HTHSCI 1H06 Lecture Notes - Lecture 12: Autonomic Nervous System, Cardiac Muscle, Chemical Synapse

• School: McMaster University
• Department: Health Sciences
• Course: HTHSCI 1H06
• Professor: Alexander Ball

Document Summary

Lines the hollow tubes of the body". Ie: arteries, digestive system, respiratory, urinary and reproductive tracts. Contains thick (myosin) and thin (actin) laments but less organized than skeletal muscle. No striations : laments are anchored to dense bodies on the intermediate lament network (in the cytosol) Hormones, stretching, other local factors (nitric oxide) Cells are stimulated individually, usually by ans (ie: large airways, large arteries, iris, arrector pili) Gap junctions link cells which function together. Stimulated by ans, hormones, or pacemaker cells and can often be induced by stretching (ie: uterus, urinary bladder, gi tract, small arteries) Cardiomyocytes (cardiac muscle cells) have 1-2 nuclei that are branched". Intercalated discs (icds) are specialized areas where cardiomyocytes connect. Gap junctions allow direct communication between adjacent cells (permit the passage of ions) Action potentials (aps) spread rapidly through the cardiac conduction system (~1% of the cells in the heart are dedicated to this system)