Muscles

1. Muscles

2. Roots To Know • Calat – something inserted • Erg – energy • Hyper – excess • Laten – hidden • Myo – muscle • Sarco – flesh • Syn – together • Tetan – stiff • Troph – well fed

3. Functions of Muscle Tissue • Movement • Stabilize body positions • Regulate organ volume • Sphincter – closes off the exterior outlets of hollow organs – controls the size of an opening • Urinary bladder • Move substances within the body • Produce heat

4. Characteristics of Muscle Tissue • Excitability/Responsiveness – the ability to receive and respond to stimuli • Contractility – the ability to shorten/contract • Elasticity-- the ability to return to its original shape after contraction or extension • Extensibility -- the ability to stretch or extend

5. Types of Muscle Tissue • Skeletal • Cardiac • Smooth These sound really familiar—where can each be found????

6. Skeletal Muscle Tissue • Composed of cells called Muscle Fibers • Muscle Fiber • Mitochondrion – many in one fiber – Why? • Sarcolemma – plasma membrane, stores Ca2+ • Sarcoplasm – equivalent of cytoplasm • Muscle – group of muscle fibers bundled together

7. Cardiac Muscle • Muscle fibers are connected by intercalated discs • Normal heart beat ~75 beats/minute • Requires a steady supply of oxygen and nutrients • Cells contain more mitochondria than skeletal muscle fibers

8. Smooth Muscle Tissue • Prolonged presence of Ca2+ provides the smooth muscle tone – state of continued partial contraction • Stretchiness – stomach, bladder, uterus