sample exam Flashcards
A broad band Doppler reading is indicative of what type of flow?
turbulent (vessel disease) vibration,not normal
In most tissue beds blood flow is regulated in proportion to?
local metabolism
the vascular compartment with the greatest total cross sectional area is?
capillaries
Which of the following is NOT characteristic of parallel circuitry?
maximizes total peripheral resistance
IS: flow control, decrease work load of heart, max oxygen to tissues
A small change in volume producing a large change in pressure is characteristic of which vascular compartment?
systemic arteries
ACH binding to the vascular epithelium has what effect?
vasodilation by causing NO release
what is the effect of sympathetic nervous stimulation on most vascular smooth tissue?
vasoconstriction mediated by ALPHA receptors
during widespread SNS stimulation which tissue bed would show the least increase in vascular resistance
lung
As a tissue becomes more acfive, how is blood flow to that tissue increased?
tissue release local vasodilators
at a given circulatory filling pressure what happens to venous return as CVP increases?
Decreases
CVP up=VR down
If cardiac output is stopped, arterial pressure will be expected to fall until it equals?
critical closing pressure or CVP
in a healthy young adult comment about tissue flow during diastole
maintain the recoil of the arteries
what increases the plasma colloid osmotic effect by about 50%
negative changes to protein attracting, and holding positive ions like sodium
which effects is NOT attributed to slow breathing? (6 breaths/min)
increased sympathetic activity
what effect does decreasing velocity have on blood viscosity?
Increase
How does fibrinogen decrease blood viscosity?
makes RBCs flexible
The chronic use of anti inflammatory drugs could be expected to inhibit?
Angiogenesis
which brainstem area is tonically active and is associated with a tonic SNS outflow?
neurons anterolateral in the upper medulla and pons (pressor)
anterolateral in lower medulla: depresser
nucleus tractus solitorius: lower BP CN 9 10 mediates
which substance is associated with local vasodilation?
Adenosine
Angiotensin II: stim ADH, thirst in hypothalamus
what high resistance micro vessels control local blood flow by integrating multiple input which determine lumine diameter?
arterioles
which may act at the level of the CNS in the development of hypotension or (bradycardia)
Nitric oxide (lowers BP, increase anti ox..)
in the kidney, how does SNS stimulation increase angiotensin formation?
stimulation of JG cells to release renin
in response to fall in systemic arterial blood pressure which changes would be counterproductive in offsetting the fall?
Increase in ANP release or Decrease SNS stimulation
in the face of rising arterial blood pressure ,which would autoregulate both renal blood flow and glomerular filtration?
constriction of afferent arterioles (decrease both)
efferent: decreases renal Q
what does stimulation of baroreceptor have on sympathetic outflow?
Decrease
during systole (exercise) what is happening to baroreceptor activity?
increasing, arteries are distended
in the fetus, the ductus arteriosis shunts blood from the pulmonary artery to the aorta returning primarily from what vessel?
superior vena cava
inferior vena cava: foramen ovale
umbilical veins: ductus venous to IVC
what is the function of the ductus venosus in the fetus?
shunt blood from umbilical vein into the IVC
In which tissue bed does SNS stimulation cause a metabolically induced local increase in blood flow?
Heart
active skeletal muscle: increase blood flow, adenosine, CO2, K+, histamine, lactic acid
during exercsie, which normal decrease?
VO2
during exercise most of the increase in cardiac output is due to ?
increased heart rate
