1 / 48

Chapter 15 The Circulation of the Blood

Chapter 15 The Circulation of the Blood. Structure and Function of Blood Vessel Circulation and Related Disorders. Describe the structure and function of each major type of blood vessel: artery, vein, and capillary. List the major disorders of blood vessels and explain how they develop.

genesis
Download Presentation

Chapter 15 The Circulation of the Blood

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. Chapter 15 The Circulation of the Blood

  2. Structure and Function of Blood Vessel Circulation and Related Disorders Describe the structure and function of each major type of blood vessel: artery, vein, and capillary. List the major disorders of blood vessels and explain how they develop. Trace the path of blood through the systemic, pulmonary, portal, and fetal circulations. Lesson 15.1

  3. Blood Vessels Types Arteries—carry blood away from the heart and toward capillaries Veins—carry blood toward the heart and away from capillaries Capillaries—carry blood from the arterioles to the venules

  4. Structure of Blood Vessels • Arteries • Tunica intima—inner layer of endothelial cells • Tunica media—smooth muscle, thick in arteries; some elastic tissue; important in blood pressure regulation • Tunica externa—outer layer of fibrous connective elastic tissue • Capillaries—microscopic vessels • Only one layer—the tunica intima

  5. Structure of Veins • Tunica intima—inner layer; valves prevent retrograde movement of blood • Tunica media—smooth muscle; thin in veins • Tunica externa—heavy layer of fibrous connective tissue in many veins

  6. Artery and Vein

  7. Blood Vessels • Functions • Arteries—distribute nutrients, gases, etc., carried in the blood by way of high pressure; assist in maintaining the arterial blood pressure; serve as blood reservoirs • Capillaries—serve as exchange vessels for nutrients, wastes, and fluids • Veins—collect blood for return to the heart; low-pressure flow of blood (compared to arteries)

  8. Capillary Exchange

  9. Principal Arteries of the Body

  10. Principal systemic arteries. Systemic Arteries

  11. Principal Veins of the Body

  12. Systemic Veins

  13. Disorders of Blood Vessels • Disorders of arteries—arteries must withstand high pressure and remain free of blockage • Arteriosclerosis—hardening of arteries caused by calcification of fatty deposits on arterial walls • Reduces flow of blood, possibly causing ischemia that may progress to necrosis (or gangrene) • May be corrected by vasodilators (vessel-relaxing drugs) or angioplasty (mechanical widening of vessels), or surgical replacement • Atherosclerosis—lipids and other matter block arteries

  14. Partial Blockage of an Artery in Atherosclerosis

  15. Balloon Angioplasty

  16. Disorders of Arteries • Aneurysm—abnormal widening of arterial wall • Promotes formation of thrombi that may obstruct blood flow to vital tissues • Arterial walls may burst, resulting in life-threatening hemorrhaging • Cerebrovascular accident (CVA) or stroke—ischemia (reduced blood flow) of brain tissue caused by embolism or hemorrhage

  17. Disorders of Veins • Veins are low-pressure vessels • Varicose veins (varices)—enlarged veins in which blood pools • Hemorrhoids are varicose veins in the rectum • Treatments include supporting affected veins and surgical removal of veins • Thrombophlebitis—vein inflammation (phlebitis) accompanied by clot (thrombus) formation; may result in fatal pulmonary embolism

  18. Varicose Veins

  19. Circulation of Blood • Systemic and pulmonary circulation • Blood circulation—refers to the flow of blood through all the vessels, which are arranged in a complete circuit or circular pattern • Systemic circulation • Carries blood throughout the body • Path goes from left ventricle through aorta, smaller arteries, arterioles, capillaries, venules, venae cavae, to right atrium

  20. Diagram of Blood Flow in the Circulatory System

  21. Pulmonary & Hepatic Portal Circulation • Pulmonary circulation • Carries blood to and from the lungs • Arteries deliver deoxygenated blood to the lungs for gas exchange • Path goes from right ventricle through pulmonary arteries, lungs, pulmonary veins, to left atrium • Hepatic portal circulation • Unique blood route through the liver • Vein (hepatic portal vein) exists between two capillary beds • Assists with homeostasis of blood glucose levels • Stores glycogen and detoxifies the blood

  22. Hepatic Portal Circulation

  23. Fetal Circulation • Refers to circulation before birth • Modifications required for fetus to efficiently secure oxygen and nutrients from the maternal blood • Unique structures include the placenta, umbilical arteries and vein, ductusvenosus, ductusarteriosus, and foramen ovale

  24. The Fetal Circulation

  25. Changes to Fetal Circulation at Birth • Baby's specialized fetal blood vessels must stop working • When newborn first breathes air, the pressure exerted closes off those vessels and the foramen ovale • If the foramen ovalefails to close, ATRIAL SEPTAL DEFECT (ASD)occurs, creating a lack of oxygen • Resulting bluish tint is called cyanosis

  26. Congenital heart defects.

  27. Circulation Physiology • Blood exchanges oxygen, carbon dioxide, other substances generated by cells. • Tissue fluid (interstitial fluid) is the exchange medium.

