Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fundamentals of Anatomy & Physiology SIXTH EDITION Frederic H. Martini PowerPoint ® Lecture Slide Presentation prepared by Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii Chapter 21, part 1 Blood Vessels and Circulation
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Learning Objectives Distinguish among the types of blood vessels. Describe fluid and dissolved material transport into and out of the cardiovascular system. Describe the factors that influence blood pressure and blood pressure regulation. Discuss the mechanisms involved in the movement of fluids between capillaries and interstitial spaces.
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Learning Objectives Describe how blood flow and pressure in tissues is regulated. Identify the principle blood vessels of each circuit and the areas they serve. Describe fetal circulation patterns and the changes that occur in these patterns at birth and during aging.
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 21-1 The Anatomy of Blood Vessels
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Walls of arteries and veins contain three distinct layers Tunic intima Tunica media Tunica externa Structure of vessel walls
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 21.1 Figure 21.1 A Comparison of a Typical Artery and a Typical Vein
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Compared to veins, arteries Have thicker walls Have more smooth muscle and elastic fibers Are more resilient Differences between arteries and veins
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Undergo changes in diameter Vasoconstriction – decreases the size of the lumen Vasodilation – increases the size of the lumen Classified as either elastic (conducting) or muscular (distribution) Small arteries (internal diameter of 30 um or less) are called arterioles Arteries
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings An endothelial tube inside a basal lamina These vessels Form networks Surround muscle fibers Radiate through connective tissue Weave throughout active tissues Capillaries have two basic structures Continuous Fenestrated Flattened fenestrated capillaries = sinusoids Capillaries
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 21.2 Figure 21.2 Histological Structure of Blood Vessels
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 21.4 Capillary Structure Figure 21.4
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings An interconnected network of vessels consisting of Collateral arteries feeding an arteriole Metarterioles Arteriovenous anastomoses Capillaries Venules Capillary Beds
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 21.5 The Organization of a Capillary Bed Figure 21.5a, b
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Collect blood from all tissues and organs and return it to the heart Are classified according to size Venules Medium-sized veins Large veins Veins
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Venules and medium-sized veins contain valves Prevent backflow of blood Venous Valves
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 21.6 Figure 21.6 The Function of Valves in the Venous System
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Total blood volume is unevenly distributed Venoconstriction maintains blood volume Veins are capacitance vessels Capacitance = relationship between blood volume and pressure Distribution of blood Animation: Anatomy Review: Blood Vessel Structure and Function PLAY
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 21.7 Figure 21.7 The Distribution of Blood in the Cardiovascular System
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 21-2 Cardiovascular Physiology
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Circulatory pressure is divided into three components Blood pressure (BP) Capillary hydrostatic pressure (CHP) Venous pressure Circulatory Pressure
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 21.8 Figure 21.8 An Overview of Cardiovascular Physiology
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Resistance of the cardiovascular system opposes the movement of blood For blood to flow, the pressure gradient must overcome total peripheral resistance Peripheral resistance (PR) is the resistance of the arterial system Resistance (R)
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Factors involved in cardiovascular pressures include Vessel diameter Cross-sectional area of vessels Blood pressure Blood viscosity Overview of Cardiovascular Pressures
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 21.9 Figure 21.9 Relationships among Vessel Diameter, Cross-sectional Area, Blood Pressure, and Blood Viscosity