pg 1 Flashcards
(18 cards)
What is the primary function of the circulatory system?
To bring nutrients to and take wastes away from cells
What are the five types of blood vessels in the circulatory system?
- Arteries
- Arterioles
- Capillaries
- Veins
- Venules
What do arteries do?
Carry blood away from the heart
What is the structure of arteries?
Thick, muscular walls
What are arterioles?
Small branches of arteries
What are capillaries?
Narrow, microscopic tubes with walls one cell layer thick
What occurs at the capillary walls?
Exchange of gases and small molecules like glucose
What are sphincter muscles?
Muscles that encircle the entrance to each capillary
What do veins and venules do?
Take blood from the capillaries back to the heart
What is the function of venules?
Drain blood from capillaries and join to form a vein
What is the structure of veins compared to arteries?
Thinner walls and contain valves
What is the purpose of valves in veins?
Allow blood to flow only toward the heart and prevent backward flow
Fill in the blank: Capillaries connect _______ to venules.
Arterioles
True or False: The walls of veins are thicker than those of arteries.
False
What is the lumen size of capillaries?
Very small
What type of muscle is found in the walls of arteries?
Smooth muscle
What structural feature do veins have that arteries do not?
Valves
What type of blood vessel has walls that are one cell layer thick?
Capillaries
