14 terms

Chapter 9 - Smooth Muscle

The alternating contraction and relaxation of these opposing layers mixes substances in the lumen and squeezes them through the organ's internal pathway
The numerous bulbous swelling sof the nervous system in conjunction with the smooth muscle
Diffuse Junction
Junctions where the varicosities release neurotranmitter into a wide synaptic cleft in the general area of the smooth muscle cell
Pouchlike infoldings that sequester bits of extracellular fluid containing a high concentration of Ca2+ close to the membrane
Dense Bodies
Places where at regular intervals to cytoplasmic structures, smooth muscle fibers contain a lattice like arrangement of not contractile intermediate filaments that resist tension
A cytoplasmic calcium binding protein, it is a regulatory molecule
myosin kinase
A kinase enzyme that phosphorylates the myosin, activating it.
nerves, hormones, local chemical changes
What are the three factors of smooth muscle regulation?
stretch, length and tension change, hyperplasia
What are the three special characteristics of smooth muscle?
Stress Relaxation Response
It allows a hollow organ to fill or expand slowly to accommodate a greater volume without promoting strong contractions that would expel its contens
When muscle fibers can divide to increase their numbers
Single unit smooth muscle
Smooth muscle found in the walls of all hollow organs except the heart.
Multiunit Smooth Muscle
Smooth muscle found in the large airways to the lungs and in large arteries, the arrector pili muscles, internal eye muscles
immature muscle cells, form muscle cells