Unit 2: Cardiovascular System Flashcards
what are the 4 major roles of the cardiovascular system
to transport oxygen from the lungs to the tissues;
to transport carbon dioxide from the tissues to the lungs;
to transport nutrients from the digestive system to other areas in the body;
to transport waste products from sites of production to sites of excretion.
How many sections is the heart divided into? name them
4: right atria, left atria, right ventricle, left ventricle
What is the function of the atrias of the heart
recieve blood from organs and pump blood down to ventricles. they are the collecting chambers of the heart.
what is the overall functions of the two ventricles of the heart
pumping blood out from heart to rest of body and lungs
where does the right atria pump out blood to
lungs
where does the left atria pump out blood to
body (not lungs)
What is pulmonary circulation
right side of heart pumps deoxygenated blood into lungs
What is systemic circulation
left side of heart pumps oxygenated blood (from lungs) to rest of body
What is coronary circulation
system of vessels that supply blood to heart muscle itself
what is the muscle tissue that makes up the heart
myocardium
What is the pacemaker of the heart
the SA node
Explain the self-contraction of the SA node in the heart
inside cells there is an action potential. the inside of the action-potential is negative while the outside of the action-potential is positive. However, the heart has some leaky channels, that allow the spillage of sodium into the heart. When the inside reaches its threshold, all the gap junctions open and calcium is flooded into the hells. Calcium spreads throughout the heart, which causes a contraction.
Define syncytium
when single cell is stimulated to contract, it causes all other cardiac muscle cells to contract too
What is the heart rate monitored by
automatic nervous system
How does electricity in heart cause top-down contraction
electrical signal spreads through both atria, causing atria to contract from top down and forcing blood into ventricles. Then, the electrical signal passes from atria into ventricles. ventricles then contract
from bottom up, forcing blood into aorta and pulmonary arteries
What is an ECG and what does it do
measures electrical activity of heart
provides a graphical representation of electrical sequence of events that occur with each contraction of heart (draws each heart beat)
What is a myocardial infarction
A heart attack: when blood supply to a region of the myocardium is reduced or cut off for prolonged period of time, myocardium tissue will be damaged or die
What are the two phases of the cardiac cycle
diastole = phase of relaxation (heart is filling with blood)
systole = phase of contraction (heart contracts and ejects blood)
What propels blood to circulate within heart and body
dramatic changes in pressure