vascular endothelium 2

Question 1

what are the stages of the pathogenesis of atherosclerosis?

Answer 1

• endothelial dysfunction in atherosclerosis
• fatty streak formation in atherosclerosis
• the formation of an advanced complicated lesion of atherosclerosis

Question 2

**explain what is happening in endothelial dysfunction?

Answer 2

**

Question 3

**explain what is happening in fatty streak formation in atherosclerosis ?

Answer 3

**

Question 4

**explain what is happening in the formation of an advanced complicated lesion of atherosclerosis?

Answer 4

**

Question 5

*what are the three layer of blood vessels

Answer 5

-tunica adventitia
nerves , vasa vasorum

-tunica media (smooth muscle)
external elastic membrane
smooth muscle

-tunica intima (endothelium cells) 
elastic membrane 
smooth muscle and connective tissue 
basement membrane
endothelium
*****

Question 6

what is a feature of blood vessels?

Answer 6

they are not all the same

Question 7

what do endothelial cells do?

Answer 7

• angiogenesis
• inflammation
• vascular tone and permeability
• angiogenesis
• thrombosis and haemostasis

Question 8

how does regulation of endothelial homeostasis take place?

Answer 8

• there is a resting endothelial
• however it can tip from one side to another
• in healthy state the endothelia tend to maintain an anti-thromabotic, anti inflammatory and anti proliferative state

Question 9

***what things might activate the endothelium leading to atherosclerosis?

Question 10

what is the normal leukocyte recruitment?

Answer 10

this normally takes place during inflammation

• leukocytes adhere to the endothelium of the post capillary venules and transmigrate into the tissues

Question 11

** what is the leukocyte recruitment in atherosclerosis?

Answer 11

• leukocytes adhere to activated endothelium of large arteries and get stuck in the sub endothelial space
• newly formed post capillary venules at the base of developing lesions provide further portals for leukocyte entry
• selectins which are not turned off dont have partners on the endothelium so they dont bind to it

Question 12

** what is rolling and activation?

Answer 12

at inflammation the endothelium becomes activated and expresses ligands for the leukocytes

• the selectins on the leukocyte begin to weakly interact with the endothelium
  this initiates rolling

Question 13

**what is firm adhesion?

Answer 13

• this is when internal signals activate the integrins on the surface of the leukocyte - so they are switched to high affinity
• the integrins then bind strongly to the endothelium
• the leukocyte adheres and transmigrates