Lecture33: Local Reg Of Blood Flow

Question 1

What are vasoactive substances?

Answer 1

They are secreted from the endothelium, they are either vaso constrictors or dilators

Question 2

What are the vasoconstrictors?

Answer 2

TxA2 and Prostaglandin H2 and endothelins

Question 3

What do Vasoactive substances do?

Answer 3

They decrease calcium thus causing vasodilation

Question 4

What is NO’s half life?

Answer 4

6 seconds

Question 5

What are the target vessels for vasoactive substances?

Answer 5

Capacitance vessels and Arterioles

Question 6

Which endothelin receptor acts on smooth ms?

Answer 6

ET-A

Question 7

What endothelin receptor acts on endothelial cell?

Answer 7

ET-B

Question 8

What inhibits platelet aggregation?

Answer 8

Prostacyclins

Question 9

What does EDHF do?

Answer 9

They open k+ channels

Question 10

How does PGI2 vasodilate?

Answer 10

Increases cyclic AMP production thus activating PKA( Protein kinase A)

Question 11

What is the major sites of metabolic control?

Answer 11

Small Arterioles and precapillary sphincters

Question 12

What is the first step of vasodilation?

Answer 12

NO increases cGMP

Question 13

What is the second step of vasodilation?

Answer 13

Protein kinase opens potassium channels

Question 14

What is the 3rd step of vasodilation?

Answer 14

Calcium channels close