A) The Atrioventricular Valves (A-V valves)

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1 The Mammalian Heart : -Located in the thoracic or chest cavity under the ribs and sternum between the two lungs -Surrounded by a protective sac called the pericardium -It is made up of cardiac muscle (that contracts repeatedly without fatigue, and contain many mitochondria). -The mammalian heart is divided into 4 chambers: a) right atrium b) right ventricle c) left atrium d) left ventricle -The top chambers are the atria (singular: atrium) which receive blood from the lungs and body and pump blood to the ventricles. -Atria have thinner walls than ventricles, they don t need to create as much force. -The bottom chambers, or ventricles have a thick muscular walls and are the pumping chambers that push blood out through the blood vessels and into the capillary beds of the pulmonary, or systemic circulation systems. -The septum is the thick muscular wall that separates the right and left ventricles. -A series of valves prevent blood from flowing the wrong way in the cardiac cycle. A) The Atrioventricular Valves (A-V valves) 1) Tricuspid valve is located between the right atrium and right ventricle. It contains 3 cusps. 2) Bicuspid valve is located between left atrium and left ventricle. It has two parts or cusps. B) Semilunar Valves 3) Aortic semilunar valve is located at the entrance of the aorta as blood exits the left ventricle. 4) Pulmonary semilunar valve located at the entrance of the pulmonary artery as the blood exits the right ventricle. Defective Heart Valves -Improper closing of heart valves causes a backflow of blood at certain times during the heartbeat cycle -Produces an abnormal heart sound known as a heart murmur Flow of Blood Through Heart: -The superior vena cava returns deoxygenated blood from the upper portion of the body and the inferior vena cava returns deoxygenated blood from the lower body and legs. -This blood enters the right atrium. -When the atria contract, blood flows from the right atrium through the atrioventricular valve

2 (tricuspid) into the right ventricle. -The ventricles contract and the heart pumps blood out into the lungs through the pulmonary artery (via the pulmonary sumilunar valve) -Oxygenated blood returns to the heart from the lungs through pulmonary veins that enter the left atrium. -The atria contract and again the atrioventricular valve (bicuspid) opens and blood flows from the left atrium to the left ventricle. The ventricles contract and the left ventricle pumps blood through the aorta to the systemic circulatory system via the aortic semilunar valve. NOTE : Lub dup of heart beat is created by A-V valves quieter lub and then the louder dup of semilunar closing after ventricle contraction.. Diseases of the Circulatory System Hypertension, commonly know as high blood pressure. -More pressure is exerted on the arteries if more volume of blood is being moved, or the arteries lose their elasticity. -Diets high in cholesterol cause the arteries to become clogged, making he heart exert more pressure to move the blood. -Diets high in salt, cause the body to retain water, which increases the volume of blood. This also increases blood pressure. -High blood pressure often occurs alongside... Atherosclerosis is a condition caused by cholesterol buildup on the inner walls of arteries. -It causes the heart to work harder when pumping blood through the less elastic arteries.. -Artherosclerosis in the arteries leading to the heart muscle itself, it can lead to a heart attack. -Artherosclerois in arteries to the brain can cause strokes. Arteriosclerosis is caused when fatty tissue deposits on the lining of the arteries. -The blockage can cause damage to platelets, which will trigger the formation of a blood clot. -The blockage can prevent blood flow and cause tissue to die. -The clot may also break free (aka embolism), and travel to the heart or brain causing serious damage. Coronary Blockage The heart itself is supplied with oxygen rich blood via the coronary arteries (part of the cardiac circulation). These arteries can develop plaques that impede blood flow. If the plaque ruptures, blood clots may form. This will lead to angina while at rest, or a heart attack. When the heart is not receiving enough oxygen, chest pain called angina develops.

3 Treatments Bypass Surgery A vein from another part of the body can be sewn in above and below the blockage point in the artery so that blood bypasses the blocked spot. If the patient has more than one blocked artery, then a double, triple or quadruple bypass surgery is performed. Angioplasty Angioplasty is a general term used to describe a procedure for treating such blockages and/or blood clots. The procedure involves the use of thin, wire mesh lined balloons and other devices that are threaded through a blood vessel in the groin and into a coronary artery. The balloon is inflated to squash the blockage or blood clot and stretch the artery open, restoring normal blood flow. (Se fig 9.28 pg 326) Medicines Medicines can also be used to break up blood clots. Aspirin is often prescribed because it prevents platelets from sticking together, thereby reducing clot formation. Prevention An ounce of prevention is worth a pound of cure. -Eat a low fat, low cholesterol, low salt, well balanced diet. -Exercise regularly. -Have your blood pressure and cholesterol checked to ensure they are in the normal range.

4 Name: Blood Typing 1 A person s blood type depends upon the presence or absence of two special proteins, called antigens A and B, on the surface of the red blood cell 2 n individual is born with antibodies against red blood cell antigens that his or her blood does not have 3 Antibodies are proteins formed within the blood that react with antigens to remove them. e.g. blood type A has antigen A on the RBC but contains anti-b antibodies in the plasma Major Blood Types TYPE ANTIGEN ANTIBODIES A A Anti-B B B Anti-A AB A and B none O none Anti-A, Anti-B Blood Transfusions Blood type is important in blood transfusions and organ transport. If a person gets the wrong blood type the antibodies in his or her plasma will react with the antigen on the RBC of the donor and will agglutinate ( clump) Blood vessels may become block eventually leading to death. To see if agglutination will occur follow these steps: 1) Identify the recipient and the donor 2) Find the antibodies of the recipient 3) Find the antigen of the donor 4) If the agglutinin of the recipient and the antigen of the donor are the same, agglutination/clumping will occur and therefore a transfusion cannot take place To Clump or Not to Clump? Fill in the table below, with clumping or no-clumping Recipient Blood Type O A B AB Donor Blood Type O A B AB Based on the table above, fill in the blanks below: Universal Donor is blood type Universal Recipient is blood type

5 Complete the Blood Transfusion Chart Type Antigen Antibody Receive from Give to A B AB O Rh Factor A protein found on the RBC that was first discovered in rhesus monkeys early ~85% of humans have the Rh factor on their RBCs and are said to be Rh+, the other 15% lack the Rh factor and are said to be Rh- Rh Factor & Blood Transfusions A person with Rh+ blood can receive both Rh+ and Rh- blood. A person with Rh- blood can only receive Rh- blood. If given Rh+ blood the recipient s blood plasma produces anti-rh antibodies causing the blood to agglutinate. Recipient Rh+ Rh- Rh- Donor Rh+ Rh Factor and Pregnancy Rh Factor can be a problem if a pregnant woman has Rh- blood and the baby is Rh+. The Circulatory systems of mother and baby are usually independent of one another; however, there is sometimes a small mixing of blood during birth. The mother s blood plasma will produce anti-rh antibodies to fight the foreign Rh+ protein. This doesn t happen during first pregnancy but on subsequent pregnancies the anti-rh antibodies from the mother s blood can enter the baby s blood and destroy its Rh+ blood cells. Treatment This problem can be eliminated if the Rh- mother is given an injection of anti-rh antibodies called Rho Gam shortly after the birth of each Rh+ child. These antibodies destroy any Rh antigens on the baby s blood cells that have entered the mother s circulatory system. The mother s immune system does not have to produce anti-rh antibodies and there is no problem with the next Rh+ baby