Sat jul 25 Flashcards
what is the most abundant amino acid in collagen?
glycine
entacapone MOA
COMT inhibitor that blocks the peripheral conversion of levadopa, thus increasing its bioavailability
carbidopa MOA
DOPA decarboxylase inhibitor
what type of hypersensitivity reaction is post strep glomerulonephritis?
type III
During excercise, sympathetic discharge leads to vasoconstriction in arterioles of all tissues, except for the….
muscles - these dilate thus increasing their blood flow
which types of muscle have t tubules?
striated - cardiac and skeletal
what are t tubules and what is their function?
they are invaginations of the sarcolemma that transmit depolarization signals to sarcoplasmic reticulum to trigger the release of calcium and induce muscle contraction
—the uniform distribution allows the myofibrils to contract at the same time, in a uniform contraction
Decreased numbers of functional t tubules may result in…
uncoordinated muscle contraction which manifests as muscle weakness
tactile stimulation of the carotid sinus while standing, leading to syncope, is characteristic of …
carotid hypersensitivity
explain the pathophys of carotid hypersensitivity and how it leads to syncope
The carotid sinus detects a change in blood pressure and activates the parasympathetic nervous system and reduces sympathetic tone
- some individuals (esp older men) may have exagerrated sensitivity to tactile sensations, leading to an exaggerated vasovagal response
how will a capillary hemangioma (juvenile hemangioma) change over time?
they will first grow with the child but will eventually regress (with most regressing completely)
explain the reasons why elderly people are at high risk of developing heat-related illness
- they have tonic contraction of peripheral vasculature, limiting heat transfer to skin
- they have reduced sweat gland density
- they have loss of rete pegs and dermal capillaries, reducing the epidermal area available for heat transfer
febuxistat MOA
inhibits xanthine oxidase
pegliticase and rasburicase MOA
convert uric acid to allantoin- more soluble
symptoms of IVC obstruction + left side flank mass, suggests :
RCC that has extended through the renal vein to the IVC
how do Angiotensin effect the glomerulus?
constrict the efferent arterioles
how does alpha 1 stimulation effect the glomerulus?
constrict the affarent arteriole
how do prostaglandins effect the glomerulus?
dilate the affarent arteriole
where do B cells proliferate during an immune response?
in the follicles (germinal centres) of the lymph node - here they undergo isotype switching
where do you most commonly find a glioblastoma multiforme?
cerebral hemispheres - occasionally at the midline
how do glioblastoma multiformes appear grossly?
necrotic and hemorrhagic
pulsus paradoxicus occurs most commonly in…
cardiac tamponade
Clinical signs of cardiac tamponade?
Jugular venous distention, hypotension, diminished heart sounds
Pulsus paradoxus
what causes roseola infantum?
HHV6
how does imaging of a pilocytic astrocytoma look?
well demarcated lesion wiht cystic and solid portions
where does medulloblastoma occur?
cerebellum
what does medulloblastoma look like on imaging?
solid lesion, may have accompanied hydrocephalus
pathophys of ITP
antibodies form against platelet receptors resutling in platelet destruction
what is topiramate
an anticonvulsant that decreases the frequency of migraines
what medications can be given as preventitives for migraines
Beta-blockers, TCAs, anticonvulsants (topiramate, valproate)
where does the opthalmic artery come off of?
the internal carotid artery
name the branches of the external carotid artery
Superior thyroid, Ascending pharyngeal, Lingual, Facial, Occipital, Posterior auricular, Maxillary and Superficial temporal arteries
