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Lecture Human anatomy and physiology - Chapter 9: Muscles and muscle tissue (part a)

Chapter 9 - Muscles and muscle tissue (part a) provides knowledge of muscle tissues and skeletal muscle. The following will be discussed in this chapter: Types of muscle tissue, special characteristics of muscle tissue, muscle functions, gross anatomy of a skeletal muscle, microscopic anatomy of a skeletal muscle fiber, sliding filament model of contraction, physiology of skeletal muscle fibers,. | 9 Muscles and Muscle Tissue: Part A Three Types of Muscle Tissue Skeletal muscle tissue: Attached to bones and skin Striated Multi-nucleated Voluntary (i.e., conscious control) Powerful Three Types of Muscle Tissue Cardiac muscle tissue: Only in the heart Striated Single nucleated Involuntary Autorhythmic Three Types of Muscle Tissue Smooth muscle tissue: In the walls of hollow organs, e.g., stomach, urinary bladder, and airways Not striated Involuntary Single nucleated Table 9.3 Special Characteristics of Muscle Tissue Excitability (responsiveness or irritability): ability to receive and respond to stimuli Contractility: ability to shorten when stimulated Extensibility: ability to be stretched Elasticity: ability to recoil to resting length Muscle Functions Movement of bones or fluids (e.g., blood) Maintaining posture and body position Stabilizing joints Heat generation (especially skeletal muscle) Skeletal Muscle Each muscle is served by one artery, one nerve, and one or more veins Skeletal Muscle Connective tissue sheaths of skeletal muscle: Epimysium: dense regular connective tissue surrounding entire muscle Perimysium: fibrous connective tissue surrounding fascicles (groups of muscle fibers) Endomysium: fine areolar connective tissue surrounding each muscle fiber Figure 9.1 Bone Perimysium Endomysium (between individual muscle fibers) Muscle fiber Fascicle (wrapped by perimysium) Epimysium Tendon Epimysium Muscle fiber in middle of a fascicle Blood vessel Perimysium Endomysium Fascicle (a) (b) Skeletal Muscle: Attachments Muscles attach: Directly—epimysium of muscle is fused to the periosteum of bone or perichondrium of cartilage Indirectly—connective tissue wrappings extend beyond the muscle as a ropelike tendon or sheetlike aponeurosis Table 9.1 Microscopic Anatomy of a Skeletal Muscle Fiber Cylindrical cell, up to 30 cm long Multiple peripheral nuclei Many mitochondria Glycosomes for glycogen storage Myoglobin for O2 storage Also contain myofibrils, . | 9 Muscles and Muscle Tissue: Part A Three Types of Muscle Tissue Skeletal muscle tissue: Attached to bones and skin Striated Multi-nucleated Voluntary (i.e., conscious control) Powerful Three Types of Muscle Tissue Cardiac muscle tissue: Only in the heart Striated Single nucleated Involuntary Autorhythmic Three Types of Muscle Tissue Smooth muscle tissue: In the walls of hollow organs, e.g., stomach, urinary bladder, and airways Not striated Involuntary Single nucleated Table 9.3 Special Characteristics of Muscle Tissue Excitability (responsiveness or irritability): ability to receive and respond to stimuli Contractility: ability to shorten when stimulated Extensibility: ability to be stretched Elasticity: ability to recoil to resting length Muscle Functions Movement of bones or fluids (e.g., blood) Maintaining posture and body position Stabilizing joints Heat generation (especially skeletal muscle) Skeletal Muscle Each muscle is served by one artery, one nerve, and one or more veins