Name: Date: Class: Unit 5 Outline: Blood and the Cardiovascular System

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1 Name: Date: Class: Unit 5 Outline: Blood and the Cardiovascular System Blood and RBCs Blood The only Classified as a Non-living matrix = Blood Composition tissue in the human body tissue cells = formed elements (55%) Cells (45%) proteins- help stem blood loss when a blood vessel is injured - help protect the body from antigens Formed Elements = red blood cells = white blood cells = cell fragments Physical Characteristics of Blood Color range Oxygen-rich blood is Oxygen- ph must remain between Blood temperature is slightly than body temperature Blood Plasma Approximately Dissolved substances Salts (metal ions) Respiratory Plasma Proteins red blood is dull red water products - regulates osmotic pressure Erythrocytes (Red Blood Cells) 4-6 million cells/mm 3 Main function- carry Anatomy of circulating erythrocytes Essentially bags of Contain very few Outnumber white blood cells Hemoglobin disks (no nucleus) -containing protein Binds strongly, but reversibly, to O 2 Each hemoglobin molecule has O 2 binding sites Each erythrocyte has hemoglobin molecules Hematopoiesis Blood cell Occurs in Unit 5 Outline: Blood and the Cardiovascular System 9

2 All blood cells are derived from a common cell (hemocytoblast) Hemocytoblast differentiation other formed elements Fate of Erythrocytes stem cell produces stem cell produces Unable to divide, grow, or synthesize proteins Wear out in When worn out, are eliminated by phagocytes in the or Lost cells are replaced by division of hemocytoblasts Control of Erythrocyte Production Rate is controlled by a hormone days ( ) produce most erythropoietin as a response to reduced oxygen levels in the blood Homeostasis is maintained by feedback from blood oxygen levels 11,000 leukocytes/ml Generally indicates an Abnormally leukocyte level Commonly caused by certain Types of Leukocytes Granules in their cytoplasm can be Include neutrophils, eosinophils, and basophils No visible cytoplasmic Include lymphocytes and monocytes Leukocytes and Platelets Leukocytes (White Blood Cells) Crucial in body s defense against cells, with a nucleus and organelles Able to move into and out of blood (diapedesis) Can move by Can respond to released by damaged tissues Leukocyte Levels in the Blood Normal levels are between cells per millimeter Abnormal leukocyte levels motion Granulocytes Multilobed nucleus with Act as sites of infection Found in response to and parasitic worms Have granules Initiate Agranulocytes granules at active brick-red cytoplasmic granules -containing fills most of the cell Unit 5 Outline: Blood and the Cardiovascular System 10

3 Important role in the response Function as of the white blood cells Important in fighting infection Platelets Derived from ruptured multinucleate cells ( ) Needed for the Normal platelet count = Hemostasis Hemostasis process /mm3 of blood flow Result of a break in a blood vessel Hemostasis involves Platelet Plug Formation phases formation spasms fibers are exposed by a break in a blood vessel Platelets become to fibers Anchored platelets release to attract more platelets Platelets pile up to form a platelet plug Vascular Spasms Anchored platelets release Serotonin causes blood vessel muscles to Spasms decreasing blood loss Coagulation and cling the blood vessel, Injured tissues release PF3 (a phospholipid) interacts with thromboplastin, blood protein clotting factors, and calcium ions to trigger a clotting cascade Prothrombin activator converts prothrombin to thrombin (an enzyme) Thrombin joins proteins into hair-like fibrin Fibrin forms a basis for a clot) (the Blood Clotting Blood usually clots within Clot remains as regenerates Clot is broken down after tissue repair Undesirable Clotting A clot in an vessel Can be deadly in areas like the Thrombus that breaks away and minutes blood in the bloodstream Can later clog vessels in critical areas (brain or Bleeding Disorders deficiency Even normal movements can cause bleeding from small blood vessels that require platelets for clotting bleeding disorder Normal factors are missing Blood Types Blood Groups and Transfusions Large loss of blood has serious consequences Loss of Loss of over 30 percent causes (can be fatal) percent causes weakness are the only way to replace blood quickly Transfused blood must be of the same ) Unit 5 Outline: Blood and the Cardiovascular System 11

4 Human Blood Groups Blood contains genetically determined A foreign protein ( attacked by the immune system ) may be Blood is typed by using that will cause blood with certain proteins to clump (agglutination) There are over antigens common red blood cell The most vigorous transfusion reactions are caused by and blood group antigens ABO Blood Groups Based on the presence or absence of two antigens Presence of both called type AB Presence of A antigen is called Presence of B antigen is called Absence of both antigens is called Rh Blood Groups Named because of the presence or absence of one of eight (agglutinogen D) Most Americans are Problems can occur in mixing Rh + blood into a body with Rh - blood Blood Typing Blood samples are mixed with and anti-b serum or no coagulation leads to determining blood type Typing for ABO and Rh factors is done in the same manner - testing for agglutination of donor RBCs by the recipient s serum, and vice versa is Rh Dangers During Pregnancy Danger when mother is is Rh +, and the child inherits the The mismatch of an an the unborn child proceeds without problems and the father factor mother carrying baby can cause problems for pregnancy usually Immune system is after the first pregnancy In a 2 nd pregnancy, mother s immune system produces to attack the Rh + blood (hemolytic disease of the newborn) prevent sensitization Developmental Aspects of Blood Sites of blood cell formation Fetal and are early sites of blood cell formation - given to Bone marrow takes over hematopoiesis by the Fetal hemoglobin differs from hemoglobin produced after birth The Heart: Coverings, Layers, and Valves The Cardiovascular System A closed system of the blood vessels Heart Blood vessels allow blood to to all parts of the body month and blood Unit 5 Outline: Blood and the Cardiovascular System 12

