Exam 1 Review:  Chapter 18:  Major Vessels

aorta - The largest of the elastic = conducting arteries which have a thick tunica media with much elastic tissue layered between the smooth muscle layers; the main trunk of the systemic arteries, carries oxygenated blood from the left side of the heart to the arteries of the head, the trunk, the limbs and to all organs except the lungs.

systemic arteries - The aorta and all its branches which carry oxygenated blood from the left side of the heart to the capillary beds of the head, trunk, limbs and all organs except the lungs.

pulmonary trunk - The second largest of the elastic = conducting arteries; the main trunk of the pulmonary circulation, carrying deoxygenated blood from the right side of the heart to the arteries of the lungs.

ductus arteriosus - One* of the normal fetal shunts, allowing blood to bypass circulation to the lungs; since the fetus does not use his/her lungs (oxygen is provided through the mother’s placenta), flow from the pulmonary circulation needs to be diverted; the ductus arteriosus provides this, transferring flow from the left pulmonary artery to the aorta just beyond the origin of the artery to the left subclavian artery; the high levels of oxygen to which it is exposed after birth causes it to close in most cases within 24 hours; when it does not close, it is termed a Patent Ductus Arteriosus.  (*The foramen ovale and the interventricular shunt are the other two.)

ligamentum arteriosum - The fibrous connective tissue band which runs between the superior surface of the origin of the left pulmonary artery and the inferior surface of the arch of the aorta and represents the closed remnant of the fetal ductus arteriosus.

vena cavae - The largest pair of veins in the systemic circulation, carrying deoxygenated blood from the head and arms (superior vena cava) and the trunk, and legs, and from all organs except the lungs and the heart itself (inferior vena cava) to the right side of the heart.

pulmonary arteries - The pulmonary trunk and all its branches which carry deoxygenated blood from the right side of the heart to the capillary beds of the lungs.

pulmonary veins - The right and left pulmonary veins and all their branches which carry oxygenated blood from the capillary beds of the lungs to the left side of the heart.

coronary circulation - The movement of blood through the myocardium of the heart by means of the coronary arteries (the first branches of the aorta) and their branches, the capillaries of the myocardium, and the coronary veins and their branches, which empty into the coronary sinus before returning the blood to the right atrium.

coronary arteries - The system of muscular blood vessels which delivers oxygenated blood from the left ventricle to the capillary beds of the myocardium; they are the first pair of branches off the ascending aorta.

coronary veins - The system of thin-walled blood vessels which returns deoxygenated blood from the capillary beds of the myocardium to the coronary sinus before returning the blood to the right atrium.

coronary sinus - The short dilated channel on the posterior (dorsal) surface of the heart which opens into the right atrium of the heart and serves to return deoxygenated blood from the coronary veins to the right atrium.

anastomoses - Any vascular channels which permit intercommunication between two or more vessels, e.g., the cross communications between two arteries or two veins; such connections permit blood flow in either direction and serve to provide additional blood supply or drainage to a particular structure, tissue, or capillary bed; such connections lessen the risk of tissue damage or death if one of the connecting vessels becomes obstructed.  (Also a union or joining of nerves or lymphatic vessels.)

collateral circulation - Blood flow to or from a region of tissue served by blood vessels which form anastomoses; blood flow when established through indirect or subordinate branches when the supply through the main vessel is obstructed

Describe:

3. the coronary circulation.

 

The coronary circulation is the set of vessels which permits movement of blood through the myocardium of the heart by means of the coronary arteries (the first branches of the aorta) and their branches, the capillaries of the myocardium, and the coronary veins and their branches, which empty into the coronary sinus before returning the blood to the right atrium.