Cardiovascular System PDF

CARDIOVASCULAR SYSTEM A.Blood B.Heart C.Blood Circulation and Cardiac Conduction System D.Blood Vessels ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System major function of the cardiova...

CARDIOVASCULAR SYSTEM A.Blood B.Heart C.Blood Circulation and Cardiac Conduction System D.Blood Vessels ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System major function of the cardiovascular system = transportation  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System BLOOD v liquid connective tissue Ø cells surrounded by a liquid extracellular matrix (blood plasma) v transports: Ø oxygen and nutrients from the lungs and gastrointestinal tract Ø carbon dioxide and other wastes from body cells to lungs, kidneys, and skin for excretion  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System BLOOD v helps maintain homeostasis of all body fluids Ø blood helps regulate pH (through the use of buffer) Ø heat- absorbing and coolant properties of the water in blood plasma helps adjust body temperature  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System BLOOD v clotting= protects against its excessive loss after an injury v white blood cells and blood proteins (e.g. antibodies)= protect against disease  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System BLOOD v physical characteristics: Ø denser and more viscous (thicker) than water Ø temperature= 38ºC Ø pH= 7.35 to 7.45 (slightly alkaline) Ø color with oxygen content: ü saturated with oxygen= bright red ü unsaturated with oxygen= dark red Ø 8% of the total body mass Ø blood volume ü 5 to 6 liters (average- sized adult male) ü 4 to 5 liters (average-sized adult female)  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System v components: 1. blood plasma 2. formed elements  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System 2. formed elements  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System 2. formed elements a. Red blood cells (RBCs) or erythrocytes transport oxygen from the lungs to body cells deliver carbon dioxide from body cells to the lungs diameter= 7- 8 µm no nucleus= all internal space is available for oxygen transport no mitochondria= generate ATP anaerobically (without oxygen biconcave disc= much greater surface area for gas diffusion each contains about 280 million hemoglobin molecules ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System 2. formed elements a. Red blood cells (RBCs) or erythrocytes each contains about 280 million hemoglobin molecules § hemoglobin= where O2 and CO2 bind normal level: 100mL blood= contains 12–18g hemoglobin Iron ion (Fe2+) can combine reversibly with one O2 molecule. Each hemoglobin molecule binds four O2 molecules.  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Hemoglobin also transports about 23% of the total carbon dioxide. The remaining carbon dioxide is dissolved in plasma or carried as bicarbonate ions.  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Ø hematocrit= % total blood volume occupied by RBCs ü normal: adult females= 38–46%; adult males= 40–54% * testosterone stimulates synthesis of erythropoietin (EPO), the hormone that stimulates production of RBCs * excessive loss of blood during menstruation ü significant drop in hematocrit= anemia ü abnormally high hematocrit (65% or higher)= polycythemia raises the viscosity of blood=> difficult for the heart to pump contributes to high blood pressure and increased risk of stroke caused by: § abnormal increases in RBC production, tissue hypoxia, dehydration, and blood doping or the use of EPO by athletes  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Mechanism for regulating the rate of RBC production  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System 2. formed elements b. White blood cells (WBCs) or leukocytes ü helps defend the body against bacteria, viruses, parasites, and tumor cells ü have nuclei and other organelles ü do not contain hemoglobin ü less numerous than red blood cells (5,000-10,000 cells per mL of blood  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System b. White blood cells (WBCs) or leukocytes ü types: Neutrophils= most numerous WBCs § respond most quickly to bacteria and fungi Eosinophils= have a blue-red nucleus § number increases rapidly during infections by parasitic worms Basophils= rarest of the WBCs § contains histamine (chemical that makes blood vessels leaky and attracts other WBCs to the inflamed site)  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System b. White blood cells (WBCs) or leukocytes ü types: Lymphocytes § have a large, dark purple nucleus § reside in lymphatic tissues, such as the tonsils Monocytes § largest of the WBCs § U- or kidney-shaped nucleus § change into macrophages (important in fighting chronic infections) ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System 2. formed elements b. White blood cells (WBCs) or leukocytes ü diapedesis/ emigration= when WBCs slip into and out of the blood vessels circulatory system is their means of transportation to areas of the body ü chemotaxis= WBCs can locate areas of tissue damage and infection in the body ü amoeboid motion= formation of pseudopodia  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Ø leukocytosis= increase in WBC ü generally indicates that a bacterial or viral infection Ø leukopenia= abnormally low WBC ü commonly caused by certain drugs, such as corticosteroids and anti- cancer agents Ø leukemia= cancer of bone marrow ü huge numbers of WBCs are turned out rapidly these WBCs are immature and incapable of carrying out their normal protective functions the body becomes easy prey for disease-causing bacteria and viruses because other blood cell lines are crowded out, severe anemia and bleeding problems result  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System 2. formed elements c. Platelets ü not technically cells fragments of multinucleate cells called megakaryocytes enclosed by a piece of the plasma membrane appear as darkly staining, irregularly shaped bodies scattered among the other blood cells  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System 2. formed elements c. Platelets ü irregularly disc-shaped ü 2–4 µm in diameter ü has many vesicles but no nucleus. ü needed for normal blood clotting stops blood loss from broken blood vessels ü normal platelet count= 150,000 and 400,000 per mL of blood ü have a short life span (5 to 9 days) aged/ dead platelets are removed by fixed macrophages in the spleen and liver  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Platelet plug formation A platelet plug can stop blood loss completely if the hole in a blood vessel is small enough.  