Lecture 31

Question 1

Which type of vessels are most vulnerable to compression, occlusion, neoplastic invasion, and bystander injury by extension of inflammation from adjacent tissues?(2)

Answer 1

veins and lymphatics

Question 2

How is the inner half of the wall of a blood vessel supplied with O2 and nutrients
-outer half?

Answer 2

the inner part is avascular and relies on diffusion from the vessel lumen
-vasa vasorum

Question 3

how do VSM cells respond to sustained inc in blood vol or pressure?

Answer 3

by undergoing hypertrophy and (lesser) hyperplasia

Question 4

Myointimal cells

Answer 4

smooth myocytes stimulated by growth factors they migrate through pores in the internal elastic lamina into the subendothelial layer (will synthesize and deposit collagen and elastin fibers here)

Question 5

what causes hypertrophy of SMC of arterioles? Possible consequences?

Answer 5

response to sustained hypertension or hyperperfusion

could dec vessel lumen and inc vascular resistance

Question 6

When does sustained arteriolar vasoconstriction occur? Consequences?

Answer 6

systemic hypertension->vasoconstriction->exacerbation of hypertension->downstream ischemic tissue injury(ex frostbite)

Question 7

Arteriosclerosis

Answer 7

hardening of the arteries-chronic degenerative disease, loss of elasticity

Question 8

Atherosclerosis

Answer 8

arteriosclerosis in which there is significant lipid deposition and fatty degeneration of vessel wall

Question 9

what does arteriosclerosis look like grossly

Answer 9

lesions may or may not be grossly obvious

slightly raised, thickened wrinkled intima or flat white oval or linear plaques

Question 10

Clinical significance of arteriosclerosis

Answer 10

rarely of clinical significance

advanced lesions predispose to thrombosis

Question 11

characteristic lesions of athersclerosis

Answer 11

atheroma (fibrofatty plaque)- focal raised intima of plaque with lipid core covered by fibrous cap

Question 12

circumstances atherosclerosis likely to develop? (species) clinical significance?

Answer 12

rabbits, chickens, and pigs
pigs are common- high fat diets (do not cause thrombosis in pigs)
clinically significant atherosclerosis is rare

Question 13

arteriolosclerosis

Answer 13

non fatty degeneration of arterioles of small to medium size

Question 14

Hyaline degeneration

Answer 14

spectrum of arteriolosclerotic lesions involving depsotion of collagen, elastin, glycosaminoglycans or amyloid in the tunica intima

Question 15

Fibrinoid change

Answer 15

extracellular degenerative change in damaged small arteries and arterioles (injury to vascular endothelium)

Question 16

when can arterial mineralization develop? gross features?

Answer 16

dystrophic (necrotic tissue)-vasculitis, arteriosclerosis, thrombosis
metastatic (inc serum Ca [ ])- vit D toxicity
raised or flat white gritty plaques in intima or aorta, pulmonary artery

Question 17

Arterial rupture causes apart from trauma

Answer 17

spontaneous
horses- infection of guttral pouch (internal carotid)
aged mares at partuition (uterine)

Question 18

aneurysm

Answer 18

localized abnormal outpouching of blood vessel

Question 19

dissecting aneurysm

Answer 19

blood enters vessel wall and dissects between two layers of tunica media to create cavity within the vessel wall

Question 20

vasculitis

Answer 20

inflammation of vessels

Question 21

arteritis

Answer 21

inflammation of arteries

Question 22

phlebitis

Answer 22

inflammation of vein

Question 23

lymphangitis

Answer 23

inflammation of lymphatics

Question 24

Some causes of vasculitis

Answer 24

develop from within the vessel lumen- endothelial damage by infectious agents

Question 25

potential consequences of vasculitis

Answer 25

depend on size and type of vessel, degree of associated thrombosis hemorrhage and edema

Question 26

Verminous arteritis | 2 causes

Answer 26

caused by parasites (strongylus vulgaris larvae- root of mesenteric artery in horses) heartworm

Question 27

steroid responsive meningeal arteritis

Answer 27

polyarteritis thought to be immune mediated- severe necrotising arteritis

Question 28

thrombophlebitis

Answer 28

phlebitis invariably leads to thrombosis

Question 29

common cause of jugular thrombophlebitis(3)

Answer 29

inept or repeated venipunture injection of irritant solutions indwelling catheters

Question 30

Bacterial agents that commonly cause lymphangitis...

Answer 30

anthrax | tuberculosis

Question 31

Phlebectasia

Answer 31

dilation of a vein (varicosity)

Question 32

Usual cause of lymphedema? difference between primary and secondary

Answer 32

swelling of tissue due to impaired drainage -primary- abnormal development secondary-obstruction of previously normal lymphatics (inflammation, neoplasia, trauma)

Question 33

Intestinal lymphangiectasia

Answer 33

dilation of intestinal lymphatics | common cause of PLE in dogs

Question 34

chylothorax

Answer 34

free chylomicron rich lymph within the thoracic cavity

Question 35

2 most common neoplasms arising from vascular endothelium

Answer 35

hemangioma (benign) | hemangiosarcoma (malignant)