80 likes | 270 Views
Chapter 11 Muscle. Conwin Vanterpool, Ph.D. Muscle Tissue. Composed of cells that contract when stimulated Helps move the body and specific body parts Skeletal, cardiac, smooth. Skeletal Muscle. Located in muscles that attach to bones Long, cylindrical cells are striated
E N D
Chapter 11Muscle Conwin Vanterpool, Ph.D
Muscle Tissue • Composed of cells that contract when stimulated • Helps move the body and specific body parts • Skeletal, cardiac, smooth
Skeletal Muscle • Located in muscles that attach to bones • Long, cylindrical cells are striated • Cells are bundled closely together in parallel arrays Figure 33.9a, page 564
Smooth Muscle • In walls of many internal organs and some blood vessels • Cells are not striped and taper at the ends Figure 33.9c, page 564
Cardiac Muscle • Present only in the heart • Cells are striated and branching • Ends of cells are joined by communication junctions Figure 33.9b, page 564
nucleus TYPE: Skeletal muscle DESCRIPTION: Bundles of cylindrical, long, striated contractile cells; many mitochondria; often reflex-activated but can be consciously controlled LOCATIONS: Partner of skeletal bones, against which it exerts great force FUNCTION: Locomotion, posture; head, limb movements Fig. 33-9a2, p.564
adjoining ends of abutting cells TYPE: Cardiac muscle DESCRIPTION: Unevenly striated, fused-together cylindrical cells that contract as a unit owing to signals at gap junctions between them LOCATIONS: Heart wall FUNCTION: Pump blood forcefully through circulatory system Fig. 33-9b, p.564
nucleus TYPE: Smooth muscle DESCRIPTION: Contractile cells tapered at both ends; not striated LOCATIONS: Wall of arteries, sphincters, stomach, intestines, urinary bladder, many other soft internal organs FUNCTION: Controlled constriction; motility (as in gut); arterial blood flow Fig. 33-9c, p.564