Cardiac 2 Flashcards
What is the heart
pump and Flow generator
Why is it important that the heart has an adequate reserve capacity?
So pump performance can be improved when needed
ex runaway increase heart [omp when scared
conduit vessels that transport blood rapidly and at high pressure away from the heart
Arteries
last small branches of the arteries that act to regulate flow through a capillary bed
Arterioles
a very thin-walled vessel that permits exchange of nutrients and waste products between blood and interstitial fluid
Capillaries
small vessels that drain blood from the capillary bed; join together to form veins
Venules
capacitance vessels that transport blood slowly and at low pressure towards the heart;
valves are present ensure unidirectional flow; stores blood for mobilization if needed
Veins
What 3 mechanisms are in place for the cardiovascular system’s circuit?
- Maintain adequate flow (valves, flow sensors, fluid reservoir sensors)
- Maintain adequate pressure (pressure sensors)
- Changing fluid volume (volume sensor)
Are arteries stiff or compliant?
Conduit or capacitance?
Stiff
Conduit
Are veins stiff or compliant?
Conduit or capacitance?
Compliant
Capacitance
What creates pressure in the circulatory system?
Force exerted by blood on an area of the vessel wall
Compliance equation for arteries?
Compliance = (Change in volume)/(change in pressure)
In systemic circulation, where is the highest mean pressure?
ascending aorta
In systemic circulation, where is the lowest mean pressure?
right atrium
Does the aorta expand or recoil during systole
(LV ejection/contraction)?
Aortic expansion
LV ejection
Does the aorta expand or recoil during diastole (LV filling)?
Aortic recoil
LV filling
Is oxygenated or deoxygenated blood bright red?
Oxygenated
In which vascular bed is the greatest pressure drop?
Arterioles (proximal to distal)
What is the key area for regulating pressure flow thru the capillary bed
& impacting pressure in the ascending aorta?
arterioles
What is the mean blood pressure for animals?
100 mm Hg
Does pulmonary circulation have high or low pressure compared to systemic circulation?
Low do not need so much pressure shorter distance
Can you summarize the circulatory system as consisting of
in series and in parallel circuits?
The systemic and pulmonary circulations are arranged in series; the organs in systemic circulation are arranged in parallel
What are the layers of the heart from touching blood to external in contact w pericardial fluid?
Endocardium
Myocardium
Epicardium
List the 4 heart valves in mammals and birds
Right atrium
Right ventricle
Left atrium
Let ventricle
Where is tricuspid valve located?
Where is mitral(bicuspid) valve
tri- between right atria and ventricle
bi-between left atria and ventricle
What does aortic valve separate?
what does pulmonic valve separate?
Aortic valve between ascending aorta and LV
Pulmonic valve between PA and RV
What connects papillary muscles to their atrioventricular valves?
Chordae tendinae
Is blood pumped through the heart continuously or intermittently?
Intermittently to allow enough time for diffusion to occur
Does increasing total cross-sectional area at capillary beds speed up or slow down the flow of blood?
Why is this significant?
Slows down
Allows for diffusion to occur
more area to occur
Describe the windkessel effect
Ascending aorta expands during blood ejection due to its elasticity & returns to normal when blood is not ejecting;
returning to normal assists the flow of blood away from the heart and toward the periphery;
There is a “reserve” of fluid that can be accessed for movement
If all the blood vessels in parallel are added together, which one of the following classes of vessel has the greatest net cross-sectional area and consequently the slowest rate of flow?
a) Ascending aorta
b) Conduit arteries
c) Arterioles
d) Capillaries
e) Venules
D
Which cardiac valves would a red blood cell pass through as it flows from the pulmonary artery through the lungs into the aorta?
a) Tricuspid (first) and pulmonary (second)
b) Pulmonary (first) and mitral (second)
c) Mitral (first) and aortic (second)
d) Aortic (first) and tricuspid (second)
Follow the pathway from pulmonary artery into the left atria then into left ventricle to aorta. What valves are there
C
Follow the heart pump
Blood comes in from the cranial and caudal vena cavas to the right atrium,
passes through the tricuspid valve to the right ventricle.
Right ventricle contracts, valves close so blood cant reverse.
Blood then out through pulmonic valve into pulmonary artery to lungs.
From lungs oxygenated to left atrium,
goes through the mitral(bi) valve into left ventricle.
Goes out aortic valve and out ascending aortic arch to body
