Smooth Muscle Flashcards
Are smooth muscle cells mono or multinucleated?
Mono
What are the 2 primary functions of smooth muscle cell to cell junctions?
Mechanical Coupling
Ionic Coupling
What type of junctions provide mechanical coupling?
Intermediate Junctions
What protein does smooth muscle lack compared to skeletal muscle?
troponin
What 2 unique proteins does it have that skeletal muscle does not?
Calponin
Caldesmon
What are the two classes of smooth muscle based on how the muscle is stimulated to contract?
Multiunit Smooth Muscle
Single Unit
What is unique about the smooth muscle SR?
IP3 Receptors
Ryanodine Receptors
Ca2+ Pumps
Which group of smooth muscle is neurogenic?
Multi-unit
What are the excitatory transmitters of smooth muscle?
ACh
Substance P
Norepinephrine
What are the inhibitory Transmitters?
Vasoactive Intestinal Peptide
Nitric Oxide
Besides neurotransmitters, how else can smooth muscle contractions be regulated?
Hormones
Local metabolites
Stretch
What serves as the pacemaker for smooth muscle “slow wave” contractions?
ICC Interstitial Cells of Cajal
