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The heart is the driver of the circulatory system, pumping blood through rhythmic contraction and relaxation. The rate of blood flow out of the heart (often expressed in L/min) is known as the cardiac output (CO). Blood being pumped out of the heart first enters the aorta, the largest artery of the body.
Stable angina is chest pain on exertion that improves with rest. Unstable angina is chest pain that can occur at rest, feels more severe, and/or last longer than stable angina. It is caused by more severe narrowing of the arteries. [9] Heart attack. A heart attack results from a sudden plaque rupture and formation of a thrombus (blood clot ...
When renal blood flow is reduced (indicating hypotension) or there is a decrease in sodium or chloride ion concentration, the macula densa of the distal tubule releases prostaglandins (mainly PGI2 and PGE2) and nitric oxide, which cause the juxtaglomerular cells lining the afferent arterioles to release renin, activating the renin–angiotensin–aldosterone system, to increase blood pressure ...
Cardiac physiology or heart function is the study of healthy, unimpaired function of the heart: involving blood flow; myocardium structure; the electrical conduction system of the heart; the cardiac cycle and cardiac output and how these interact and depend on one another.
Whereas the peritubular capillaries surround the cortical parts of the tubules, the vasa recta go into the medulla and are closer to the loop of Henle, [1] [2] and leave to ascend to the cortex. [3] [4] Terminations of the vasa recta form the straight venules, branches from the plexuses at the apices of the medullary pyramids.
Coronary anastomoses are a clinically vital subject: the coronary anastomosis is the blood supply to the heart. The coronary arteries are vulnerable to arteriosclerosis and other effects. Inadequate supply to the heart will lead to chest pains or a heart attack (myocardial infarction). These can be ameliorated by surgical intervention to create ...
In other words, a juxtamedullary nephron is a nephron whose renal corpuscle is near the medulla, and whose proximal convoluted tubule and its associated loop of Henle occur deeper in the medulla than the other type of nephron, the cortical nephron. The juxtamedullary nephrons comprise only about 15% of the nephrons in the human kidney.
Failure of oxygen delivery caused by a decrease in blood flow in front of increased oxygen demand of the heart results in tissue ischemia, a condition of oxygen deficiency. Brief ischemia is associated with intense chest pain, known as angina. Severe ischemia can cause the heart muscle to die from hypoxia, such as during a myocardial infarction ...