1 / 61

Cardiovascular System

Cardiovascular System. Anatomy and Physiology.

aram
Download Presentation

Cardiovascular System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Cardiovascular System Anatomy and Physiology

  2. Two children were sitting outside a clinic. One of them was crying very loudly. 2nd Child: Why are you crying? 1st Child: I came here for a blood test. 2nd Child: So? Are you afraid? 1st Child: No. For the blood test, they cut my finger. At this, the second one started crying profusely. The first one was astonished. 1st Child: Why are you crying now? 2nd Child: I came for a urine test!

  3. Overview of Blood Circulation • Blood leaves the heart via arteries that branch repeatedly until they become capillaries • Oxygen (O2) and nutrients diffuse across capillary walls and enter tissues • Carbon dioxide (CO2) and wastes move from tissues into the blood • Oxygen-deficient blood leaves the capillaries and flows in veins to the heart • This blood flows to the lungs where it releases CO2 and picks up O2 • The oxygen-rich blood returns to the heart

  4. Composition of Blood • Blood is the body’s only fluid tissue • It is composed of liquid plasma and formed elements • Formed elements include: • Erythrocytes, or red blood cells (RBCs) • Leukocytes, or white blood cells (WBCs) • Platelets (Thrombocytes) • Hematocrit – the percentage of RBCs out of the total blood volume

  5. Composition of Blood Figure 18.1

  6. Physical Characteristics and Volume • Blood is a sticky, opaque fluid with a metallic taste • Color varies from scarlet (oxygen-rich) to dark red (oxygen-poor) • The pH of blood is 7.35–7.45 • Temperature is 38C, slightly higher than “normal” body temperature • Blood accounts for approximately 8% of body weight • Average volume of blood is 5–6 L for males, and 4–5 L for females

  7. Functions of Blood • Blood performs a number of functions dealing with: • Substance distribution • Regulation of blood levels of particular substances • Body protection

  8. Blood Plasma • Blood plasma contains over 100 solutes, including: • Proteins – albumin, globulins, clotting proteins, and others • Nonprotein nitrogenous substances – lactic acid, urea, creatinine • Organic nutrients – glucose, carbohydrates, amino acids • Electrolytes – sodium, potassium, calcium, chloride, bicarbonate • Respiratory gases – oxygen and carbon dioxide

  9. Erythrocytes (RBCs) • Biconcave discs, anucleate, essentially no organelles • Filled with hemoglobin (Hb), a protein that functions in gas transport • Contain the plasma membrane protein spectrin that: • Gives erythrocytes their flexibility • Allows them to change shape as necessary Figure 18.3

  10. Erythrocyte Function • Erythrocytes are dedicated to respiratory gas transport • Hemoglobin reversibly binds with oxygen and most oxygen in the blood is bound to hemoglobin • Hemoglobin is composed of: • The protein globin, made up of two alpha and two beta chains, each bound to a heme group • Each heme group bears an atom of iron, which can bind one to oxygenmolecule • Each hemoglobin molecule can transport four molecules of oxygen

  11. Erythrocyte Function Figure 18.4a, b

  12. Hormonal Control of Erythropoiesis • Erythropoietin (EPO) release by the kidneys is triggered by: • Hypoxia due to decreased RBCs • Decreased oxygen availability • Increased tissue demand for oxygen • Enhanced erythropoiesis increases the: • RBC count in circulating blood • Oxygen carrying ability of the blood increases

  13. Hormonal Control of Erythropoiesis Figure 18.6

  14. Life Cycle of Red Blood Cells Figure 18.7

  15. Leukocytes (WBCs) • Leukocytes, the only blood components that are complete cells: • Are less numerous than RBCs • Make up 1% of the total blood volume • Can leave capillaries via diapedesis • Move through tissue spaces • Leukocytosis – WBC count over 11,000 per cubic millimeter • Normal response to bacterial or viral invasion

  16. Platelets • Platelets are fragments of megakaryocytes with a blue-staining outer region and a purple granular center • The granules contain serotonin, Ca2+, enzymes, ADP, and platelet-derived growth factor (PDGF) • Platelets function in the clotting mechanism by forming a temporary plug that helps seal breaks in blood vessels

  17. White blood cells Platelets Red blood cells

  18. Neutrophil Lymphocyte

  19. Monocyte

  20. Eosinophil Lymphocyte

  21. Neutrophil Basophil Monocyte

  22. 6 3 4 2 5 1

  23. Infection

  24. Sickle cell anemia

  25. Leukemia

  26. Hemostasis • A series of reactions designed for stoppage of bleeding • During hemostasis, three phases occur in rapid sequence • Vascular spasms – immediate vasoconstriction in response to injury • Platelet plug formation • Coagulation (blood clotting)

