A&PII Lab 6: The Cardiovascular System - The Blood Vessels

Question 1

Tunica interna (tunica intima)

Answer 1

innermost layer of arteries; simple squamous epithelium that establishes a smooth inner surface of the vessel

Question 2

Endothelium

Answer 2

smooth inner surface of arteries

Question 3

Basement membrane

Answer 3

connective tissue portion of arteries

Question 4

Internal elastic membrane

Answer 4

thin elastic connective tissue layer of arteries; enables the lumen of the vessel to stretch open to accommodate surges in blood volume that occur during the cardiac cycle

Question 5

Tunica media

Answer 5

bordering the internal elastic membrane in arteries; thickest layer; contains smooth muscle cells and elastic fibers

Question 6

Vasoconstriction

Answer 6

contraction of the smooth muscle causing a decrease in the diameter of the lumen

Question 7

Vasodilation

Answer 7

relaxation of the smooth muscle causing a relaxation and an increase in the lumen diameter

Question 8

Tunic externa (tunica adventitia)

Answer 8

outermost layer of an artery wall; composed of loose connective tissue that provides support and protection; its collagen fibers anchor arteries to nearby structures

Question 9

Elastic arteries

Answer 9

the largest arteries; named so due to the large amount of elastic fibers present in the tunica media; must stretch under the pressure exerted during ventricular contraction to accommodate a large bolus of blood with each cardiac cycle

Question 10

Muscular arteries

Answer 10

smaller tributaries from the elastic arteries; more smooth muscle cells and fewer elastic fibers in the tunica media

Question 11

External elastic membrane

Answer 11

the elastic fibers are concentrated to form this distinct layer between the tunica media and tunica externa

Question 12

Arterioles

Answer 12

after branching into smaller tributaries, the muscular arteries eventually give rise to small arteries, and finally these, which carry blood to capillaries

Question 13

Capillary networks

Answer 13

capillaries are usually found in these complex branching patterns

Question 14

Precapillary sphincters

Answer 14

tiny sphincter muscles of smooth muscle are present at this union between the arteriole and capillary

Question 15

Venules

Answer 15

small tubes that are intermediary between capillaries and larger veins; wall consists of a thin endothelium and a tunica media with only a few smooth muscle cells

Question 16

Veins

Answer 16

venules converge to form these larger vessels; 3 tunics; however, the thickness of the wall is much thinner in these, and the lumen is much larger

Question 17

Valves

Answer 17

one-way extensions of the tunic intima; present in the veins of the limbs and elsewhere to prevent the backflow of blood

Question 18

Systemic circulation

Answer 18

primary blood delivery system of the body, carrying oxygenated blood from the heart to all body tissues except the lungs; also includes the capillaries within all tissues of the body except the lungs, and the veins outside of the lungs that carry deoxygenated blood back to the right atrium

Question 19

Pulmonary circulation

Answer 19

route of blood flow to the lungs from the right ventricle, the capillary distribution within the lungs, and the vessels that carry oxygenated blood from the lungs to the left atrium

Question 20

Hepatic portal circulation

Answer 20

blood is carried from the large intestine, small intestine, stomach, spleen, and pancreas to the liver

Question 21

Placenta

Answer 21

the exchange between mother and fetus is made possible by the presence of this, which contains capillaries from the mother

Question 22

Umbilical vein

Answer 22

vein that carries oxygen-rich blood through the umbilical cord to the fetus

Question 23

Ductus venosus

Answer 23

within the fetus, this vessel carries blood from the umbilical vein to the inferior vena cava

Question 24

Foramen ovale

Answer 24

in order to bypass circulation to the lungs, this hole permits blood to flow between the atria

Question 25

Ductus arteriosus

Answer 25

shunts blood from the pulmonary trunk into the aorta

Question 26

Umbilical arteries

Answer 26

to remove deoxygenated blood, 2 of these arteries channel it from their origin at the internal iliac arteries, through the umbilical cord, and to the placenta