Chap 28 Key Concepts Flashcards
(50 cards)
What is a feature of injury in the nervous system?
There is a distinct set of patterns of response to the injur
What are the characteristics of neuronal injury?
- Cell death by apoptosis or necrosis
- Loss of neurons (difficult to detect)
What is the morphology of an injured astrocyte?
- Hypertrophy of the cytoplasm
- Accumulation of intermediate filament protein (GFAP)
- Hyperplasia
What are microglia?
Resident monocyte-lineage population of the CNS
How does microglia react in response to injury?
Proliferate and accumulate
What is cerebral edema?
Accumulation of excess fluid within the brain parenchyma
What is hydrocephalus?
Increase in CSF volume within all or part of the ventricular system
What can raise the pressure inside the fixed capacity of the skull?
Increases in volume of the intracranial contents Ex. increase of CSF volume Ex. edema Ex. hemorrhage Ex. tumor
How does increase in pressure relate to perfusion?
increased pressure can cause decreased perfusion which leads to ischemia
How do herniations occur?
increased pressure displaces tissue past the edges of dural partitions inside the skull or through openings in the skull
What can cause malformations in the CNS?
Single gene mutations, larger scale genetic alterations, exogenous factors
What stage of development is a malformation likely to be most severe?
The earlier in development of a malformation, the more severe
How does a neural tube defect occur?
Failure to close or inappropriate reopening of the developing neural tube
How does cortical development occur?
Proper progenitor cell proliferation in germinal matrix and migration of progenitors upward into developing cortex
What is the result of disruption of cortical development?
Alters size, shape and organization of the brain
Why is time so critical in a perinatal brain injury?
The earlier events cause greater damage and deficits
What is cerebral palsy?
Non-progressive deficits with injury during the prenatal and perinatal periods
How does physical injury to the brain occur?
When inside the skill comes into forceful contact with the brain
When and how do coup and countrecoup injures occur?
- Occurs with blunt trauma
- If the head is mobile, there is injury at the original point of contact (coup) and on the opposite side of the brain (countrecoup)
How do parenchymal injuries occur?
In the form of a contusion with hemorrhage extending into the subarachnoid space
How does diffuse axonal injury occur?
Rapid displacement of the head and brain that tears the axons
What can traumatic tearing of blood vessels cause?
Epidural and subdural hematomas
What is a stroke?
Clinical term for acute-onset neurologic deficits resulting from hemorrhagic or obstructive vascular lesions
When does cerebral infarction occur?
- Following the loss of blood supply
- Can be widespread or local or affect regions with the least robust vascular supply
