Blood vessels & circulation

In blood vessel anatomy, the term lumen refers to the:

space within the vessel where blood flows

the tunica intima is the vessel layer that:

lines the lumen, includes an endothelium of simple squamous epithelium.

capillaries are unique because they are composed of:

tunica intima only

vasoconstriction and vasodilation occur primarily in the:

tunica media

what is vasoconstriction?

contracts/decrease vessel diameter

what is vasodilation?

relaxes/increase vessel diameter

the tunica externa is best described as:

the outermost layer that is strong and elastic, important for handling pressure

arteries are defined functionally as vessels that:

carry blood away from the heart

veins are defined functionally as vessels that:

carry blood towards the heart

elastic (conducting) arteries help stabilize blood flow because they:

expand during systole and recoil during diastole

what is systole?

when the heart contracts and pumps blood out

what is diastole?

when the heart relaxes and fills with blood

what is the ideal blood pressure?

120/80:

• 120 = systolic pressure (during contraction)

• 80 = diastolic pressure (during relaxation)

which vessel is an example of an elastic artery listed in the lecture?

aorta

muscular (distributing) arteries are characterized by:

thick walls with many layers of smooth muscle that help regulate regional blood supply

arterioles are important because they:

regulate blood flow into capillaries and are primary vessels for regulating systemic blood pressure

an aneurysm is best described as:

a blowout blister within an artery

an anastomosis is important because it provides:

collateral circulation (alternate routes for blood flow)

the cerebral arterial circle (circle of willis) is an example of:

an arterial anastomosis at the base of the brain

capillaries are the primary site of exchange because they:

have thin walls and allow transport of materials between blood and tissues

which capillary type has pores (fenestrations) and is more permeable than continuous capillaries?

fenestrated capillaries

blood flow into a capillary bed is regulated by:

precapillary sphincters

sinusoids (sinusodial capillaries) are distinguished by

large fenestrations that allow molecules or whole cells to pass

valves are present in veins (typically >2mm in diameter) primarily to:

help ensure one way blood flow, against gravity

varicose (spider) veins occur when:

blood pools due to malfunctioning venous valves

what percentage of total blood volume is found in the veins (as described in lecture)?

60%

the hepatic portal system is best described as:

a system of veins that carry nutrient rich blood from the intestines to the liver for processing.

systemic circulation is the route blood takes from the:

left side of the heart to the body and back to the right side of the heart.

pulmonary circulation is the route blood takes from the:

right side of the heart to the lungs and back to the left side of the heart.

starting at the heart, the parts of the aorta are correctly listed in order as:

ascending aorta, aortic arch, descending aorta