Robbins pg. 327-330; 357-363

Question 1

Vascular disease develops through what two principal mechanisms?

Answer 1

Narrowing or complete obstruction of vessel lumina, occurring either progressively (e.g., by atherosclerosis) or
acutely (e.g., by thrombosis or embolism)

Weakening of vessel walls, causing dilation and/or rupture

Question 2

T or F. As arteries narrow to arterioles, the ratio of wall thickness to lumen diameter increases

Answer 2

T, to allow more precise regulation of intravascular pressures.

Question 3

Where does atherosclerosis occur mainly?

Answer 3

in larger, muscular arteries

Question 4

Where does HTN occur mainly?

Answer 4

small arterioles

Question 5

What are the large elastic arteries?

Answer 5

aorta, arch vessels, iliac and pulmonary arteries

Question 6

Describe the structure of large arteries.

Answer 6

In these vessels, elastic fibers alternate with smooth muscle cells throughout the media, which expands during systole (storing some of the energy of each cardiac contraction), and recoils during diastole to propel blood distally

Question 7

What are the medium sized muscular arteries?

Answer 7

coronary and renal arteries

Question 8

Describe the structure of medium sized muscular arteries?

Answer 8

The media is composed primarily of smooth muscle cells, with elastin limited to the internal and external elastic lamina. The medial smooth muscle cells are circularly or spirally arranged around the lumen, and regional blood flow is regulated by smooth muscle cell contraction (vaso-
constriction) and relaxation (vasodilation) controlled by the autonomic nervous system and local metabolic factors (e.g., acidosis).

Question 9

T or F. Arterioles are where blood flow resistance is regulated.

Answer 9

T.

Question 10

How is blood flow regulated in arterioles?

Answer 10

As pressures drop during passage through arterioles, the velocity of blood flow is sharply reduced, and flow becomes steady rather than pulsatile.

Question 11

How big are capillaries?

Answer 11

About the size of a single red blood cells

Question 12

What organs have the highest capillary density?

Answer 12

metabolic organs like the heart

Question 13

Edema and leukocyte emigration characteristic of inflammation occurs preferentially where?

Answer 13

in postcapillary venules

Question 14

Compared to arteries at the same level of branching, how do veins compare? Consequence?

Answer 14

• larger diameter
• larger lumina
• thinner walls

Thus, veins are more prone to dilation, external compression, and penetration by tumors or inflammatory processes.

Question 15

Are endothelial cells similar throughout the body?

Answer 15

Although endothelial cells throughout the vasculature
share many attributes, they also show phenotypic variability
depending on the anatomic site and adaptations to local
environmental cues.

Question 16

What is endothelial activation?

Answer 16

endothelial cells respond to various physiologic and pathologic stimuli by modulating their usual (constitutive) functions and by expressing new (inducible) properties

Question 17

What are some endothelial inducers?

Answer 17

• bacterial/viral products
• cytokines
• hemodynamic stress
• lipid products
• hypoxia

Question 18

What happens when endothelial cells are activated?

Answer 18

• undergo shape changes,
• express adhesion molecules, and
• produce cytokines, chemokines, growth factors, pro- and anticoagulant factors,

and a host of other biologically active products—all presumably intended to respond to the original stimulus.

Question 19

The migratory and proliferative activities of smooth muscle cells are regulated by what?

Answer 19

• PDGF
• endothelin
• thrombin
• fibroblast growth factors, and
• inflammatory mediators such as IFN-γ and IL-1.

Question 20

Factors that maintain smooth muscle cells in a quiescent state include:

Answer 20

heparan sulfate, NO, and TGF-α

Question 21

What are three important congenital vascular anomalies?

Answer 21

• Berry aneurysms
• Arteriovenous (AV) fistulas
• Fibromuscular dysplasia

Question 22

What are Berry aneurysms?

Answer 22

thin-walled arterial outpouchings in cerebral vessels, classically at branch points around the circle of Willis;

they occur where the arterial media is congenitally attenuated and can spontaneously rupture causing fatal intracerebral hemorrhage

Question 23

What are AV fistulas?

Answer 23

abnormal connections between arteries and veins without an intervening capillary bed.

Question 24

What is Fibromuscular dysplasia?

Answer 24

a focal irregular thickening of the walls of medium-sized and large muscular arteries due to a combination of medial and intimal hyperplasia and fibrosis.

The focal wall thickening results in luminal stenosis or can be associated with abnormal vessel spasm that reduces vascular flow

Question 25

When does fibromuscular dysplasia occur?

