Anatomy Physiology SIXTH EDITION Chapter 21 part 2

Anatomy & Physiology SIXTH EDITION Chapter 21, part 2 Blood Vessels and Circulation Power. Point® Lecture Slide Presentation prepared by Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Frederic H. Martini Fundamentals of

Arterial blood pressure • Maintains blood flow through capillary beds • Rises during ventricular systole and falls during ventricular diastole • Pulse is a rhythmic pressure oscillation that accompanies each heartbeat • Pulse pressure = difference between systolic and diastolic pressures Mean arterial pressure (MAP) Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Figure 21. 10 Pressures within the Cardiovascular System Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 21. 10

Figure 21. 10 Pressures within the Cardiovascular System Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 21. 10

Capillary Exchange • Flow of water and solutes from capillaries to interstitial space • Plasma and interstitial fluid are in constant communication • Assists in the transport of lipids and tissue proteins • Accelerates the distribution of nutrients • Carries toxins and other chemical stimuli to lymphoid tissues Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Processes that move fluids across capillary walls • Diffusion • Filtration • Hydrostatic pressure (CHP) • Reabsorption Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Figure 21. 12 Capillary Filtration Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 21. 12

Figure 21. 12 Capillary Filtration Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 21. 12

Forces acting across capillary walls • Capillary hydrostatic pressure (CHP) • Blood colloid osmotic pressure (BCOP) • Interstitial fluid colloid osmotic pressure (ICOP) • Interstitial fluid hydrostatic pressure (IHP) Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Filtration and reabsorption • Processes involved in filtration and reabsorption include • Net hydrostatic pressure • CHP - IHP • Net colloid osmotic pressure • BCOP - ICOP Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Figure 21. 13 Forces Acting across Capillary Walls Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 21. 13

Venous pressure and venous return • Assisted by two processes • Muscular compression • The respiratory pump PLAY Animation: Factors that Affect Blood Pressure Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

SECTION 21 -3 Cardiovascular Regulation Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Cardiovascular Regulation • Autoregulation • Neural mechanisms • Endocrine mechanisms Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Autoregulation of blood flow within tissues • Local vasodilators accelerate blood flow in response to: • Decreased tissue O 2 levels or increased CO 2 levels • Generation of lactic acid • Release of nitric acid • Rising K+ or H+ concentrations in interstitial fluid • Local inflammation • Elevated temperature Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Figure 21. 14 Homeostatic Adjustments that Compensate for a Reduction in Blood Pressure and Blood Flow Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 21. 14

Figure 21. 14 Homeostatic Adjustments that Compensate for a Reduction in Blood Pressure and Blood Flow Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 21. 14

Neural Mechanisms • Adjust CO and PR to maintain vital organ blood flow • Medullary centers of regulatory activity include • Cardiac centers • Vasomotor centers control • Vasoconstriction via adrenergic release of NE • Vasodilation via direct or indirect release of NO Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Reflex control of cardiovascular function • Baroreceptors reflexes monitor stretch • Atrial baroreceptors monitor blood pressure • Chemoreceptor reflexes monitor CO 2, or p. H levels PLAY Animation: Autoregulation and Capillary Dynamics Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Figure 21. 15 Baroreceptor Reflexes of the Carotid and Aortic Sinuses Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 21. 15

Figure 21. 16 The Chemoreceptor Reflexes Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 21. 16

Hormones and cardiovascular regulation • Antidiuretic hormone – released in response to decreased blood volume • Angiotensin II – released in response to a fall in blood pressure • Erythropoietin – released if BP falls or O 2 levels are abnormally low • Natriuretic peptides – released in response to excessive right atrial stretch Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings

Figure 21. 17 The Regulation of Blood Pressure and Blood Volume Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 21. 17 a

Figure 21. 17 The Regulation of Blood Pressure and Blood Volume Copyright © 2004 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 21. 17 b