Functional Anatomy of Blood Vessels Flashcards
What do arteries do?
carry blood away from the heart
What do veins do?
returns blood to heart
Where does blood flow in order?
Starts at right atrium, pulmonary circuit, left atrium, then systemic circuit.
What does the pulmonary circuit consist of?
Pulmonary arteries, capillaries in lungs, pulmonary veins
What does the systemic system consist of?
Capillaries in head, neck, and upper limbs
________ is the chamber of the heart into which systemic blood is returned
Right atrium
________ is the chamber of the heart into which pulmonic blood is returned
Left atrium
Describe the features of arteries
Arteries typically are round vessels with thick walls. The smooth muscle layer in arteries contains many elastic fibers
Describe the features of veins
Veins are typically flattened or collapsed with relatively thin walls. The smooth muscle layer is much thinner and does not contain elastic fibers.
What is tunica intima
endothelial lining of the vessel
What is tunica media
muscular wall of the vessel
What is adventitia or externa
outermost connective tissue sheath
A typical capillary consists of?
a tube of endothelial cells in a single layer. There is no tunica media or tunica adventitia (externa). In many cases, the diameter of the capillary is no larger than the diameter of a single red blood cell.
Describe continuous capillaries
Continuous capillaries have a complete endothelial lining. They permit the diffusion of water, small solutes, and fat-soluble material into tissue fluids.
Describe fenestrated capillaries
Fenestrated capillaries contain windows or pores that permit rapid exchange of water and larger solutes between blood and tissue fluids
Vesicles transport some materials across the capillary endothelial cell cytoplasm
Vesicles transport some materials across the capillary endothelial cell cytoplasm
Which direction does transport and diffusion go in capillaries?
both directions
What are pores called in capillaries
fenestrations
Valves ________ to the contracting muscle open and allow blood to move toward the heart
superior
Valves ________ to the contracting muscle close preventing backflow of blood to capillaries
inferior
Blood pressure in veins is low; low enough to the point where it cannot overcome gravity. In the arms and legs, veins contain valves that function to:
- Compartmentalize blood within veins so it doesn’t all pool at the bottom
- Permit blood flow in only one direction preventing backflow
What are veins called that are enlarged and twisted?
Varicose veins
What system contains 2/3 of the blood in the body?
systemic venous system
What is it called when there is contraction of smooth muscle in the walls of veins?
venoconstriction
What is the distribution of blood throughout the body
64%-systemic venous system 9%-pulmonary circuit 7%-heart 13%-systemic arterial system 7%-systemic capillaries
If serious hemorrhage (loss of blood) occurs, venoconstriction (contraction of smooth muscle in the walls of veins) reduces the diameter of veins (and, therefore, the amount of blood in the venous system), redistributing blood to maintain blood volume in the arterial system.
If serious hemorrhage (loss of blood) occurs, venoconstriction (contraction of smooth muscle in the walls of veins) reduces the diameter of veins (and, therefore, the amount of blood in the venous system), redistributing blood to maintain blood volume in the arterial system.
What is the term used to describe loss of blood?
hemorrhage
What does pulmonary mean?
Lungs
