Circulatory System Topic 16 PDF

Circulation Chapter 34 Mader: Biology 8th Ed.  Outline Transport in Vertebrates Transport in Humans Heartbeat Vascular Pathways Blood Pressure Cardiovascular Disorders Blood Components Blood Clotting Mader: Biology 8...

Circulation Chapter 34 Mader: Biology 8th Ed.  Outline Transport in Vertebrates Transport in Humans Heartbeat Vascular Pathways Blood Pressure Cardiovascular Disorders Blood Components Blood Clotting Mader: Biology 8th Ed.  Transport in Vertebrates All vertebrates have a closed, cardiovascular system. – Atria receive blood and ventricles pump blood out through blood vesicles. Arteries - Carry blood away from heart. – Arterioles Capillaries - Exchange materials with tissue fluid. Veins - Return blood to heart. – Venules Mader: Biology 8th Ed. Closed Circulatory System Mader: Biology 8th Ed. Mader: Biology 8th Ed.  Transport in Humans Human Heart – Fist-sized, cone-shaped, muscular organ. Myocardium composed largely of cardiac tissue. – Lies within sac (pericardium). Mader: Biology 8th Ed. External Heart Anatomy Mader: Biology 8th Ed.  Transport in Humans Septum separates halves. – Four chambers Two upper, thin atria. Two lower, thick ventricles. – Atrioventricular valves » Tricuspid » Bicuspid – Semilunar valves » Pulmonary » Aortic Mader: Biology 8th Ed. Internal Heart Anatomy Mader: Biology 8th Ed.  Transport in Humans Blood must go through lungs to pass from the right side to the left side of the heart. – Right side of heart pumps blood to the pulmonary circuit. – Left side of the heart pumps blood to the systemic circuit. Oxygen-poor blood never mixes with oxygen- rich blood. Mader: Biology 8th Ed.  Heartbeat Systole - Contraction of heart chambers. Diastole - Relaxation of heart chambers. – Pulse - Wave effect that passes down the walls of arterial blood vessels when aorta expands and then recoils following ventricular systole. Mader: Biology 8th Ed. Conduction System of the Heart Rhythmic contraction Sinoatrial node (SA) keeps the heartbeat regular. Atrioventricular node (AV) signals ventricles to contract. Purkinje Fibers  Heartbeat Electrocardiogram (ECG) is a recording of the electrical changes that occur in myocardium during a cardiac cycle. – When SA node triggers an impulse, the atrial fibers produce an electrical charge (P wave). P wave indicates atria are about to contract.  Vascular Pathways Human cardiovascular system includes two major circular pathways: – Pulmonary Circuit Takes oxygen-poor blood to the lungs and returns oxygen-rich blood to the heart. – Systemic Circuit Takes blood throughout the body from the aorta to the vena cava. Mader: Biology 8th Ed. Mader: Biology 8th Ed.  Blood Pressure Systolic Pressure results from blood forced into the arteries during ventricular systole. Diastolic Pressure is the pressure in the arteries during ventricular diastole. Blood pressure normally measured with a sphygmomanometer on the brachial artery. – Systolic/Diastolic Mader: Biology 8th Ed.  Velocity and Blood Pressure The beat of the heart supplies pressure that keeps blood moving in the arteries. Mader: Biology 8th Ed. Skeletal muscle contraction pushes blood in the veins toward the heart. Mader: Biology 8th Ed.  Cardiovascular Disorders Hypertension - High blood pressure. Atherosclerosis - Accumulation of fatty materials in inner linings of arteries. Stroke - Cranial arteriole bursts or is blocked by an embolus. Heart attack - Myocardial infarction. Coronary artery becomes partially blocked. Mader: Biology 8th Ed. Coronary Arteries and Plaque Mader: Biology 8th Ed.  Blood - A Transport Medium Homeostasis Functions – Transports substances to and from capillaries for exchange with tissue fluid. – Guards against pathogen invasion. – Regulates body temperature – Clots preventing blood loss Mader: Biology 8th Ed.  Plasma Plasma contains many types of molecules including nutrients, wastes, salts, and proteins. – Buffer blood. – Maintain osmotic pressure. – Proteins involved in clotting. Mader: Biology 8th Ed.  Red Blood Cells Small, biconcave disks that, at maturity, lack a nucleus and contain hemoglobin. – Hemoglobin contains four globin protein chains, each associated with an iron-containing group. Manufactured continuously in bone marrow of skull, ribs, vertebrae, and ends of long bones.  White Blood Cells Usually larger than red blood cells, contain a nucleus, and lack hemoglobin. Inflammatory Response – Neutrophils enter tissue fluid and phagocytize foreign material. – Lymphocytes help fight infection. T Cells attack infected cells. – Antigens cause body to produce antibodies. Mader: Biology 8th Ed. Blood Clotting Blood clot consists of platelets and red blood cells entangled within fibrin threads. Mader: Biology 8th Ed.