Cardiovascular systems

• The circulatory system of mammals is an efficient closed, double loop system where deoxygenated and oxygenated blood are kept in separate circuits
• This system is powered by an efficient, four-chambered heart pump
• The muscular development of the ventricles in the heart, especially the left ventricle, also generates a blood pressure high enough to move blood with force and speed through all the blood vessels.
• Cardia or coronary circuit is where the travel of blood within the heart muscle happens
• Pulmonary circuit is the path of bood from the heart to the lungs and back.
• Systemic circuit is the path of blood from the heart to the rest of the body.
• 3 types of vessels which make up a blood circulatory circuit are: the artery, the vein, and the capillary.
• Arteries carries blood away from the heart.
• Arteries have a thick layer of smooth muscle, making them elastic. It also has smaller inner diameter than viens
• Capillaries- thin walled: consist of single surrounding layers of epithelial cells
• Capillaries connects arteries and veins
• Veins: carries blood toward the heart
• veins are thin walled, have greater internal diameter and less elasticity
• veins have valves which prevent back flowing of flood
• SA node, natural pace maker in geaer
• AV node contracts based on SA node signals
• Continuous contraction is controlled within the heart itself, where a bundle of specialized muscle tissue is found in the right atrium. The area is called sinoatrial node
• Contractions and relaxations begin at the S-A node and spread across the heart muscle.
• Electrical stimulus and contraction move from S-A node to an AV node, area between atria and ventricles
• After a short period of relaxation the process of contractions are repeated
• The control center is medulla, at the base of the main brain.
• Some examples of body controls which can modify natural heart rates include: High CO2 concentration, stretch receptors in the muscle walls of right atrium, sudden stress and strong emotions which triggers hormones such as adrenalin.
• The medical name for heart attack is myocardial infarction.
• Myocardial infraction means death of tissues of myocardium or heart muscle due to constricted blood flow
• A heart attack, at simplest, is a lack of oxgyen
• Here how heart attack happens: ruptured cholesterol plaque flow by a clod clots narrows then blocks blood flow in an artery, then the blockage deprives heart of oxygen rich blood, without blood and oxygen heart muscles start dying. Which leads to an electrical malfunction that the heart sops pumping, sending paitent into cardiac arrest.
• A patient with suspected heart attack uses an EKG monitor to check the electrical activity of the heart.
• Doctors test blood for troponin, and proteins that the heart muscle releases when damaged for patients suspected of heart attack
• Research shows that for next 90 days, patients that suffered from heart attack are at an increased risk of another cardiac event.
• The average 4-6 liters of blood in a human adult is made up of: Nutrients and wastes, hormones, and blood cells
• Blood fluid can make its way through capillary walls into tissue spaces and around cells. This liquid forms the lymph or interstitial fluid surrounding the cells and collecting in body cavities.
• The liquid portion of blood could be refined further into what is called a serum.
• The serum portion of blood contains no blood cells, and has no clotting agents or proteins
• Since a large portion of the fluid is water, which is a good solvent, many nutrients and wastes are simply dissolved in it.
• Hormones are chemical messengers produced by the ductless glands in various parts of a body.
• Plasma is albout 90% water, without red or white cells
• The remaining 10% of plasma are nutrients
• Plasma contains various proteins which can help with clotting, or act as an immune function
• Red blood cells are the most numerous of the blood cells
• The red blood cells look dished in, which allows them to bend and maneuver through the confined spaces of the capillaries