Pathophysiology Flashcards
Most common nervous system cell type that support the endothelial cells that make up the BBB
astrocytes
Cells that are macrophages of CNS
microglial cells
What cells produce myelin?
oligodendrocytes
Part of neuron where impulses are generated and conducted down axon
axon hillock
What size fiber conducts faster?
larger diameter fiber conducts faster than small fibers
Where do action potentials occur on the axon?
only at the nodes of Ranvier increasing the velocity and conserving energy
Immune mediated inflammatory demyelinating disease of the CNS
multiple sclerosis
How many MS patients present with involvement of the optic nerve resulting in monocular visual disturbances?
1/4
Lhermitte’s sign (MS)
Tingling in the back and anterior thigh upon neck flexion
Uhthoff’s sign (MS)
Symptoms worsen when patient becomes heated
Degenerative disease of the basal ganglia involving the failure of dopamine-secreting neurons (substantia nigra)
Parkinson’s Disease
How many people over age 85 have AD?
almost half
Pathology restricted to cerebral cortex, hippocampus, amygdala, and another basal nucleus called nucleus of Meynert
Alzheimer’s Disease
Produces acetylcholine
nucleus of Meynert
Plaques characteristic of Alzheimer’s
amyloid
Which chromosome carries gene for amyloid protein?
- Almost all people with Down syndrome who live beyond 45 develop AD
autoimmune disease characterized by the presence of antibodies against the nicotinic ACh receptor which destroys them
Myasthenia Gravis
Characterized by encephalopathy and fatty changes in several organs, esp. liver
Reye’s Syndrome
abnormal discharge of electrical activity within the brain
seizure
episodes of widespread and intense motor activity
convulsion
recurrent disorder of cerebral function marked by sudden, brief attacks of altered consciousness, motor activity or sensory phenomenon.
epilepsy
type of seizure that is almost imperceptible alterations in consciousness
petit mal (absence seizures)
type of seizure with dramatic loss of consciousness, falling, generalized tonic-clonic convulsions of all extremities, incontinence, and amnesia for the event
grand mal (generalized tonic-clonic)
Group of brain neurons susceptible to activation.
Plasma membranes may be more permeable to ion movement. Firing of these neurons may be greater in frequency and amplitude
Epileptogenic focus
Why is edema a problem in the brain and spinal cord?
enclosed space, lack of lymphatics, lack of anastomoses in venous drainage
For what type of edema can you give IV bolus of hypertonic soln (mannitol) to draw water into the vasculatare and out of the brain?
cytotoxic
Type of edema that occurs when BBB is disrupted due to inflammation, toxic agents, neoplasm
vasogenic
Normal ICP
5-15 mmHg
Hallmarks of increased ICP
HA, vomiting, papilledema
Break in dura results in exposure of brain tissues to environment. Results in focal (localized) injury
Open (penetrating) trauma
injury to a nasal sinus that allows air into brain or ventricles - cerebrospinal rhinorrhea
Traumatic pneumocephalus
More common head trauma. Involves head hitting hard surface or rapidly moving object strikes head. Dura is intact
Blunt Head Trauma
head strikes against object. shearing forces cause small tears in blood vessels
coup
Typically located on the top of skull and act as an expanding mass
subdural hematoma
Usually frontal and temporal lobes and acts as expanding mass
intracerebral hematoma
Most common of all neurological problems
cerebrovascular disease
Artery that contains 70% of cerebral blood flow
internal carotid artery
What sign occurs with upper motor neuron lesion?
babinski sign (dorsiflexes and splays)
