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 o Heart the pump that keeps the blood circulating o Blood a liquid that serves as a medium of transport o Blood vessels a system of tubes that conduct the blood throughout the body Understand the functions of the human circulatory system o Transport O2 from the lungs or gills to the tissues and transport CO2 from the tissues to o Distribute nutrients from the digestive system to all body cells o Transport of waste products and toxics substances to the liver where many of them are detoxified and to the kidneys for excretion o Distribution of hormones from the glands and organs that produce them to the tissues the lungs or gills on which they act o Regulation of body temperature by adjustments in blood flow o Wound healing and blood clotting to prevent blood loss o Protection against disease by circulating white blood cells and antibodies Understand how the human heart differs from fish amphibian and reptile hearts o The human heart has 3 chambers which consist of two atria and one ventricle o Fish only had 2 chambers with a single atrium that empties into a single ventricle Understand the circulation terminology o A rtery vessel that carries blood AWAY from the heart o Vein vessel that carries blood TO the heart o Pulmonary having to do with the lungs o Systemic having to do with everywhere else in the body o V ena cava largest vein in the human body o A orta largest artery in the human body Be able to trace the flow of blood through the mammalian heart including all valves swinging doors involved o When valves contract blood must be prevented from flowing back into the atria Blood entering the pulmonary artery and aorta must also be prevented from flowing back into the ventricles as the heart relaxes o The directionality of blood flow is maintained by one way valves o Pressure in one direction opens them but reverse pressure forces them closed o Artioventricular valves AV allow blood to flow from the atria into the ventricles but o Semilunar valves allow blood to enter the pulmonary artery and the aorta when the ventricles contract but prevent blood from returning as the ventricles relax Understand the difference between systolic and diastolic pressure and what causes each o Systolic pressure the higher of the 2 measured during ventricular contraction o Diastolic pressure minimum pressure in the arteries as the heart rests between not the reverse contractions o Hypertension is caused by the constriction of small arteries which causes resistance to blood flow and strain on the heart Be able to trace the flow of the electrical signal throughout the heart and all of the structures involved 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 SA node located in the upper wall of the right o Electrical signals from the SA node pass freely into the connecting cardiac muscle cells atrium and then throughout the atria o 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 Understand the purpose of the AV nodal delay Understand the major components of both the plasma portion and cellular portion of blood and their functions o Blood has two major components Plasma 55 of total blood volume Primarily water in which proteins salts nutrients and wastes are dissolved Proteins are the most abundant dissolved molecules by weight and include o Albumin maintains the blood s osmotic strength o Globulins antibodies that play an important part in immune response o Fibrinogen blood clotting Cell based portion which is 40 45 of total blood volume and consists of Red blood cells nucleus o Mature red blood cells are not actual cells because they lack a o Carry oxygen from the lungs to the tissues Most are oxygen carrying red blood cells called erythrocytes Red color caused by hemoglobin which transports oxygen to the blood o Lifespan of about 4 months o Iron from the erythrocytes is returned to the bone marrow where it is recycled into new red blood cells White blood cells o Only complete functional cells o Break down the old red blood cells o Defend the body against disease o 5 types also called leukocytes Neutrophils Eosinophils Basophils Lymphocytes Monocytes enter tissues and transform into macrophages that engulf bacteria and cellular debris Platelets o Small fragments of cells o Aid in blood clotting o Platelets are pieces of megakaryocytes that reside in bone marrow o Blood clotting is a complex process that plugs damaged blood vessels and protects animals from excessive blood loss All three originate from stem cells o Unspecialized cells that can divide to produce offspring capable of maturing into one or more types of specialized cells Understand the structure of hemoglobin and its role regarding O2 and CO2 in the blood o Each one has a 4 iron containing heme groups that can bind four oxygen molecules Oxygenated hemoglobin takes on a bright red color Hemoglobin becomes bluish as it releases 02 and picks up CO2 at tissues Understand the structural and functional differences between veins arteries venules arterioles and capillaries o Arteries and arterioles carry blood away from the heart The walls of arteries are thicker and more elastic than those of veins With each heartbeat the arteries expand slightly like thick walled balloons Arteries branch into smaller diameter vessels called arterioles o Capillaries o 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 nutrients and wastes with the blood by diffusion They are so numerous that most of the body s cells are no more than 100 micrometers from a capillary which is
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