Tutor profile: Krystl O.
Subject: Health and Medicine
What is Ischemia?
Ischemia is decreased or absent blood flow that results in hypoxia ( low oxygen levels at the tissue level). Causes: Examples: 1. Decreased arterial flow 1. Artherosclerosis 2. Decreased venous outflow 2. Hepatic Venous Thrombus 3. External Compression 3. Compartment Syndrome The pathophysiology of Ischemia Decreased Oxygen levels result in decreased ATP synthesis. Decreased Oxygen level results in less Oxygen present to be the final electron acceptor in Oxidative -Phosporatlation leading to the generation of free radicals. These free radicals cause damage to membranes such as the mitochondrial membrane leading to damage of the mitochondria and cessation of ATP production. Without ATP, N/K ATPase pump can not function. Thus Na (sodium) can not be pump out of the cell and accumulate inside the cell. Water follows cause lysis of the cell and death. If this continues on a large scale with many cells, thus affecting tissue, and progression to the entire organ. This will result in organ failure and death.
What is the Cori Cycle?
The Cori Cycle is the way that the body manages the accumulation of lactate in the body. Lactate is a by-product of anaerobic metabolism, meaning the metabolic pathways that take place in the absence of Oxygen. When there is no Oxygen, Pyruvate, the end product of Glycolysis can not continue into the Kreb's Cycle and the Electron Transport Chain to synthesize ATP. Thus the body will use Pyruvate to make Lactate. The generation of Lactate ensures that Glycolysis will continue with the production of a small amount of ATP. This is done by Lactate Dehydrogenase (LDH). The conversion of Pyruvate to Lactate also regenerates NAD+ which is needed for Glycolysis. This pathway is great because it generates ATP but this pathway is bad because it produces a large amount of lactate. Think about your muscles when you are running and they begin to become sore. This is the lactate that is responsible for the soreness. The body must rid itself of lactate. This is done by the Cori cycle where lactate is removed from the muscle cell and transported to the liver where the lactate is generated into pyruvate. The pyruvate undergoes glyconeogenesis and made into Glucose. This glucose then leaves the liver into the bloodstream and transported back to the skeletal muscle to be used in Glycolysis.
What is the anatomy of the heart?
The heart's function is to provide blood flow to the entire body. This blood flow allows for the transport of vital nutrients to the body such as glucose and oxygen for cellular respiration. Thus the anatomy of the heart reflects this function. The heart can be seen as a dual pump, made of the right heart and left heart. The right heart pumps blood into the pulmonary circulation and the left heart into the systemic circulation. The heart is a huge muscle that has a covering. The muscle is called the myocardium. The inside of the heart has a layer called the endocardium and the outside of the myocardium is called the epicardium. The heart is enclosed in a sac called the pericardium. The heart is made of up values that allow the blood flow to go forward only if functioning properly. The names of the valves are the aortic, pulmonary, tricuspid, and mitral. The pulmonic and tricuspid valve are on the right side of the heart and the aortic and mitral are on the left side of the heart. The heart also is composed of inner chambers. The atria are the receiving chambers and the ventricles are the pumping chambers. The heart has many blood vessels coming to and from it. The Superior Vena Cava and inferior Vena Cava bring deoxygenated blood from the body to the Heart. And the Aorta pump out this new fresh oxygenated blood the the entire body. The Pulmonary trunk transport deoxygenated blood to the lungs to receive fresh oxygen. The heart is supplied by coronary arteries. The main coronary arteries are the Left and Right Coronary Artery. There are sub-branches of these arteries that supply the entire heart.
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