MUSCULAR SYSTEM NOTES MUSCULAR SYSTEM Muscles are responsible
MUSCULAR SYSTEM NOTES
MUSCULAR SYSTEM • Muscles are responsible for all types of body movement • Three muscle types: – Skeletal muscle – Cardiac muscle – Smooth muscle
TYPES OF MUSCLE TISSUE • SKELETAL – Most are attached by tendons to bones – Cells are multinucleated (more than one nuclei) – Striated – have visible banding – Voluntary – subject to conscious control
• SMOOTH – Has no striations – Spindle-shaped cells – Single nucleus – Involuntary – Found mainly in walls of hollow organs
• CARDIAC – Has striations – Usually has a single nucleus – Joined to another muscle cell at an intercalated disc – Involuntary
FUNCTION OF MUSCLE • Motion – change in body position • Movement of substances within body • Stabilizing body position and regulating organ volume • Thermogenesis (heat production)
CHARATERISTICS OF MUSCLE • Irritability – ability of muscles and nerves to respond to stimulus by producing electrical signals or action potentials • Contractility – ability to shorten when an adequate stimulus is received
CT COVERING OF MUSCLE • Endomysium – around single muscle fiber = muscle cell • Perimysium – around a fascicle • Epimysium – covers the entire skeletal muscle
• Three layers come together to form tendons • Tendons – attach muscle to periosteum of bones
• Aponeurosis – broad band of CT which form a flat layer of tendon • Fascia (“bandage”) – sheet or band of fibrous C. T. under the skin or around organs
- Slides: 15