Flashcards in 2. Neurophysiology Deck (102)
How does Mg prevent excitotoxicity in brain?
Blocks Ca and NMDA channels
Most abundant excitatory neurotransmitter in the brain?
Cellular elements of BBB
Capillary endotheilal cells connected by tight junctions
Platelet function after SAH?
Enhanced leading to increased platelet aggregation in cerebral microcirculation
Cerebral blood flow immediately after SAH?
What is GPIIb/IIIa?
Platelet surface integrin - mediator of platelet aggregation
Dense granules of platelets?
5HT, ATP, PDGF
Disturbed balance of which peptide contributes to vasospasm?
Endothelin 1 (vasoconstriction) and nitric oxide (vasodilation)
Superoxide and hydrogen peroxide generates highly reactive hydroxyl radical - name?
Mechanism of steroid treatment in blunt spinal cord injury?
Local blood flow, inhibition of immunologic injury, and free radical-mediated lipid peroxidation and neuronal damage
What is S100B?
Calcium binding protein abundant in astrocytes - may be neuroprotective/neurotrophic
What is Windkessel phenomenon?
Cerebral vasculature expand and ability of CSF/venous blood to translocate to accomodate arterial pulsations and provide smooth capillary flow in the brain
Region where cerebral blood flow reduction has passed threshold that leads to failure of electrical but not membrane function - structurally intact, but functionally disturbed
Role of infiltration with local anesthetic at beginning of a case?
Prevents activation of nociceptors during surgery and lessens need for analgesics
Structural unit of gap junction
Connexon allows direct electrical communication between cells
Functions of TGF beta?
Development/progression of brain tumors
What enzyme is inhibited by acetazolamide?
Difference between bioactive Guglielmi detachable coil (GDC) and platinum GDC?
Bioactive coil accelerates clot and promotes development of mature connective tissue
Mutation in Crouzon syndrome
Fibroblast growth factor receptor 2 - absence of ligand binding - premature fusion of cranial sutures leading to abnormal cranium shape, restricted growth and increased ICP
Chaotic, high amplitude EEG (Infantile spasm)
Loss of vertebral column heigh with aging
Genetic defect in Gorlin syndrome?
Mutation of PTCH gene that predisposes to neoplasias and widespread congenital malformations
Water channel proteins of the brain?
Most common agent for pharmacologic dilatation of vasospastic cerebral vessels?
Papaverine hydrochloride - endothelium-independent smooth muscle relaxant
How do intervertebral disks receive nutrition?
Passive diffusion from capillary beds in subchondral endplate region of vertebral body
Composition of PEEK cage
Polyetheretherketone (PEEK) spacers - strong polymer that withstand compressive load of vertebral column
Common areas of leptomeningeal dissemination for tumors
Basilar cisterns, sylvian fissure, cauda equina (gravity and slower rate of CSF)
Resting membrane potential in myelinated pheripheral nerves? in soma?
~ 90 mV and ~ 65 mV
Determined by K+ (100x more permeable than Na+)