#17 Blood Vessels

Question 1

functions of arteries

Answer 1

Transport blood away from the heart

Carry oxygen-rich blood in the systemic circuit

Carry oxygen-poor blood in the pulmonary circuit and umbilical arteries

Anastomosis: Two or more arteries converge to supply the same body region

Question 2

function of capillaries

Answer 2

Location of gas and nutrient exchange between blood and tissues

Question 3

Function of veins

Answer 3

Transport blood towards the heart

Carry oxygen-poor blood in the systemic circuit

Carry oxygen-rich blood in the pulmonary circuit and umbilical vein

Question 4

anastomosis

Answer 4

Two or more arteries converge to supply the same body region

Question 5

tunica intima

Answer 5

Simple squamous epithelium called “endothelium”

Question 6

tunica media

Answer 6

Circularly arranged smooth muscle fibers

Location of vasodilation (lumen becomes larger) and vasoconstriction (lumen becomes smaller)

Question 7

Tunica externa

Answer 7

Collagen and elastic fibers

Contains the vaso vasorum

Question 8

tunics in arteries

Answer 8

Thick walls, small lumens

Thickest layer is tunica media

Question 9

tunics in capillaries

Answer 9

Very small lumen (only one RBC at a time)

Only tunica intima

Allow rapid gas exchange

Question 10

veins in arteries

Answer 10

Thin walls, large lumens

Thickest layer is tunica externa

Valves

Question 11

Arteries vs. Veins

Answer 11

Both have tunica intima

Veins have a larger lumen than arteries

Tunica media = smooth muscle

Tunica media of artery is larger than vein. (giving it a better ability to vasoconstrict

Tunica externa = largest layer of vein

Artery = tunica media = largest (layer)

Question 12

elastic arteries

Answer 12

Largest artery

Conducting arteries

Between heart and muscular arteries

High elastin content

Stretch and recoil to dampen blood pressure changes resulting from contractions of heart

Aorta and its major branches

Brachiocephalic, common carotid, subclavian, common iliac arteries etc.

Question 13

muscular arteries

Answer 13

Distributing arteries

Distribute blood to the body organs

Thick tunica media

Diameter of lumen changes to regulate amount of blood flow to organs

Most of the named arteries seen in lab

Brachial, femoral, coronary, inferior mesenteric arteries, etc.

Question 14

arterioles

Answer 14

Diameter is regulated by

Local tissue factors

Sympathetic nervous system

Question 15

capillaries

Answer 15

Smallest vessels

Endothelium only

Gas, nutrient and waste exchange

Question 16

venules

Answer 16

Smallest veins • Primary location of diapedesis

Question 17

types of capillaries

Answer 17

continuous capillary, fenestrated capillary, sinusoidal capillary

Question 18

continuous capillary

Answer 18

Most common type

Muscle skin thymus lungs

Question 19

fenestrated capillary

Answer 19

Small intestine, kidneys, most endocrine glands

Question 20

sinusoidal capillary

Answer 20

Bone marrow, spleen, liver

Allows for bigger structures to get in the blood (like proteins)

Question 21

structure / function of veins

Answer 21

Return blood to the heart

Act as blood reservoir

Low blood pressure in veins

Walls of veins are thinner than those of comparable arteries

Most veins contain valves

Valves prevent backflow of blood

Skeletal muscle contractions help pump blood toward the heart

Question 22

pre-natal circulation

Answer 22

umbilical cord, ductus venosus, foramen ovale, ductus arteriosus

Question 23

umbilical cord pre natal

Answer 23

Two umbilical arteries

One umbilical vein

Question 24

ductus venosus pre natal

Answer 24

Takes blood from umbilical vein to the inferior vena cava (keeps it away from the liver sinusoids)

Question 25

foramen ovale pre natal

Answer 25

Diverts blood from the right atrium to the left atrium

Question 26

ductus arteriosus pre natal

Answer 26

Diverts blood from the pulmonary trunk to the aortic arch

Question 27

Post Natal Circulation

Answer 27

umbilical cord, ductus venosus, foramen ovale, ductus arteriosus

Question 28

umbilical cord for post-natal

Answer 28

Two umbilical arteries (become medial umbilical ligaments) One umbilical vein (becomes the round ligament of the liver)

Question 29

ductus venosus post-natal

Answer 29

becomes the legamentum venosum

Question 30

foramen ovale post-natal

Answer 30

becomes fossa ovalis

Question 31

ductus arteriosus post natal

Answer 31

becomes the ligamentum arteriosum

Question 32

atherosclerosis

Answer 32

Progressive disease of the elastic and muscular arteries Often the aorta and coronary arteries Atheroma (fatty plaque) Thickening of the tunica intima and narrowing of the arterial lumen

Question 33

aneurysm

Answer 33

Abnormal dilation of an artery • Can rupture, causing hemorrhage

Question 34

cerebrovascular accident (stroke)

Answer 34

Commonly known as a stroke Caused by a ruptured aneurysm or blockage of a brain blood vessel Thrombus: a blood clot that forms within the brain blood vessel Embolus: a blood clot formed in another blood vessel that migrates to the brain Can lead to death of brain tissue

Question 35

varicose veins

Answer 35

Dysfunctional valves leads to blood pooling in the superficial limb veins Result of genetic predisposition, aging, or strain that inhibits venous return - Hemorrhoids: varicose veins of the anorectal region caused by increased intra-abdominal pressure