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Blood Clotting If blood is drawn from the body, it thickens and forms a gel. The gel is called a blood clot. It consists of a network of insoluble protein fibers called fibrin in which the formed elements of blood are trapped.  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Hematopoiesis or Blood Cell Formation ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Blood Groups and Blood Types  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Development of hemolytic disease of the newborn (HDN) Rh Blood Group Rh factor= an antigen occurring on the red blood cells of many humans (around 85 %) and some other primates  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System HEART v blood should reach body cells Ø must be pumped continuously by the heart through the blood vessels ü heart beat= about 100,000 times every day ü heart pumps more than about 14,000 liters of blood in a day v roughly same size (but not same shape) as your closed fist v average mass Ø adult females= 250 g Ø adult males= 300 g  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System HEART v rests on the diaphragm, near the midline of the thoracic cavity  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System v pericardium= surrounds the heart Ø confines the heart to its position in the mediastinum Ø allows freedom of movement for contraction 2 main parts or pericardium: (1) fibrous - tough, inelastic, dense irregular connective tissue - prevents overstretching of the heart, provides protection, and anchors the heart in the mediastinum  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System 2 main parts or pericardium: (2) Serous - thinner, more delicate membrane - made up of visceral and parietal layer - pericardial cavity= space between the 2 layers pericardial fluid - thin film of lubricating serous fluid ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System PERICARDITIS - inflammation of the pericardium - usually linked to a viral infection - may lead to cardiac tamponade Ø life-threatening condition because the fluid compresses the heart  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System v Layers of the heart wall Ø epicardium ü external layer ü contains blood vessels, lymphatics, and vessels that supply the myocardium Ø myocardium ü middle layer ü composed of cardiac muscle tissue responsible for the pumping action of the heart Ø endocardium ü inner layer ü provides a smooth lining for the chambers of the heart ü covers the valves of the heart ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Chambers of the Heart v right atrium Ø receives blood from: ü superior vena cava ü inferior vena cava ü coronary sinus v right ventricle Ø sends blood to lungs through the pulmonary artery  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Chambers of the Heart v left atrium Ø receives blood from the lungs through the pulmonary vein v left ventricle Ø sends blood to the aorta Ø branches of the arch of the aorta and descending aorta carry blood throughout the body  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Heart Valves Ø open and close in response to pressure changes as the heart contracts and relaxes Ø helps ensure the one- way flow of blood by opening to let blood through and then closing to prevent its backflow ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Coronary Arteries and Veins The left and right coronary arteries deliver blood to the heart; the coronary veins drain blood from the heart into the coronary sinus. ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System BLOOD VESSELS v structures for the flow of blood to and from the heart v play an important role in adjusting the velocity and volume of blood flow v William Harvey Ø proved that blood move in an enclosed system (17th century)  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Structure of the Blood Vessels  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Arteries v carry blood away from the heart v classified as: Ø (1) elastic arteries ü recoil when stretched, which prevents blood pressure from falling rapidly Ø (2) muscular arteries ü regulate blood flow to different regions of the body Ø (3) arterioles ü smallest arteries  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Major Arteries ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Arteries v aorta Ø where arteries are derived from Ø usually divided into : (1) ascending aorta (2) aortic arch (3) descending aorta  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Veins v have very thin walls relative to their total diameter v deoxygenated blood from the body is returned to the right atrium through three major veins: Ø coronary sinus Ø superior vena cava Ø inferior vena cava v many veins, especially those in the limbs, contain valve  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Major Veins  ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System Capillaries v smallest of blood vessels v have diameters of 5–10 µm v form the U-turns that connect the arterial outflow to the venous return ANATOMY and PHYSIOLOGY. Chapter 3G– Circulatory System