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cardiovascular and hematologic systems
study notes
200 points 25 mc, 10 short answer questions, 3 essay questions
- Blood all functions of blood p. 662 a. The blood has 3 functions i. Transportation 1. Transports oxygen from lungs to cells of the body and carbon dioxide form the body to the lungs. It also carries nutrients, gases, waste and hormones. ii. Regulation:
- Circulating blood helps maintain homeostasis of all body fluids. a. Blood’s ph buffer system b. Body temperature regulation c. Blood osmotic pressure influences the water content of cells. iii. Protection:
- Blood can clot
- White blood cells protects against disease by phagocytosis
- Other proteins help protect the body from disease.
- Know mesenchymal to blood cells, know derevatives of blood cells 665 a. Hematopoiesis b. Leukopoeisis c. Know steps d. Red bone marrow is a highly vascularized connective tissue located in the microscopic spaces between trabeculae of spongy bone tissue. It is present chiefly in bones of the axial skeleton, pectoral and pelvic girdles, and the proximal epiphyses of the humerus and femur. About 0.05–0.1% of red bone marrow cells are called pluripotent stem cells or hemocytoblasts and are derived from mesenchyme (tissue from which almost all connective tissues develop). e. pluripotent stem cells in red bone marrow produce two further types of stem cells, which have the capacity to develop into several types of cells. These stem cells are called myeloid stem cells and lymphoid stem cells. Myeloid stem cells begin their development in red bone marrow and give rise to red blood cells, platelets, monocytes, neutrophils, eosinophils, basophils, and mast cells. f. The process of producing blood cells is hemopoiesis (hematopoiesis). Pluripotent
stem cells differentiate into each of the different types of blood cells. g. During hematopoiesis, some myeloid cells become progenitor cells and other become precursor cell.
vii. Each RBC contains about 280 million hemoglobin molecules. viii. ix. Red blood cells live for only about 120 days. Dead cells are removed from the circulation by the spleen and liver. x. Breakdown products from the cells are recycled and reused. xi. Production of RBC
- Erythropoiesis , the production of RBCs, starts in the red bone marrow with a precursor cell called a proerythroblast
- The proerythroblast divides several times, producing cells that begin to synthesize hemoglobin. Ultimately, a cell near the end of the development sequence ejects its nucleus and becomes a reticulocyte
- Reticulocytes develop into mature red blood cells within 1 to 2 days after their release from red bone marrow. xii. Hemostasis of RBC count
xiii. c. White blood cells i. White blood cells (leukocytes) contain a nucleus and organelles, but no hemoglobin. ii. Leukocytes are classified as either granular (containing vesicles that appear when the cells are stained) or agranular (containing no granules). iii. Granular leukocytes: neutrophils, eosinophils, basophils
- Neutrophil: The nucleus has two to five lobes, connected by very thin strands of nuclear material. As the cells age, the number of nuclear lobes increases. a. Phagocytosis and produce lysozyme b. Most numerous of WBC
v. vi. d. White blood cells and all other nucleated cells in the body have proteins, called major histocompatibility (MHC) antigens , protruding from their plasma membrane into the extracellular fluid. These “cell identity markers” are unique for each person i. e. Platelets i. Are not cells, they are fragments of megakaryocytes ii. Platelets are used to clot the blood. iii. Under the influence of the hormone thrombopoietin , hemopoietic stem cells differentiate into platelets. iv. Megakaryocytes in red bone marrow splinter into 2000– 3000 fragments to create the platelets that contain many vesicles but no nucleus. v. Platelets survive for only 5 to 9 days. vi. Normal value is 250,000 /mm
f. g.
iv. Components of hemostasis b. Couagulation i. Anti and couagulants ii. Agglutinaition c. Hemostasis i. Hemostasis means to stop bleeding. Is sequence of responses that stops bleeding. ii. The process involves 3 mechanism to reduce blood loss:
- Vascular spasm a. When arteries or arterioles are damaged, the circularly arranged smooth muscle in their walls contracts immediately
- Platelet plug formation a. Platelets contain many cloting factors: i. ADP, ATP, CA2+, and serptonin ii. Enzymes that produce thromboxane A2, and prostaglandin. iii. within platelets is platelet- derived growth factor (PDGF) , a hormone that can cause proliferation of vascular endothelial cells, vascular smooth muscle fibers, and fibroblasts to help repair damaged blood vessel walls.
