Arteries Flashcards
What “branches, diverges, and forks”
Arteries
What is a smaller artery?
Arteriole
What “joins, merges, converges”?
Veins
What is a smaller vein?
Venule
What happens at capillaries?
Exchange of O2, CO2, nutrients, and waste
What is the vasculature of vessels called?
Vasa vasorum
What does the vasa vasorum do?
Supplies big arteries and veins with their own blood supply
Since there is a continuous ________ in size and character of the vessel wall from the largest arteries down to the capillaries, some layers that were present in the arteries begin to diminish/disappear as they get closer to _____ size.
Gradation
Capillary
What are the three layers that compose the walls of blood vessels?
Tunica adventitia
Tunica media
Tunica intima
What is the outer layer of blood vessels?
Tunica adventitia
What kind of tissue and fibers make the tunica adventitia?
Connective tissue
Elastic and collagen fibers
The tunica adventitia merges with…..
The surrounding CT in the area, eg surrounding structures
What is the middle layer of blood vessels?
Tunica media
What is the tunica media made from?
Either smooth muscle OR elastic fibers
What is the thickest of the three vessel tunics in arteries?
Tunica media
How are the muscles or fibers in the tunica media arranged?
Arranged circularly around vessel
What is the innermost tunic of the blood vessel? What layers make it?
Tunica Intima
Lamina propria
Basement membrane
Endothelium
What is the lamina propria?
Usually just a thin layer of CT
What is the basement membrane?
Thin layer of glycoproteins, GAGS, and collagen fibers
What is the endothelium?
Innermost lining
Simple squamous epithelium
What are the two elastic laminas in the walls of blood vessels? Where are they found?
Internal elastic lamina: Between tunica media and tunica intima
External elastic lamina: Between tunica adventitia and tunica media
What nervous system vasoconstricts?
PNS
What nervous system vasodilates?
SNS
What are the three types of arteries?
Elastic
Muscular
Resistance
What are some examples of elastic arteries?
aorta, subclavian, common carotid
Describe the tunics of an elastic artery
Tunica media contains mostly elastic fibers and some muscle fibers
The elastic lamina is hard to find b/c it’s tough to differentiate it from the elastic fibers
Elastic arteries function as pressure ________
reservoirs
The aorta distends from pressure at each systole, then ________ so blood moves forward in a more or less ________ fashion
Rebounds
Continuous
What two mechanisms provide alternate routes for blood to get to its intended target?
Anastomosis
Collateral circulation
What is an anastomosis?
A natural communication between 2 blood vessels
What is collateral circulation?
A route from non-anastomosing vessels that supply the same area, eg the elbow and knee
What is the generation of new blood vessels?
Angiogenesis
What are three normal types of angiogenesis?
1- Regrowth of uterine lining after menstruation
2-Development of higher-density blood capillaries in muscles of well-conditioned athletes
3- Arterial bypasses around obstructions in coronary circulation
How do tumors get blood?
They do their own angiogenesis
What does a muscular artery do?
Distributes blood throughout the body
What are some examples of muscular arteries?
External carotid, brachial, femoral
And, most of the named arteries
Describe the tunics of a muscular artery
Tunica media contains mostly muscle fibers
What is a resistance artery?
No names, too variable, the smallest ones are arterioles
Name the almost microscopic oxygenated vasculature.
Arteriole
Arterioles take blood from ______ to ______.
Arteries
Capillaries
What kind of fiber surround the basement membrane and endothelium of an arteriole? Why?
Smooth muscle
To vasoconstrict
What does the vasoconstriction of arterioles play a key role in?
Regulating blood flow
In an arteriole, when the smooth muscle contricts, it slows the blood to corresponding ________.
Capillaries
Where is a portal system found?
Posterior pituitary and hepatic(liver to intestine)
