11.21 B

Question 1

What kind of epithelium lines blood vessels?

Answer 1

simple squamous

Question 2

White blood cells typically exit the vascular system at what point?

Answer 2

in the post-capillary venules

Question 3

Elastic arteries are also known as what?

Answer 3

larger arteries

Question 4

Muscular arteries are also known as what?

Answer 4

medium-sized arteries

Question 5

Where in the vascular system does hydrostatic pressure drop the most?

Answer 5

in the arterioles

Question 6

The innermost of the three layers of arterial walls is called what?

Answer 6

tunica intima

Question 7

The outermost of the three layers of arterial walls is called what?

Answer 7

tunica externa or tunica adventitia

Question 8

The middle layer of arterial walls is called what?

Answer 8

tunica media

Question 9

Describe the tunica intima.

Answer 9

• the endothelial lining as well as the subendothelial basement membrane
• loose connective tissue
• a dense layer of elastic fibers

Question 10

The dense layer of elastic fibers in the tunica intima is called what?

Answer 10

the internal elastic lamina

Question 11

Describe the tunica media.

Answer 11

concentric layers of smooth muscle, collagen fibers, and discontinuous elastic sheaths

Question 12

The discontinuous elastic sheaths that help constitute the tunica media are called what?

Answer 12

the external elastic lamina

Question 13

Describe the tunica externa.

Answer 13

connective tissue with it’s own vascular supply and innervations

Question 14

What are vasa vasorum?

Answer 14

blood vessels supplying the tunica externa of larger vessels

Question 15

What are nervi vasorum?

Answer 15

nerves that innervate the tunica externa of large blood vessels

Question 16

What are conducting arteries?

Answer 16

large (aka elastic) arteries that conduct blood from the heart

Question 17

What are distributing arteries?

Answer 17

medium-sized arteries that allow selective distribution of blood to different organs in response to functional needs

Question 18

What feature of the vascular system ensures continuous blood flow despite intermittent pumping of the heart?

Answer 18

the elastic recoil of large arteries during diastole

Question 19

When do large arteries recoil?

Answer 19

during diastole

Question 20

How does the histology of elastic arteries compare to those of muscular arteries?

Answer 20

muscular arteries often have a more prominent internal elastic lamina as well as fewer elastic sheaths and more smooth muscle fibers

Question 21

What are resistance vessels?

Answer 21

arteries that regulate the distribution of blood to different capillary beds by vasoconstriction and vasodilation

Question 22

What type of blood vessel is a major determinant of overall systemic blood pressure?

Answer 22

arterioles

Question 23

How thick is the tunica media of arterioles?

Answer 23

they typically have 2-5 concentric layers of vascular smooth muscle

Question 24

Why do veins tend to appear more irregularly shaped than arteries?

Answer 24

because they have less smooth muscle and elastic tissue because they aren’t under the hydrostatic force generated by the heart

Question 25

What are the three types of capillaries?

Answer 25

continuous, fenestrated, and discontinuous

Question 26

Where are continuous capillaries found?

Answer 26

muscle, brain, thymus, and lung

Question 27

Where are fenestrated capillaries found?

Answer 27

sites of fluid transport like intestine and kidney

Question 28

Where are discontinuous capillaries found?

Answer 28

sites of macromolecule exchange like liver, spleen, and bone marrow

Question 29

Which types of capillaries have an intact basement membrane?

Answer 29

continuous and fenestrated

Question 30

What are caveolae?

Answer 30

vesicles that transport substances through the cytoplasm of endothelial cells lining capillaries

Question 31

What are sinusoids?

Answer 31

the gaps found in discontinuous capillaries

Question 32

Caveolae are coated with what protein?

Answer 32

caveolin

Question 33

What are pericytes involved in?

Answer 33

- tight junction formation - vesicle trafficking in endothelial cells - regulation of blood flow - angiogenesis

Question 34

Loss of pericytes in the CNS result in what?

Answer 34

loss of the blood brain barrier and neurodegenerative disorders

Question 35

What types of blood vessels tend to be lined by pericytes?

Answer 35

arterioles and venules

Question 36

How do the tunica of veins compare to those of equal sized arteries?

Answer 36

- no distinct internal elastic lamina in veins | - tunica media of veins are typically thinner

Question 37

What is prostacyclin?

Answer 37

a compound produced by endothelial cells to limit adhesion of platelets to the cells, preventing clotting

Question 38

How do endothelial cells modulate smooth muscle activity?

Answer 38

by producing nitric oxide (a muscle relaxant) and endothelin 1 (a muscle contractor)

Question 39

What is endothelin 1?

Answer 39

a muscle contractor produced by endothelial cells to regulate smooth muscle activity

Question 40

What is Tissue Factor?

Answer 40

a compound that initiates blood clotting

Question 41

What are some active roles of endothelial cells?

Answer 41

- modulate smooth muscle activity - produce prostacyclin - trigger blood coagulation - traffic inflammatory cells - control vascular cell growth

Question 42

How does oxidative stress result in atherosclerosis?

Answer 42

it causes endothelial dysfunction and thus reduced NO availability, which leads to lipid deposition, vasoconstriction, platelet aggregation, luekocyte adhesion, etc.

Question 43

What are some risk factors for atherosclerosis?

Answer 43

smoking, diabetes, aging, obesity, dyslipidemia, hypertension

Question 44

What is atheroscelerosis?

Answer 44

deposition of fatty material in the wall of the vessel to form a lesion

Question 45

Atheroscelerosis typically involves what sorts of blood vessels?

Answer 45

large arteries

Question 46

Atheromas are responsible for what health issues?

Answer 46

MI, cerebral infarction or stoke, and gangrene

Question 47

Atheromas in the peripheral vasculature can lead to what problem?

Answer 47

gangrene

Question 48

How do cells and macromolecules enter lymphatic capillaries?

Answer 48

muscular contractions open spaces between lymphatic endothelial cells which lack tight junctions

Question 49

What is vasculogenesis?

Answer 49

creation of a new vascular network

Question 50

What is angiogenesis?

Answer 50

sprouting of new vasculature from an existing network

Question 51

What is VEGF?

Answer 51

vascular endothelial growth factor, required for vasculogenesis and angiogenesis

Question 52

What are angiopoietins?

Answer 52

compounds required for vasculogenesis and angiogenesis

Question 53

What is the main regulator of hypoxia-induced angiogenesis and vasculogenesis?

Answer 53

HIF-1

Question 54

What is HIF-1?

Answer 54

a transcription factor that regulates hypoxia-induced angiogenesis

Question 55

What are the target genes of HIF-1?

Answer 55

EPO, VEGF, IGF2, and GLUT

Question 56

HIF-1 binds what element of DNA?

Answer 56

the hypoxia response element, HRE