5 Function- deliver oxygen and and to remove and other waste products The Heart Pointed About the size of your between the lungs directed toward left hip (right and left) chambers (right and left) chambers Heart Coverings - a double serous membrane Next to heart Outside layer pericardium pericardium fluid fills the space between the layers of pericardium The Heart Wall Three layers layer This layer is the parietal pericardium tissue layer layer Mostly muscle layer Heart Chambers Right and left side act as pumps Four chambers Heart Valves Allow blood to flow in only one direction valves atria and ventricles valves- between valve (left) valve (right) between ventricle and artery valves semilunar valve semilunar valve Valves open as blood is pumped through Held in place by ( heart strings ) Unit 5 Outline: Blood and the Cardiovascular System 13

6 Close to prevent backflow Atrioventricular Bundle node fibers The Heart: Associated Vessels and Conduction Associated Leaves left ventricle to body Vessels ( ) arteries Leave right ventricle to Enters Pulmonary Enter left atrium (four) Circulation Blood in the heart chambers does not nourish the myocardium The heart has its own nourishing Blood empties into the right atrium via the coronary The Heart Conduction System system arteries veins conduction system (nodal system) Heart muscle cells contract, nerve impulses, in a regular, continuous way Special tissue sets the pace (initiates contraction) Pacemaker node The Cardiac Cycle Atria contract Atria relax, then ventricles contract = contraction = relaxation - events of one complete heart beat Mid-to-late diastole- blood flows into ventricles Ventricular - blood pressure builds before ventricle contracts, pushing out blood Early - atria finish re-filling, ventricular pressure is low Cardiac Output Cardiac output (CO) Amount of blood pumped by each side of the heart in volume [SV]) minute = (heart rate [HR]) x (stroke Volume of blood pumped by each Regulation of Heart Rate in one contraction Unit 5 Outline: Blood and the Cardiovascular System 14

7 Stroke volume usually remains constant law of the heart- the more that the cardiac muscle is stretched, the stronger the contraction Changing most common way to change cardiac output Increased heart rate is the nervous system blood pressure Hormones Decrease Decreased heart rate system Decreased Blood Vessels blood volume nervous blood pressure or blood volume Blood Vessels: The Vascular System Taking blood to the tissues and back return Blood Vessels: Anatomy layers (tunics) Tunic intima Tunic media muscle Controlled by sympathetic nervous system Tunic externa Mostly fibrous tissue Blood Vessel Differences Walls of arteries are the of veins are larger Skeletal muscle milks blood in veins toward the heart Walls of capillaries are only cell layer thick to allow for exchanges between blood and tissue Movement of Blood Through Vessels Most arterial blood is pumped by the Veins use the of muscles to help move blood action Unit 5 Outline: Blood and the Cardiovascular System 15

8 Fenestrations of some Fenestrations = Capillary Beds Capillary beds consist of Vascular connects an arteriole to a venule types of vessels - directly capillaries- exchange vessels O 2 and cross to cells CO 2 and metabolic waste products leave the cells Pulse - pressure wave of blood Monitored at where pulse is easily palpated Capillary Exchange: Mechanisms Direct across plasma membrane Endocytosis or Some capillaries have gaps (intercellular ) Plasma membrane not joined by tight junctions Blood Pressure Measurements are made on the pressure in Pressure of ventricular contraction ventricles relax away from the heart arteries - pressure at the peak - pressure when as the distance Unit 5 Outline: Blood and the Cardiovascular System 16

9 Blood Pressure: Effects of Factors Neural factors nervous system adjustments (sympathetic division) factors Regulation by altering blood volume Heat has a effect Cold has a effect - hormonal control Various substances can cause increases or decreases Variations in Blood Pressure Human normal range is variable Normal mm Hg systolic mm Hg diastolic Hypotension systolic (below 110 mm HG) Often associated with systolic (above 140 mm HG) Can be dangerous if it is Cardiovascular Homeostatic Imbalances Crushing chest pain caused by oxygen deprivation of the Veins Caused by weakened venous Usually occurs in the Caused by defective Common in healthy hearts with Lack of to the heart Cardiovascular System Development Simple tube heart develops in the embryo and pumps by the week The heart becomes a four-chambered organ by the end of weeks Few structural changes occur after the seventh week Unit 5 Outline: Blood and the Cardiovascular System 17