PhysiologyLesson 1 of 2 in the course The Cardiovascular System: Blood Vessels and Circulation

Blood Vessel Structure, Exchange, and Flow Regulation

5 flashcards · 5 quiz questions · 5 match pairs · 5 fill-in sentences · English

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Summary

Blood vessels form the routes through which blood travels between the heart and the tissues. This lesson introduces the sequence of vessels, the systemic and pulmonary circuits, and structural features shared by arteries and veins.

Blood leaving the heart travels through arteries, which branch into smaller arteries and then into arterioles. Arterioles deliver blood to microscopic capillaries, where gases, nutrients, wastes, and other substances are exchanged with tissues. Capillaries join into venules, which combine to form larger veins. Veins return blood to the heart.

All flashcards

What is the general route of blood through the vessels?
Blood travels from arteries to arterioles, then through capillaries, into venules, and finally through veins toward the heart.
How are arteries and veins defined?
Arteries carry blood away from the heart. Veins carry blood toward the heart, regardless of the blood’s oxygen content.
What are the three vessel-wall tunics, from inner to outer?
Tunica intima, tunica media, and tunica externa.
How do elastic arteries help maintain blood flow between heartbeats?
They expand when blood is ejected from the heart and recoil afterward, helping sustain forward flow.
What is venous capacitance?
The ability of veins to expand and hold a large volume of blood at relatively low pressure.

Quiz questions

  1. What defines an artery, regardless of the oxygen content of its blood?Answer: It carries blood away from the heart.
  2. Which vessels carry oxygen-poor blood from the heart to the lungs?Answer: Pulmonary arteries
  3. Which vessel-wall tunic is generally thickest in arteries and contains smooth muscle that changes lumen diameter?Answer: Tunica media
  4. How does recoil in elastic arteries help circulation?Answer: It helps maintain a pressure gradient and forward flow between heartbeats.
  5. Why are arterioles called resistance vessels?Answer: Their narrow, adjustable lumens create substantial resistance to blood flow.

Based on Anatomy and Physiology 2e by J. Gordon Betts, Kelly A. Young, James A. Wise, Eddie Johnson, Brandon Poe, Dean H. Kruse, Oksana Korol, Jody E. Johnson, Mark Womble, Peter DeSaix (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.

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