Answer 25

It can manifest at any age but occurs most frequently in young women.

Question 26

What are some rules of thumb for distinguishing between benign hemangiomas and malignant angiosarcomas?

Answer 26

• Benign tumors usually contain obvious vascular channels
filled with blood cells or lymph that are lined by a monolayer of normal-appearing endothelial cells.

• Malignant tumors are more cellular, show cytologic atypia, are proliferative, and usually do not form well organized vessels`

Question 27

What is Ectasia? Telangiectasia?

Answer 27

generic term for any local dilation of a structure

Telangiectasia is used to describe a permanent dilation of preexisting small vessels (capillaries, venules, and arterioles, usually in the skin or mucous membranes) that forms a discrete red lesion.

These lesions can be congenital or acquired and are not true neoplasms.

Question 28

What is nevus flammeus?

Answer 28

(a “birthmark”), the most common form of vascular ectasia, is a light pink to deep purple flat lesion on the head or neck composed of dilated vessels.

Most ultimately regress spontaneously.

Question 29

When are spider telangiestasias most common? Association?

Answer 29

• face, neck, or upper chest

- frequently are associated with hyperestrogenic states (e.g., in pregnant women or patients with cirrhosis).

Question 30

What is Hereditary hemorrhagic telangiectasia?

Answer 30

(Osler-Weber-Rendu disease) is an AD disorder caused by mutations in genes that encode components of the TGF-β signaling pathway in endothelial cells.

The telangiectasias are malformations composed of dilated capillaries and veins that are present at birth.

The lesions can spontaneously rupture, causing serious epistaxis (nosebleed), gastrointestinal bleeding, or hematuria.

Question 31

T or F. Most hemangiomas regress spontaneously

Answer 31

T.

Question 32

While hemangiomas typically are localized lesions confined to the head and neck, they occasionally may be more extensive. What is this called?

Answer 32

Angiomatosis- can arise internally. Nearly one third of these internal lesions are found in the liver

Malignant transformation is rare

Question 33

What are some types of hemangiomas?

Answer 33

• capillary hemangiomas
• juvenile hemangiomas
• pyogenic granulomas
• cavernous hemangiomas

Question 34

Describe juvenile hemagiomas.

Answer 34

Aka strawberry hemangiomas of the newborn skin are extremely common (1 in 200 births) and can be multiple.

These grow rapidly for a few months but then fade by the age of 1 to 3 years, with complete regression by age 7 in the vast majority of cases.

Question 35

Describe cavernous hemangiomas.

Answer 35

composed of large, dilated vascular channels.

Compared with capillary hemangiomas, cavernous hemangiomas are more infiltrative, frequently
involve deep structures, and do not spontaneously
regress.

Question 36

Are cavernous hemangiomas prognostically bad?

Answer 36

They may be locally destructive, so surgical excision may be required in some cases. More often the tumors
are of little clinical significance, but they can be cosmetically troublesome and are vulnerable to traumatic ulceration and bleeding.

Brain hemangiomas also are problematic, as they can cause symptoms related to compression of adjacent tissue or rupture.

Question 37

What are glomus tumors?

Answer 37

benign, exquisitely painful tumors arising from specialized smooth muscle cells of glomus bodies, arteriovenous structures involved in thermoregulation.

Question 38

How are glomus tumors different from cavernous hemangiomas?

Answer 38

Glomangiomas arise from smooth muscle cells, rather than endothelial cells. They most commonly are found in the distal portion of the digits, especially under the fingernails.

Excision is curative

Question 39

What is Bacillary angiomatosis caused by?

Answer 39

a vascular proliferation in immunocompromised hosts (e.g., patients with AIDS) caused by opportunistic gram-negative bacilli of the Bartonella family

Question 40

What species of Bartonella are responsible for Bacillary angiomatosis?

Answer 40

Bartonella henselae, whose principal reservoir is the domestic cat; this organism causes cat-scratch disease (a
necrotizing granulomatous disorder of lymph nodes) in
immunocompetent hosts.

Bartonella quintana, which is transmitted by human body lice; this microbe was the cause of “trench fever” in
World War I.

Question 41

How do Bartonella cause Bacillary angiomatosis?

Answer 41

The bacteria induce host tissues to produce hypoxia-inducible factor-1α (HIF-1α), which drives VEGF production and vascular proliferation.

Question 42

Treatment for Bacillary angiomatosis?

Answer 42

The infections (and lesions) are cured by antibiotic
treatment