Lecture 26 - Structure of the heart and conduction system Flashcards
What is the systemic circulation?
The systemic circuit transports oxygenated blood to virtually all of the tissues of the body and returns relatively deoxygenated blood and carbon dioxide to the heart to be sent back to the pulmonary circulation.
What is the pulmonary circulation?
The pulmonary circuit transports blood to and from the lungs, where it picks up oxygen and delivers carbon dioxide for exhalation.
Does the right ventricle pump deoxygenated blood or oxygenated blood?
The right ventricle pumps deoxygenated blood into the pulmonary trunk, which leads toward the lungs and bifurcates into the left and right pulmonary arteries. These vessels in turn branch many times before reaching the pulmonary capillaries, where gas exchange occurs: Carbon dioxide exits the blood and oxygen enters. The
How many valves are there and what are their functions?
Four. The left and right atrioventricular valves (AV) allow flow from the atria to the ventricles, but block reverse blood flow by flapping closed
What is the function of the left and right valve?
The left and right atrioventricular valves (AV) allow flow from the atria to the ventricles, but block reverse blood flow by flapping closed.
What is the function of the left and right semilunar valves?
The left and right semilunar valves (pulmonary and aortic valves) allow blood to flow from the ventricles into the arteries, but block return flow.
How many coronary vessels are there?
Two.
What are the functions of the left coronary vessel?
The left coronary artery gives rise to the anterior ventricular branch and the circumflex branch
What are the functions of the right coronary vessel?
The right coronary artery supplies the posterior side of the heart through a right marginal branch and a posterior interventricular branch.
What kind of muscle is the cardiac muscle and is it voluntary or involuntary?
Cardiac muscle is striated and autoergonic (self stimulating).
What are the cells in the muscle called? Describe their composition.
The individual cells are myocytes, but they are connected to each other through intercalated discs, which tightly join the myocytes together through desmosomes and also contain gap junctions for ion flow.
Which tissue does the cardiac muscle use to replace itself if damaged?
As a result, the entire heart is like one big muscle cell. It is impossible for cardiac muscle to repair itself and, when damaged, is simply replaced by fibrous tissue.