  27. Blood Typing • When serum containing anti-A or anti-B agglutinins is added to blood, agglutination will occur between the agglutinin and the corresponding agglutinogens • Positive reactions indicate agglutination

  28. Heart Anatomy • Approximately the size of your fist • Location • Superior surface of diaphragm • Left of the midline • Anterior to the vertebral column, posterior to the sternum

  29. Heart Anatomy Figure 19.1

  30. Heart Covering • Pericardial physiology • Protects and anchors heart • Prevents overfilling Figure 19.2

  31. Heart Covering • Pericardial anatomy • Fibrous pericardium • Serous pericardium (separated by pericardial cavity) • Epicardium (visceral layer) Figure 19.2

  32. Heart Wall • Epicardium – visceral layer of the serous pericardium • Myocardium – cardiac muscle layer forming the bulk of the heart • Fibrous skeleton of the heart – crisscrossing, interlacing layer of connective tissue • Endocardium – endothelial layer of the inner myocardial surface

  33. External Heart: Anterior View Figure 19.4b

  34. Atria of the Heart • Atria are the receiving chambers of the heart • Each atrium has a protruding auricle • Pectinate muscles mark atrial walls • Blood enters right atria from superior and inferior venae cavae and coronary sinus • Blood enters left atria from pulmonary veins

  35. Ventricles of the Heart • Ventricles are the discharging chambers of the heart • Papillary muscles and trabeculae carneae muscles mark ventricular walls • Right ventricle pumps blood into the pulmonary trunk • Left ventricle pumps blood into the aorta

  36. Gross Anatomy of Heart: Frontal Section Figure 19.4e

  37. Pathway of Blood through the Heart and Lungs • Right atrium  tricuspid valve  right ventricle • Right ventricle  pulmonary semilunar valve  pulmonary arteries  lungs • Lungs  pulmonary veins  left atrium • Left atrium  bicuspid valve  left ventricle • Left ventricle  aortic semilunar valve  aorta • Aorta  systemic circulation

  38. Pathway of Blood through the Heart and Lungs Figure 19.5

  39. Heart Valves • Heart valves insure unidirectional blood flow through the heart • Atrioventricular (AV) valves lie between the atria and the ventricles • AV valves prevent backflow into the atria when ventricles contract • Chordae tendineae anchor AV valves to papillary muscles

  40. Heart Valves Figure 19.9

  41. Heart Valves • Aortic semilunar valve lies between the left ventricle and the aorta • Pulmonary semilunar valve lies between the right ventricle and pulmonary trunk • Semilunar valves prevent backflow of blood into the ventricles

  42. Heart Valves Figure 19.10

  43. Heart Physiology: Sequence of Excitation • Sinoatrial (SA) node generates impulses about 75 times/minute • Atrioventricular (AV) node delays the impulse approximately 0.1 second • Impulse passes from atria to ventricles via the atrioventricular bundle (bundle of His)

  44. Heart Physiology: Sequence of Excitation • AV bundle splits into two pathways in the interventricular septum (bundle branches) • Bundle branches carry the impulse toward the apex of the heart • Purkinje fibers carry the impulse to the heart apex and ventricular walls

  45. Heart Physiology: Sequence of Excitation Figure 19.14a

  46. Electrocardiography • Electrical activity is recorded by electrocardiogram (ECG) • P wave corresponds to depolarization of atria • QRS complex corresponds to ventricular depolarization • T wave corresponds to ventricular repolarization • Atrial repolarization record is masked by the larger QRS complex

  47. Electrocardiography Figure 19.16

  48. videos • heart beat electricity • http://medmovie.com/mmdatabase/flash/0007a.swf • ecg • http://medmovie.com/mmdatabase/flash/0038a.swf • all animations • http://science.nhmccd.edu/biol/ap2int.htm#cardio • heart valves • http://www.wellesley.edu/Biology/Courses/111/HeartValves.MOV • visible heart video clips • http://www.visibleheart.com/videoclips.html • arrythmeias • http://medmovie.com/mmdatabase/flash/0078a.swf • heart attack • http://medmovie.com/mmdatabase/flash/0072a_B.swf

  49. Cardiac Cycle • Cardiac cycle refers to all events associated with blood flow through the heart • Systole – contraction of heart muscle • Diastole – relaxation of heart muscle

More Related