BIOL 1002 Exam 3 Learning Objectives Dr Scott Crousillac Spring 2014 Chapter 32 Circulation Understand the 3 basic parts of all circulatory systems and the main functions of each A pump the heart that keeps the blood circulating A liquid blood that serves as a medium of transport A system of tubes blood vessels that conduct the blood throughout the body Understand the functions of the human circulatory system 1 Transporting oxygen from the lungs to the tissues and transporting carbon dioxide from the tissues to the lungs 2 Distributing nutrients from the digestive system to all body cells 3 Transporting waste products and toxic substances to the liver where many of them are detoxified and to the kidneys for excretion 4 Distributing hormones from the glands and organs that produce them to the tissues on which that act 5 Regulating body temperature by adjustments in blood flow 6 Wound healing and blood clotting to prevent blood loss 7 Protecting against disease by circulating white blood cells and antibodies Understand how the human heart differs from fish amphibian and reptile hearts The hearts of fish the 1st vertebrates to evolve consist of two chambers a single atrium that empties into a single ventricle having two atria and one ventricle Some fish turned into amphibians who then evolved into reptiles who have a three chambered heart The four chambered hearts of some reptiles including crocodiles and their relatives and all birds and mammals have separate right and left ventricles that completely isolate oxygenated and deoxygenated blood Understand the circulation terminology Artery vessel that carries blood away from the heart Vein vessel that carries blood to the heart Pulmonary anything dealing with the lungs Systemic having to do with everywhere else in the body Vena Cava largest vein in the human body Aorta largest artery in the human body Be able to trace the flow of blood through the mammalian heart including all valves involved Right atrium Atrioventricular valve right ventricle semilunar valve pulmonary artery lungs pulmonary vein left atrium Atrioventricular valve left ventricle semilunar valve aorta body Understand the difference between systolic and diastolic pressure and what causes each Systolic pressure the higher of the two readings is measured during ventricular contraction Diastolic pressure is the minimum pressure in the arteries as the heart rests between contractions Be able to trace the flow of the electrical signal throughout the heart and all of the structures involved Electrical impulses coordinate the sequence of heart chamber contractions o The contraction of the heart is initiated and coordinated by a pacemaker a cluster of specialized heart muscle cells that produce spontaneous electrical signals at a regular rate o The heart s pacemaker is the Sinoatrial node located in the upper wall of the right atrium o Electrical signals from the SA node pass freely into the connecting cardiac muscles cells and then throughout the atria The electrical signal then passes from the right atrium to a specialized group of muscle cells between the right atrium and right ventricle called the Atrioventricular AV node o From the AV node the signal to contract spreads along specialized tracts of rapidly conducting muscle fibers called the Atrioventricular bundle Av bundle which sends branches to the lower portion of both ventricles o Here the bundles branch further forming Purkinje fibers that transmit the electrical signal throughout the ventricle Sinoatrial node pace maker top of the right atrium Atrioventricular node the valve between atrium and ventricles Atrioventricular bundle AV bundle or bundle of his Delays contraction of ventricles Allows time for atria to contract completely and fill ventricles with as much blood as possible Purkinje fibers Understand the purpose of the AV nodal delay It allows time for the atria to contract completely and the ventricles to fill up completely with as much blood as possible Understand the major components of both the plasma portion and cellular portion of blood and their functions Plasma comprises about 55 of total blood volume The cell based portion which as about 40 45 of total blood volume consists of red blood cells white blood cells and platelets Plasma is primarily water in which proteins salts nutrients and wastes are dissolved o Proteins are the most abundant dissolved molecules by weight and include Albumin which helps to maintain the blood s osmotic strength Globulins which are antibodies that play and important part in immune response Fibrinogen which is important in blood clotting The cell based components of blood are formed in bone marrow o Blood contains three cell based components red blood cells white blood cells and platelets but only the white blood cells are complete functional cells Mature red blood cells are not actual cells because they lack a nucleus which is lost during development o All three components originate from blood stem cells that reside in the bone marrow Stem cells are unspecialized that can divide to produce offspring capable of maturing into one or more types of specialized cells Red blood cells carry oxygen from the lungs to the tissues o About 99 of all blood cells and about 45 of the total blood volume are oxygen carrying red blood cells also called erythrocytes o The red color of erythrocytes is caused by the protein hemoglobin which transports oxygen in the blood Understand the structure of hemoglobin and its role regarding O2 and CO2 in the blood Hemoglobin is a protein that transports oxygen in the blood Each hemoglobin cell has 4 iron containing heme groups that can bind four oxygen molecules Oxygenated hemoglobin takes on a bright red color and becomes bluish as it releases oxygen and picks up carbon dioxide at tissues Understand the structural and functional differences between veins arteries venules arterioles and capillaries Heart arteries arterioles capillaries venules veins heart Arteries and arterioles carry blood away from the heart Arterioles control the distribution of blood flow they contract and relax in response to the needs of the tissues and organs they supply The walls of arteries are thicker and more elastic than those of the veins Capillary walls are a single cell thick and allow exchange of nutrients and wastes Arterioles conduct blood into elaborate networks of tiny capillaries microscopically thin vessels Capillaries allow individual body cells to exchange
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