BIOM20002 Lecture Notes - Lecture 55: Two-Dimensional Nuclear Magnetic Resonance Spectroscopy, Blood Pressure, Stroke Volume
Document Summary
Sympathetic constriction of arterioles, angiotensin and vasopressin augmenting vasoconstriction. 1 + 2 maintains perfusion pressure to vital organs: heart, brain, kidneys. Increases cardiac output but pressure is still far too low. Poor perfusion: not enough blood getting to organ. Can maintain normal bp even after losing 30% of blood since it is compensated by fast heart rate. Effect of transfusion (can be blood or electrolyte solution) Blood transfusion replaces lost oxygen-carrying capacity of blood. An understanding of these symptoms requires an understanding of the function of the aortic valve, coronary circulation and oxygen supply/ demand of the heart muscle. Diastole: mitral valve open, aortic valve closed, lv filling. Diastolic blood pressure maintained by elastic recoil of large arteries. Initial isovolumetric lv contraction: mv and av closed. Flow through coronary arteries depends on flow through aortic valve. Arterioles penetrate into heart muscle to supply oxygen (endocardial vessels) Occurs in the left ventricle during diastole only.
