Dr. Martin's notes

Friday Sptember 23. 2016

Circulatory system- Day 1


Heart: The heart is a four chambered hollow musclar organ, lying between the lungs under the sternum and to the left of center. It is approximately the size of a person's fist. It is covered by a membranous coating, the pericardium

Blood enters from the vena cava into the right atrium, and goes through the tricuspid valve into the right ventricle. It then goes through the pulmonary valve into the pulmonary artery into the lungs. The blood is re-oxegenated in the lungs then is sent back to the heart via the pulmonary vein into the left atrium. It passes through the mitral (bicuspid) valve into the left ventricle, through the aortic valve into the aorta
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The major vessels off the aorta are the subclavian artery, the common carotid artery and the brachiocephalic. The aorta then decends into the abominal cavity and has branches that go to most of the internal organs.There are intercostal arteries also.It separates into two major vessels L&R common illiac a. and then goes through the pelvis down into the leg as the femoral artery. Blood returns through a venous system that is essentially the same as the arterial system.

The arms are served by branches of the subclavian and brachiocephalic, which form the brachial artery, and the radial and ulnar arteries.

Blood is filtered and cleaned through two systems, the portal system (in the liver) and the renal system (in the kidneys).