Cardiovascular System Flashcards
What are the 3 main functions of the cardiovascular system?
- transportation
- protection
- regulation
What section of the heart can you not see when looking in to the chest cavity?
L atrium
What covers the heart?
from outer to inner
- fibrous layer and parietal pericardium
- pericardial cavity
- visceral pericardium
- myocardium
- endocardium
Explain the direction of blood from superior and inferior vena cava to body
- Superior/inferior vena cava to R atrium
- through the tricuspid/R atrioventricular valve to the R ventricle
- through the pulmonary semilunar valve to the pulmonary trunk
- splits in to the R/L pulmonary arteries
- to the pulmonary arterioles and in to the lungs
- to the pulmonary veins and in to the L atrium
- through the biscuspid/L atrioventricular valve to the L ventricle
- through the aortic valve and in to the aorta
Why are ventricles thicker than atria? Which is thickest?
Because they have to pump blood out of the heart and atria are basically just reservoirs; thickest is L ventricle
How are the AV and semilunar valves opened/closed?
passive process based on pressure difference across valves; heartbeat is associated with valves opening
What is the fossa ovalis?
hole in the R atrium that closes when born b/c pressure drops in lungs and closes flap over it
Where are the pectinate muscles found?
in both atrium
What are the heart strings and what do they do?
chordae tendineae- attach from papillary muscles to valves in the ventricles and prevent prolapsing, but do not help close valves
What makes up the muscle walls of the heart?
trabeculae carneae
What are the 3 types of circulation?
- systemic: carries blood from heart to body and back
- pulmonary: carries blood from heart to lungs and back
- coronary/cardiac: supplies blood to the heart itself
Why do we have L/R coronary arteries above the aortic valve and off the aorta?
- the aortic valve closes the left/right coronary artery so the high blood pressure doesn’t destroy the little coronary arteries
- the pooled blood when the aortic valve closes and drops down goes in to the coronary arteries
How is blood flow controlled in capillaries? Where are they found in abundance?
- controlled by precapillary sphincters (they contract when you are relaxed because you don’t need as many nutrients and relax/open when you are active)
- abundant in tissue that is metabolically active
Difference between arteries and veins?
- more veins than arteries
- veins are reservoirs and arteries are suppliers
- veins are thinner w/ valves
- veins have lower pressure
What are the three processes that help veins return blood to the heart?
- venous valves keep blood from going backward
- arteriovenous coupling - a pulsewave in the artery can push the blood towards the heart
- contracted skeletal muscles can push blood towards the heart
