Vesels and Circulation Part 1 Flashcards
What vessel returns blood to the heart from capillaries?
Venules
It is known that arteries become progressively smaller as they divide and get further from the heart, but what can be said about veins as they get closer to the heart?
Veins become progressively larger as they merge and get closer to the heart.
What is an anastomosis?
Site where two or more vessels merge to supply the same body region is called an anastomosis.
What type of anatomoses can provide alternate blood supply routs to tissues or organs?
An arterial anatomoses.
What is an anatomical end artery? Why is it extremely detrimental if they become blocked?
Anatomical end arteries are vessels whose terminal branches do not anastomose.
- examples would be kidneys, spleen, and brain
In the event that these vessels become blocked (atherosclerosis, blood clot) the tissues will be deprived of oxygen and an “infarct” develops (e.g., kidneys, spleen, brain).
Give an example of a functional end artery and the definition?
Example: Coronary Artery
Functional End Arteries -> anastomoses are so small that arteries may be considered end arteries.
True or False:
Veins tend to form many more anastomoses than do arteries.
True
What are the three layers that make up an artery?
tunica intima
tunica media
tunica externa
Which tunica of an artery is composed of a layer of endothelium?
Tunica Intima (tunica interna)
In what layer of the artery is smooth muscle found? Is this layer under autonomic control?
Tunica Media -> composed of circularly arranged layers of smooth muscle cells, which are under autonomic control.
What is the tunica externa (tunica adventitia) typically composed of?
- areolar connective tissue (loose connective tissue)
- elastic fibers
- collagen fibers
- nerve fibers
What is a vasa vasorum?
Small blood vessels that supply the cells of the wall.
Elastic and Collagen Fibers are found in higher concentration in the artery or vein tunics?
The Artery has more elastic and collagen fibers found in the tunics.
True or False:
The thickest tunic of the artery is the tunica externa.
False, the thickest tunic of the artery is the tunica media. The thickest tunic of veins is the tunica externa.
What cross-sectional shape would you expect to see when looking at a vein?
Cross-sectional view of a vein tends to be flattened and collapsed.
What shape would you find an artery when looking at a cross-sectional cut?
Arteries typically retain circular cross-sectional shape.
When comparing arteries and veins, which one typically has a narrower lumen diameter?
An artery has a narrower than vein lumen diameter.
What are the 3 basic types of arteries and what bases are they classified on?
1) Elastic Arteries
2) Muscular Arteries
3) Arterioles
They are classified on size and function.
Is the diameter of an artery directly or indirectly related to smooth muscle concentration?
Indirectly, as an artery’s diameter decreases there is a relative increae in the amount of smooth muscle.
What happens to the amount of elastic fibers found in arteries as the diameter of an artery decreases?
As the artery’s diameter decreases, there is a corresponding decrease in the amount of elastic fibers.
Give three examples of elastic arteries found in the body?
aorta pulmonary arteries brachiocephalic trunk common carotid common iliac
What 2 primary properties do elastic arteries posses?
1) Dampen blood pressure changes associated with heart contractions
2) Passive accommodation results in smooth flow of blood
Of the 3 types of arteries, which type are considered conducting arteries?
Elastic Arteries (thick-walled, near heart; high production of elastic fibers throughout tunica media)
When comparing the location of elastic fibers between muscular and elastic arteries, what area are elastic fibers restricted to in muscular arteries but not in elastic arteries.
Muscular Arteries –> elastic fibers restricted to internal and external elastic lamina
Elastic Arteries –> elastic fibers found all throughout tunica media