Green - Smooth Muscle Flashcards Preview

Structure And Function III > Green - Smooth Muscle > Flashcards

Flashcards in Green - Smooth Muscle Deck (12)
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1
Q

Calcium binding protein that activates MLCK

A

Calmodulin

2
Q

IP3

A

Formed from PIP2 by Phopholipase C

Signaling molecule in smooth muscle contraction and relaxation

3
Q

Found in tonic smooth muscle contractions where long-term tension is generated under conditions of low calcium and ATP concentrations

A

Latch State

4
Q

In multi-unit smooth muscle, the cells are not connected _____

A

Electrically

5
Q

Contractile fibers not arranged in sarcomeres

Contraction alters dimensions of organs

Contractions last much longer than in skeletal muscle

A

Smooth muscle

6
Q

Actin thin filaments in smooth muscle cells contain tropomyosin but no ?:

A

Troponin

7
Q

Myosin isoform is different in smooth muscle than that in skeletal muscle in that it has ?

A

Slower ATPase activity

8
Q

Sustained smooth muscle contraction requires what ?

A

Extracellular calcium

9
Q

Calcium enters the cell and binds to calmodulin. The calmodulin then activates _______ which phosphorylates regulatory light chains of myosin

A

Myosin light chain kinase

10
Q

Smooth muscle contraction is _____- regulated

A

Thick filament

(Skeletal muscle is thin filament regulated_

11
Q

Phasic contractions

A

Contracts rhythmically or intermittently

12
Q

Tonic contractions

A

Contracts continuously