  28. Circulation Physiology (cont.) Capillary Exchange • How substances move between cells and capillary blood • Diffusion • Main process • Blood pressure • Moves material into the interstitial fluid (filtration) • Osmotic pressure • Moves material from the interstitial fluid back into capillaries (osmosis)

  29. The role of capillaries. Circulation Physiology

  30. Circulation Physiology (cont.) Return of Blood to the Heart • Mechanisms that promote blood’s return to the heart • Contraction of skeletal muscles • Valves in the veins • Breathing

  31. Blood return. Circulation Physiology (cont.)

  32. Blood Pressure and Hypertension, Pulse Points, and Circulatory Shock Identify and discuss the factors involved in the generation of blood pressure and how they relate to each other. Define pulse and locate the major pulse points on the body. Define hypertension and its associated risk factors and complications. Explain what is meant by the term circulatory shock and describe the major types. Lesson 15.2

  33. Blood Pressure • Defining blood pressure • “Push” or force of blood in the blood vessels • Exists in all blood vessels—highest in arteries, lowest in veins • Blood pressure gradient—causes blood to circulate; liquids can flow only from areas of high pressure to areas of low pressure • Hypotension- Low or nonexistent blood pressure gradient is fatal if not reversed • Hypertension- (high blood pressure) can cause a blood vessel to rupture

  34. Pressure Gradients in Blood Flow

  35. Factors that Influence Blood Pressure • Blood volume—the larger the volume, the more pressure is exerted on vessel walls • Strength of heart contractions—affect cardiac output; stronger heartbeat increases pressure; weaker beat decreases it • Heart rate—increased rate increases pressure if the stroke volume does not decrease (decreased stroke volume from incomplete filling of the left ventricle will decrease the blood pressure); decreased rate decreases pressure

  36. Blood Viscosity and Resistance to Flow • Blood viscosity (thickness)—less than normal viscosity decreases pressure; more than normal viscosity increases pressure • Resistance to blood flow (peripheral resistance)—affected by many factors, including the vasomotor mechanism (vessel muscle contraction/relaxation)

  37. Vasomotor Mechanism

  38. Fluctuations in Blood Pressure • Blood pressure varies within normal range from time to time • Central venous pressure—influences pressure in large peripheral veins • Venous return of blood to the heart depends on five mechanisms • A strongly beating heart • An adequate arterial blood pressure • Valves in the veins • Pumping action of skeletal muscles as they contract • Changing pressures in the chest cavity caused by breathing

  39. Pulse Definition—alternate expansion and recoil of the blood vessel wall Nine major pulse points named after arteries over which they are felt

  40. Pulse Points

  41. Hypertension (HTN) Occurs when blood pressure exceeds 140/90 mm Hg Ninety percent of HTN cases are primary essential (idiopathic); secondary HTN can be caused by kidney disease or other causes Many risk factors for HTN, including genetics, age, stress, obesity, and more Untreated HTN may contribute to heart disease, kidney failure, and stroke

  42. Classification of Hypertension

  43. Circulatory Shock Failure of the circulatory system to deliver oxygen to the tissues adequately, resulting in cell impairment Cardiogenic shock—caused by heart failure

  44. Hypovolemic Shock Drop in blood volume that causes blood pressure (and blood flow) to drop Often caused by hemorrhage or loss of interstitial fluid, causing blood plasma to drain out of the vessels

  45. Negative Feedback

  46. Neurogenic Shock Caused by nerve condition that relaxes (dilates) blood vessels and thus reduces blood flow Occurs when sympathetic stimulation is disrupted

  47. Anapyhlactic Shock Results from an acute allergic reaction called anaphylaxis Causes the same kind of blood vessel dilation that occurs in neurogenic shock

  48. Septic Shock Results from complications of septicemia (toxins in blood resulting from infection) Toxins dilate blood vessels, inducing shock

More Related