BIOL 1117 Study Guide - Midterm Guide: Axon, Axon Hillock, Myelin
3 Oct 2017
School
Department
Course
Professor
Document Summary
Smooth muscle: has myocytes that have fusiform shape (1 nucleus! Has myocytes (electrically connected by gap junctions: allows cells to directly stimulate each other for contraction: smooth muscle contraction is involuntary (voluntary for skeletal) many diff. inputs can go to the plasma membrane (affects contractile ability) Inputs into smooth muscle can be nerves, hormones or local factors (increase or decrease contraction!) Can trigger and modify contractions of smooth muscle. Stimulate smooth muscle with either acetylcholine or norepinephrine. These neurotransmitters have contrasting effects in different locations. For example, norepinephrine (ne) can relax or constrict smooth muscle in different arteries depending on the neurotransmitter receptor types. While ne can relax smooth muscle in the bronchioles. Voltage, ligand, and mechanically-gated (responds to stretch) ca+2 channels. Calcium entry not sodium entry leads to depolarization of smooth muscle. During relaxation, calcium is pumped back out of the cell: calcium binds to calmodulin on thick filaments.
