1. Muscles & Muscular Tissues 12 Feb. 2013Musc-tissue-lab.ppt1

2. 12 Feb. 2013Musc-tissue-lab.ppt2 MUSCLE TISSUE Abundant, dense tissue –40-50% of body weight High metabolic activity –high energy use/output; –O 2 consumption; –CO 2 production

3. 12 Feb. 2013Musc-tissue-lab.ppt3 Characteristics of Muscle Tissue Contractility –Muscle tissue shortens producing force. –“Muscles can only contract!” Excitability –Responds to nerve impulses by contracting. Extensibility –Can be stretched by outside force (such as by another muscle). Elasticity –Recoils after being stretched

4. 12 Feb. 2013Musc-tissue-lab.ppt4 Functions of Muscle Tissue Produce movement by contracting –Locomotion & manipulation –Movement of blood, food, urine, etc. through hollow organs Maintenance of posture Stabilize joints –so that other muscles can produce movement or maintain posture Heat production –Maintenance of body temperature.

5. 12 Feb. 2013Musc-tissue-lab.ppt5 Gross structure of a skeletal muscle: Tendons connect muscle to bone, transmit force. Origin = attachment to more stationary (proximal) bone Insertion = attachment to more mobile (distal) bone Belly = muscular tissue Head = one of multiple origins (-ceps)

6. 12 Feb. 2013Musc-tissue-lab.ppt6 Naming of muscles Shape, arrangement of fibers –Deltoid, orbicularis oris Location, origins/insertions –Pectoralis major Size –Latissimus dorsi Action –Flexor carpi ulnaris

7. 12 Feb. 2013Musc-tissue-lab.ppt7 Muscle Groups Agonist (prime mover) vs. Antagonist  Muscles can only CONTRACT !!  Muscle must be stretched by antagonist(s) before it can contract again. Synergist(s) = muscle(s) that works with prime mover. Fixator(s) = muscle(s) that stabilizes body part. –Prevents one kind of motion so another can happen.

8. 12 Feb. 2013Musc-tissue-lab.ppt8 Three Kinds of Muscle Tissue Skeletal muscle: –Striated, usu. voluntary, attached to skeleton Cardiac muscle: –Striated, involuntary, walls of heart Smooth muscle: –Non-striated, involuntary, wrapping of hollow organs –Stomach, intestines, arteries, bladder, vas deferens, uterus, etc.

9. 12 Feb. 2013Musc-tissue-lab.ppt9 Skeletal Muscle: Long, cylindrical cells, Multinucleate (nuclei peripheral), Covered by plasma membrane (sarcolemma), Striated.

10. 12 Feb. 2013Musc-tissue-lab.ppt10 Cardiac Muscle Branched cells Striated Intercalated discs

11. 12 Feb. 2013Musc-tissue-lab.ppt11 Smooth Muscle Non-striated Thin cells pointed at ends wrapping of hollow organs