Transcript Anatomy & Physiology SIXTH EDITION Chapter 21, part 1 Blood Vessels and Circulation PowerPoint® Lecture Slide Presentation prepared by Dr.

Anatomy & Physiology
SIXTH EDITION
Chapter 21, part 1
Blood Vessels and Circulation
PowerPoint® 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
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
Structure of vessel walls
• Walls of arteries and veins contain three distinct
layers
• Tunic intima
• Tunica media
• Tunica externa
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 21.1 A Comparison of a Typical Artery
and a Typical Vein
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Figure 21.1
Differences between arteries and veins
• Compared to veins, arteries
• Have thicker walls
• Have more smooth muscle and elastic fibers
• Are more resilient
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Arteries
• 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
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Capillaries
• 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
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 21.2 Histological Structure of Blood
Vessels
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Figure 21.2
Figure 21.4 Capillary Structure
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Figure 21.4
Capillary Beds
• An interconnected network of vessels consisting
of
• Collateral arteries feeding an arteriole
• Metarterioles
• Arteriovenous anastomoses
• Capillaries
• Venules
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 21.5 The Organization of a Capillary Bed
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 21.5a, b