Smooth muscle Flashcards
Smooth muscles have mechanoreceptors called _
Caveolae
_ junctions connect smooth muscles
Gap
Types of smooth muscle(2)
- Single unit myogenic
- Multiunit neurogenic
Where do we find myogenic smooth muscle?
High or low innervation rate?
Act as unit or independent?
Respond to stretch?
- Uterus, GI, bladder, vessels
- Low
- Act as a unit(gap)
- Yes
Where do we find neurogenic smooth muscle?
High or low innervation rate?
Act as unit or independent?
Respond to stretch?
- Ciliary bodies, eye sphincters, vas deferens, resp tract, large arteries
- High
- Independent(precise control)
- No
Stretch due to food bolus causes _ which leads to _
- AP, spike potentials
More spikes > _, _ contraction
- Longer, stronger
Phasic contraction:
Muscles normally _
Occurs in _
- Relaxed
- GI, esophagus, stomach, bladder
Tonic contraction:
Muscles normally _
Occurs in _
Phenomenon?
- Contracted
- Sphincters, vessels
- Latch
T/F: Same amount of myosin and actin in smooth and skeletal muscle
False, less myosin, more actin
Myosin has a _ ATPase activity > _ contraction
- Lower, slower
Ca2+ enters via?
Sarcolemma
Process of cross-bridge(start from Ca2+)
Ca2+ enters cell > binds calmodulin > MLCK > increases ATPase activity > contraction
Relaxation mechanism(2)
- Decrease Ca2+
- Myosin phosphatase
Relaxation mechanism(2)
- Decrease Ca2+
- Myosin phosphatase
