Blood Vessel Anatomy

Starter- write your answer!

• Explain how this patient’s cardiac output would be affected (if at all) by the electrical activity in their heart.

• Use the terms: – starling’s law– stroke volume– cardiac output

Essentials of Human Anatomy and Physiology, 9eby Elaine N. Marieb

Copyright © 2009 Pearson Education, Inc.,publishing as Pearson Benjamin Cummings.

Figure 11.9b  Structure of blood vessels. (b) The walls of arteries and veins are composed of three tunics: the tunica intima (endothelium underlain by a basement membrane), tunica media (smooth muscle and elastic fibers), and tunica externa (largely collagen fibers).

Tunica intima• Endothelium

• Loose connective tissue

Tunica media

Tunica externa

Artery VeinLumen Lumen

Internal elastic lamina

External elastic lamina

Valve

Endothelium

Capillarynetwork

Capillary

ArterioleVenule

Basementmembrane

(b)

Essentials of Human Anatomy and Physiology, 9eby Elaine N. Marieb

Copyright © 2009 Pearson Education, Inc.,publishing as Pearson Benjamin Cummings.

Essentials of Human Anatomy and Physiology, 9eby Elaine N. Marieb

Copyright © 2009 Pearson Education, Inc.,publishing as Pearson Benjamin Cummings.

Figure 11.9b  Structure of blood vessels. (b) The walls of arteries and veins are composed of three tunics: the tunica intima (endothelium underlain by a basement membrane), tunica media (smooth muscle and elastic fibers), and tunica externa (largely collagen fibers).

Tunica intima• Endothelium

• Loose connective tissue

Tunica media

Tunica externa

Artery VeinLumen Lumen

Internal elastic lamina

External elastic lamina

Valve

Endothelium

Capillarynetwork

Capillary

ArterioleVenule

Basementmembrane

(b)

Veins• Veins have valves to prevent

backflow of blood

• Prevent pooling– Pooling can create a clot that

can get stuck in the pulmonary artery (pulmonary embolism)

• Skeletal muscle contractions help venous return

https://www.youtube.com/watch?v=49jUyBu4M1Q&list=LPW8ZlZW8ZoPE&index=1&feature=plcp

Vericose Veins• Common in people who– stand for long periods of time– are obese or pregnant

• Occur when blood pools in the veins due to inactivity or low venous pressure

https://www.youtube.com/watch?v=7Qs6iWSGzZE&feature=related start at 25 sec

Cover the section on arthrosclerosis and

arteriolesclerosis (on study guide)

Capillary Beds (see fig. 11-11 in book)

• Precapillary sphincters- ring of smooth muscle, regulates blood flow through capillary beds– When open blood flows into

capillaries diffusion occurs – When closed blood flows

from arteriole to venule no diffusion occurs