- Blood clotting (coagulation) a. Normally, blood remains in its liquid form as long as it stays within its vessels. If it is drawn from the body, however, it thickens and forms a gel. b. The gel is a blood clot. c. The process of gel formation, called clotting or coagulation is a series of chemical reactions that culminates in formation of fibrin threads. iii. Blood clotting involves several clotting (coagulation) factors identified by Roman numerals and divided into three stages. iv. The three stages are the extrinsic pathway , intrinsic pathway and common pathway. v.
vi. vii. Once the clot forms, it consolidates (tightens) to pull the edges of the damaged vessel together. viii. Vitamin K is needed for normal clot formation although it is not directly involved. It is used in the synthesis of 4 clotting factors. ix. Small, unwanted clots are usually dissolved by plasmin (fibrinolysin). x. The extrinsic pathway
- The extrinsic pathway of blood clotting has fewer steps than the intrinsic pathway and occurs rapidly—within a matter of seconds if trauma is severe. It is so named because a tissue protein called tissue factor (TF) , also known as thromboplastin , leaks into the blood from cells outside (extrinsic to) blood vessels and initiates the formation of prothrombinase. xi. The intrinsic pathway
- The intrinsic pathway of blood clotting is more complex than the extrinsic pathway, and it occurs more slowly, usually requiring several minutes. The intrinsic pathway is so named because its activators are either in direct contact with blood or contained within (intrinsic to) the blood; outside tissue damage is not needed.
- If endothelial cells become roughened or damaged, blood can come in contact with collagen fibers in the connective tissue around the endothelium of the blood vessel.
- Contact with collagen fibers (or with the glass sides of a blood collection tube) activates clotting factor XII, which begins a sequence of reactions that eventually activates clotting factor X. Platelet phospholipids and Ca2+^ can also participate in the activation of factor X. Once factor X is activated, it combines with factor V to form the active enzyme prothrombinase (just as occurs in the extrinsic pathway), completing the intrinsic pathway. xii. The common pathway
g. h. In order to determine a person’s blood type, typing and cross-matching are performed. i. A drop of blood is mixed with an antiserum that will agglutinate (clumping) blood cells that possess agglutinogens that react with it. j. Hemolytic disease of newborn i. At birth, small amounts of fetal blood leak into the maternal circulation. If the baby is Rh+^ and the mother is Rh–, she will develop antibodies to the Rh factor. ii. During her next pregnancy with an Rh+^ baby, when she transfers antibodies to the fetus (a normal occurrence), transferred anti Rh antibodies will attack some of the fetus’ red blood cells causing agglutination and hemolysis. iii.
- Blood related conditions and disorders 683 a. Hemolytic Disease of the Newborn i. if a small amount of Rh+^ blood leaks from the fetus through the placenta into the bloodstream of an Rh−^ mother, the mother will start to make anti-Rh antibodies. Because the greatest possibility of fetal blood leakage into the maternal circulation occurs at delivery, the firstborn baby usually is not affected. If the mother becomes pregnant again, however, her anti-Rh antibodies can cross the placenta and enter the bloodstream of the fetus. If the fetus is Rh−, there is no problem, because Rh−^ blood does not have the Rh antigen. If the fetus is Rh+, however, agglutination and hemolysis brought on by fetal– maternal incompatibility may occur in the fetal blood. b. Anemia i. a condition in which the oxygen-carrying capacity of blood is reduced. All of the many types of anemia are characterized by reduced numbers of RBCs or a decreased amount of hemoglobin in the blood.
ii. Iron-deficiency anemia
- involves cells derived from lymphoid stem cells iv. Myelogenous leukemia
- involves cells derived from myeloid stem cells
- Anatomy of heart 689 a. Location of the Heart i. The heart rest on the diaphragm, near the midline of the thoracic cavity within the mediastimunum. ii. About 2/3 of the heart’s mass lies to the left of the body’s midline iii. The apex of the heart is formed by the tip of the left ventricle and rests on the diaphragm. (anteriorly and inferiorly towards left hip) iv. The base of the heart is opposite to the apex. It is formed by the atria. v.
