Flashcards in Vesels and Circulation Part 1 Deck (61):
What vessel returns blood to the heart from capillaries?
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.
What are the three layers that make up an artery?
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)
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
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?
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
How many layers of smooth muscle is typically found in the tunica media of an arteriole?
Generally less than 6 layers of smooth muscle in tunica media of arterioles.
What affect does vasoconstriction have on blood flow to capillaries and systemic blood pressure?
Vasoconstriction decrease blood flow to capillaries and increases blood pressure.
What affect does vasodilation have on blood flow to capillaries?
Vasodilation increases blood flow to capillaries.
Name the 4 most common arterial disorders.
Arteriosclerosis (hardening of the arteries)
Atherosclerosis (fatty deposits and occlusion)
Aneurysms (ballooning and/or rupture of the vessel)
What are the 3 main classes of blood vessels?
Arteries, Capillaries, & Veins
What is the primary cause of cardiac infarction and cerebral infarction?
These pathologies result from occlusion of the lumen of arteries and are major causes of morbidity and mortality.
What is atherosclerosis?
A slow, complex disease in which fatty deposits (called plaque) build up in the inner lining of an artery, eventually causing it to narrow and restrict blood flow.
What is the response-to-injury hypothesis?
Repeated injury (infection, trauma, hypertension to endothelium -> inflammatory response -> development of atheroma (placque)
What are the risk factors that have been linked to increased risk of atherosclerosis?
What is the function of capillaries and what two types of vessels do they connect to?
Capillaries allow gas and nutrient exchange between the blood and the body tissues to occur rapidly.
Capillaries connect arterioles to venules.
True or False:
Capillaries have a tunica intima and tunica externa.
False, capillaries only contain the tunica intima (but this layer consists of a basement membrane and endothelium only).
Fill in the blank:
______contain only the tunica intima, but this layer consists of a basement membrane and endothelium only.
What type of capillary is constructed of branches of metarterioles?
What are the three basic kinds of capillaries?
Continuous Capillaries (most common type)
Sinusoids (discontinuous capillaries)
Give two examples of where you would find sinusoid capillaries?
What type of capillaries would you expect to find in the GI tract, kidney, and endocrine glands?
What type of capillaries is the most commonly found in the body? Also, where specifically would you find them?
Continuous Capillaries are the most commonly found type of capillary.
Is found in the muscle, skin, lungs, and CNS.
What type of vein carries deoxygenated blood to the right atrium of the heart?
Systemic veins carry deoxygenated blood to the right atrium of the heart.
Pulmonary veins carry ______ _______ to the left atrium of the heart.
What percent of blood is in the venous system at rest in the body?
Veins hold about 60% of the body's blood at rest.
What vessel in the body functions as a blood reservoirs?
Veins function as blood reservoirs.
At what diameter does a venule become a vein?
What is the thickest layer of a venule?
In venules, is the tunica media made up of primarily elastin or smooth muscle?
Mostly elastin, with little muscle in the tunica media of venules.
Which has thinner walls and less muscle, arteries or venules?
As blood flows superiorly in the limbs, the ___ close to prevent _____ of blood.
What process squeezes deep veins to help pump the blood toward the heart?
Skeletal Muscle Pump
*Many deep veins pass between skeletal muscle groups.
*As the skeletal muscles contract, veins are squeezed to help pump the blood toward the heart
*This process is called the skeletal muscle pump
What malfunction causes varicose veins?
Valves are nonfunctional causing blood to pool.
*dilated, tortuous veins
*most common in lower limb
*genetics, aging, stress (standing, pregnancy, obesity)
What common treatment is typically used to treat varicose veins?
Sclerotherapy -- irritant injected into smaller veins to cause scarring & closure.
Also, vein ablation is a treatment as well.
What is the most serious complication that can present from a deep vein thrombosis?
Where are the two most common regions that deep vein thrombosis occur?
DVT common in sural (calf) or femoral (thigh) region.
What are the 3 leading causes of DVT and what treatment is most commonly used?
Poor Blood Circulation, Venous Injury, and Increased Blood Clotting.
Treatment is anticoagulant for DVT.
What percentage of total blood volume is typically found in the veins in the circulatory system?
What organ in the circulatory system contains the second highest percentage of total blood volume?
The lungs contain 9%, which is second with veins being number 1 at 64%.
True or False:
Hypertension is referring to an acute elevated blood pressure.
Hypertension is referring to a chronically elevated blood pressure.
Is the left or right pulmonary artery longer?
The right pulmonary artery.