Cardiovascular unit 1 Flashcards
How is the systemic circulatory system primarily arranged?
in parallel
Which vessel is the primary site of regulation of vascular resistance and blood flow?
arterioles. Remember they have the thickest layer of smooth muscle
What is the definition of microcirculation?
Defined as vasculature from first order arterioles to venules
How is the blood flow through capillaries determined?
Blood flow through capillary beds is determined by the pressure gradient, arterial and precapillary sphincters
Where does lymph rejoin the circulatory system?
subclavian veins
What is pericarditis?
inflammation of pericardium that restricts filling of heart
What is the diameter of the aorta?
25 mm = garden hose
what is the total blood volume?
5 L
where is the greatest blood volume in the circulatory system?
venous system
What is the biggest determinant of flow?
radius
What isoform is myosin in humans?
Beta –> slow ATPase
can be pathogenic
what isoform is tropomyosin?
alpha but can be pathogenic
**Skeletal has alpha AND beta
What is the function of titan?
Large protein that functions as an elastic spring in myosin
What are the two major isoforms of titan?
N2B and N2BA
What is the stiffer isoform of titan?
N2B: shorter
What is the less stiff isoform of titan?
N2BA: longer
What mediates preload?
thin filaments
TN-T: truncation increases Ca2+ sensitivity
TN-I - phosphorylation decreases Ca2+ sensitivity
What mediates afterload?
thick filaments
MYLC: myosin light chain
MYBPC: myosin binding protein C
What is the cardiac output at rest?
4-6 L/min
What is the main source of afterload for the left ventricle?
aortic pressure
What is the main source of afterload for the right ventricle?
pulmonary artery pressure
How does phosphorylation of phospholamban affect myocardium?
increase inotropy AND lusitropy
How does phosphorylation of L-type calcium channels and RyR channels affect myocardium?
increases inotropy
How does phosphorylation of troponin-I affect myocardium?
increases lusitropy
What are the two use dependent channel blocker drugs?
Class I and class IV
what is orthopnea?
increased shortness of breath when you lie down
when standing you have that increased blood pressure pooling at your legs with the help of gravity. When you lie down you lose the benefit of gravity and that extra blood can travel to right side of heart –> pulmonary system causing shortness of breath
what is paroxysmal nocturnal dyspnea?
delayed SOB waking patients up from sleep.
edema pooling in legs due to gravity. No longer have gravity working on your side
