • Diabetes mellitus • Genetics (family history) • Obesity • Increased temperature (e.g., fever, hot tubs, electric blankets)
4 complications of spina bifida?
> meningitis d/t infections
hydrocephalus d/t increased cranial pressure
Physical and neurological problems (lack of normal bowel and bladder control, paralysis of the legs.
latex allergy
site of formation of CSF?
choroid plexus at the lateral ventricle
mechanism of formation of CSF? (2)
selective ultrafiltration of plasma;
active secretion by epithelial membranes
2 causes of non communicating hydrocephalus?
Narrowing of sylvian duct;
obstructing mass`
2 causes of communicating hydroceph:
increased production; decreased absorption
acquired causes of hydrocephalus? (5)
tumor meningitis infection hemorrhage TBI
Most common cause of vasogenic cerebral edema?
brain trauma
T/F? in cytotoxic edema of the brain, blood brain barrier is intact
T
most common cause of cytotoxic cerebral edema?
ischemia
T/F both forms of cerebral edema cannot co exist
F. they can
Pressure exerted on to the brain tissue by external forces
ICP
normal ICP in adults?
10-15 mmHg; 135-200 mm of water
Normal ICP in children?
3-7 mmHg
Normal ICP in infants?
1.5-6 mmHg
What is monro-kellie hypopthesis?
an increase in any one of the components causes a change in the volume of the other.
Initial adaptation of the brain to keep the ICP in normal range.
decreased CSF production
causes of inc ICP? (4)
cerebral edema, head injury, stroke/intracerebral hemorrhage, tumor
2 major complications of uncontrolled increased ICP?
inadequate cerebral perfusion;
Cerebral herniation
most common type of herniation?
subfalcine herniation - the cingulate gyrus of the frontal lobe
what typer of herniation displaces the basal nuclei and cerebral hemispheres downward
central transtentorial herniation
what is diplaced in uncal herniation?
medial edge of the uncus and the hippocampal gyrus
what is displaced in cerebellar herniation?
infratentorial herniation - tonsil of the cerebellum is pushed thru the foramen magnum and compresses the medulla, leading to bradycardia and respiratory arrest