BIPN 100 Lecture Notes - Lecture 17: Coronary Circulation, Cardiac Muscle, Circulatory System
This preview shows pages 1-2 of the document.
Unlock all 5 pages and 3 million more documents.
This preview shows pages 1-2 of the document.
Unlock all 5 pages and 3 million more documents.
Get access
Related Documents
Related Questions
Background:
It is a peculiarity of the cardiac circulation that there are channels thatpass from coronary arterioles, from the capillary bed,and from the cardiac veins directly into the lumen ofthe heart. Irregular thin-walled channelsof larger than capillary size, which are called"myocardial sinusoids," also receive blood from the coronary arterioles or the capillary bed andcommunicate with the smallest cardiac veins that opendirectly into the chambers of the heart, particularly into the atria. It has been assumed that the stream in these veins can be reversedand thus help in nourishing the ischemic myocardium incase of coronary obstruction. Some of theseopenings in the cardiac cavity can be seen with nakedeye by inspection of the endocardial lining. They vary from pinpoint size to almost 1 mm in diameter. |
Does the coronaryarterial system enter into communications with other arteries inthe neighborhood and if so, how do these arteries reach theheart?
How important are theyfor the supply of the ischemicmyocardium?