Smooth Muscle

Question 1

What’s an autocoid?

Answer 1

Bio substance that acts like hormones to produce local response
Ie NO, angiotensin

Question 2

How is vasoconstriction caused in sm?

Answer 2

Have to increase ca release from inside cell via DAG/IP3 system, you also have to allow ca in via voltage and stretch channels

Question 3

How is vasodilation caused in sm?

Answer 3

1- actively start relaxing muscle
2- stop ca entering and make whatever ca is inside cells to be uptook via SRCA2ATPase
You block ca channels via hyperpolariation of membrane

Ca desensitisation

Question 4

How is sm cross bridge formed?

Answer 4

Myosin light chain and calmodulin bond to form an active complex

Question 5

What’s the electrical activity in sm?

Answer 5

Slow waves because of interstitial cells of cajal

Ap triggered because fo depolarisation

Question 6

What are the 2 types of SM?

Answer 6

Unitary - gi, airway

Non unitary- fine control, iris, piloerector