1. SKELETAL MUSCLE STRUCTURE
LAB #19

3. Muscles Muscle - an organ comprised of: Skeletal MUSCLE tissue
CONNECTIVE tissue
NERVOUS tissue - contract
BLOOD - nourish

4. Connective Tissue Coverings
Layers of dense connective tissue (FASCIA) surround & separate each muscle.
Connective tissue extends beyond ends of muscle & gives rise to cord like TENDONS - fused to periosteum of bones.
Sometimes muscles are connected to each other by broad sheets of connective tissue – APONEUROSES.

5. Under outer layer another layer of connective tissue around each whole muscle – EPIMYSIUM.
PERIMYSIUM surrounds individual bundles of fibers - FASICICLES within each muscle.
Each muscle cell (fiber) covered by a connective tissue layer - ENDOMYSIUM.

6. SKELETAL MUSCLE (670x)

7. Skeletal Muscle Fibers Structure
Muscle fiber membrane – SARCOLEMMA contains cytoplasm – SARCOPLASM.
Within sarcoplasm are many perpendicular MYOFIBRILS composed of smaller filaments.
Myofilaments - 2 types of filaments
thicker filament - protein MYOSIN
thinner - protein ACTIN.
Dark stripes – A bands
Light bands - I bands.

8. T tubules = transverse tubules. Open to outside
SARCOMERES - unit extending from 1 Z-line to next (center of I band).
T tubules = transverse tubules.
Open to outside
Associated with SARCOPLASMIC RETICULUM.
Contains Ca+ ion.

12. Muscle Terminology Origin - immovable end of a muscle.
Insertion - movable end.
Prime mover (agonist) – main muscle moving
Synergists – assist prime mover
Antagonists – works opposite prime mover

13. http://glencoe. mheducation
hapter8/function_of_the_neuromuscular_junction_.html

14. http://glencoe. mheducation
hapter8/action_potentials_and_muscle_contraction.html

15. Figure 08.03

16. Figure 08.09a

19. 08.14