- Chambers a. Know the Chambers of the Heart (A.V valves, tricuspid and mitral, pulmonary and aortic semilunar valves. ) b. The chambers of the heart include two upper atria and two lower ventricle c. On the anterior surface of each atrium is a wrinkled pouchlike structure called an auricle i. It allows the atria to expand and hold more blood d. The heart also has sulci which mark the external boundary of the chambers of the heart and contain fat and coronary blood vessels. i. The deep coronary sulcus encircles most of the heart and marks the external boundary between the superior atria and inferior ventricles. ii. The anterior interventricular sulcus is on the anterior surface of the heart that marks the external boundary between the right and left ventricles on the anterior aspect of the heart. This sulcus
continues around to the posterior surface of the heart as the posterior interventricular sulcus , which marks the external boundary
14.Valves 696 of Blood a. Heart Valves and Circulation i. The valves of the heart open and close in response to pressure changes as the heart contracts and relaxes
- Right and left atrioventricular valves a. Prevent back flow from the ventricles into the atria
- Right and left semilunar valves a. Prevent back flow from the arteries into the ventricles b. Operation of AV Valve i. When an AV valve is open, the rounded ends of the cusps project into the ventricle. When the ventricles are relaxed, the papillary muscles are relaxed, the chordae tendineae are slack, and blood moves from a higher pressure in the atria to a lower pressure in the ventricles through open AV valves. ii. When the ventricles contract, the pressure of the blood drives the cusps upward until their edges meet and close the opening. iii. At the same time, the papillary muscles contract, which pulls on and tightens the chordae tendineae. This prevents the valve cusps from everting (opening into the atria) in response to the high ventricular pressure. If the AV valves or chordae tendineae are damaged, blood may regurgitate (flow back) into the atria when the ventricles contract. c. Operation of the semilunar valve i. When one set of valves is open, the other set is closed ii. The aortic and pulmonary valves are known as the semilunar (SL) valves because they are made up of three crescent moon–shaped cusps iii. Each cusp attaches to the arterial wall by its convex outer margin. The SL valves allow ejection of blood from the heart into arteries but prevent backflow of blood into the ventricles. iv. The semilunar valves open when pressure in the ventricles exceeds the pressure in the arteries, permitting ejection of blood from the ventricles into the pulmonary trunk and aorta v. As the ventricles relax, blood starts to flow back toward the heart. This backflowing blood fills the valve cusps, which causes the free edges of the semilunar valves to contact each other tightly and close the opening between the ventricle and artery
15.Major blood vessel attached 16. arteri es
- Coronary a. two coronary arteries, the left and right coronary arteries, branch from the ascending aorta and supply oxygenated blood to the myocardium ventricles. b. The left coronary artery passes inferior to the left auricle and divides into the anterior interventricular and circumflex branches. c. anterior interventricular branch or left anterior descending (LAD) artery is in the anterior interventricular sulcus and supplies oxygenated blood to the walls of both d. The circumflex branch lies in the coronary sulcus and distributes oxygenated blood to the walls of the left ventricle and left atrium. e. The right coronary artery supplies small branches to the right atrium. It continues inferior to the right auricle and ultimately divides into the posterior interventricular and marginal branches. f. The posterior interventricular branch follows the posterior interventricular sulcus and supplies the walls of the two ventricles with oxygenated blood. g. The marginal branch beyond the coronary sulcus runs along the right margin of the heart and transports oxygenated blood to the wall of the right ventricle.
- Coronary veins a. Most of the deoxygenated blood from the myocardium drains into a large vascular sinus in the coronary sulcus on the posterior surface of the heart, called the coronary sinus b. The principal tributaries carrying blood into the coronary sinus are the following: i. Great cardiac vein in the anterior interventricular sulcus, which drains the areas of the heart supplied by the left coronary artery ii. Middle cardiac vein in the posterior interventricular sulcus, which drains the areas supplied by the posterior interventricular branch of the right coronary artery iii. Small cardiac vein in the coronary sulcus, which drains the right atrium and right ventricle iv. Anterior cardiac veins , which drain the right ventricle and open directly into the right atrium 17.Layers of the heart a. Pericardium i. Membrane that surrounds and protect the heart ii. The heart is enclosed and held in place by the pericardium iii.
