Correct Answers
Circulatory system is composed of ✅vessels, fluid, pump
Structures of circulation ✅arteries, arterioles, capillaries, venues, veins
Arteries vs veins ✅- Arteries have higher pressure, more muscle, less stretch
- Veins are low pressure (valves help bring blood back to heart, don't have much
muscle)
Blood flow ✅- depends on differences between pressure in the arterial and venous
vessels
Resistance ✅length and diameter of blood vessels, viscosity
Velocity ✅V decreases as blood moves from aorta to capillaries
Vascular compliance ✅volume the vessel can accommodate for a given increase in
pressure
Heart ✅- pumps 2.4 ox of blood per beat
- weighs about 1 lbs
- size of a fist
Left heart ✅- thick walled ventricle
- high pressure pump
- receives blood from lungs
- pumps to systemic circulation
Right heart ✅- thin-walled ventricle
- low pressure pump
- receives blood from systemic circulation
- pumps to lungs
Flow through chambers ✅Body> right atrium > right ventricle> lungs> left atrium> left
ventricle
Which is the only vein in the body that carries oxygenated blood? ✅pulmonary
Which is the only artery that carries deoxygenated blood? ✅pulmonary
, Structures that direct circulation through the heart ✅pericardium
Myocardium
Endocardium
Pericardium ✅- protects against inflammation and infection
- prevents displacement of the heat
- pain receptors, elicit changes in BP and HR
Myocardium ✅- thickest layer
- cardiac muscle
Endocardium ✅- internal lining of myocardium
- connects with arteries, capillaries, and veins to create continuous closed system
Cardiac cycle ✅1. Diastole: atria fill, all valves closed
2. Diastole: increased atrial pressure opens AV valves, ventricles fill
3. Systole begins: atria contract and empty, ventricles are full
4. Systolel ventricles begin contraction, pressure closes AV, aorta relax
5. Systole: ventricles contract, increase pressure in ventricles, aortic and pulmonary
valves open, blood ejected into aorta and pulmonary artery
6. Diastole: ventricles empty, ventricles relax, aortic and pulmonary valves close
Right coronary artery ✅- conus: supplies R upper ventricle
- right marginal branch: supplies R ventricle
- posterior descending: supplies to smaller branches of both ventricles
Left coronary artery ✅- Left anterior descending: supplies left and right ventricle
- circumflex artery: supplies left atrium and lateral wall of left ventricle
Coronary blood flow is higher during.. ✅diastole than during systole
- determined by pressure gradient
- diastole: 2/3 resting
- systole: 1/3 contracting
Collateral circulation ✅- some arterial anastomoses exist within circulation
- when occlusion occurs slowly over a period of time, there is a change of collateral
circulation to develop
Myocardial metabolism ✅- cardiac muscle depends on ATP
- used for muscle contraction and relaxation and electrical excitation
Cardiac output ✅- volume of blood ejected by a ventricle in 1 min: normal adult is
5L/min
- cardiac output= hrxsv