Smooth Muscle physiology Flashcards Preview

S&F III: Exam 1 > Smooth Muscle physiology > Flashcards

Flashcards in Smooth Muscle physiology Deck (16):
1

Unitary Type

lg sheets connected by gap junctions that have waves of contraction (contract as one unit)

2

multi-unit

no electric connection, individual stimulation

3

actin structure

NO troponin; just tropomyosin

4

myosin structure

slow ATP-ase activity

5

Actin-Myosin Structure

long filaments on periph of cell, inc ratio

6

SR structure

No t-tubules!

7

tonic contraction

prolonged

8

phasic contraction

cyclic

9

Length-Tension

varies over hours, "L-adaptation"

*changes in contractile unit #s*

10

Force-Velocity

depends on load
Velocity Slower, affected by phosphor of MLC
**reg by: x-bridge rate and # of bridges**

11

Intestinal ANS effect

PNS: +mem. potential, +contraction
SNS: - mem potential, + relaxation

12

Lungs ANS

PNS: + contraction
SNS: +B-adrenergic, +relaxation

13

Blood Vessel ANS

SNS: +A-adrenergic, +constriction

14

Relaxation Regulation

- Ca Channels, + K channels

+cGMP, - kinases, +MLCP

+cAMP, +B-and, -MLCK, -MLC, -contract

15

what happens in relaxation?

SERCA activated, MLCP dephosph MLC

16

what happens in contraction

IP3 and volt channels increase IC Ca
Ca-calmodulin act. MLCK which act. MLC