Skeletal Muscles Histology fascicle Whole muscle Muscle fiber

Skeletal Muscles

Histology fascicle Whole muscle • ___________________ Muscle fiber myofibrils __________________

Histology • The three connective tissue layers of the muscle are: 1. epimysium 2. perimysium 3. endomysium • The _______ surrounds the whole muscle. • The _______ surrounds the fascicles. endomysium • The _______ surrounds the muscle fiber.

Histology • All three connective tissue layers come together at the tendon _______ to connect the muscle to the periosteum ________ of the bone. movement • The tendon allows _______ of the bone due to contraction the ________ of the muscle. Concept Check • What happens if the tendon is severed?

Histology Terminology of the Skeletal Muscle Cell vs. Typical Body Cell Skeletal Muscle Cell Typical Body Cell Muscle Fiber Cell Sarcolemma Cell Membrane Sarcoplasm Cytoplasm Sarcoplasmic Reticulum Smooth ER

Histology Overview of Organization • • organ The whole muscle is an _______. The fascicle is a _________. bundle of muscle fibers cell The muscle fiber is a ___________. myofibrils Inside the muscle fibers are ________.

Histology Inside the muscle fiber Transverse tubules SR_____, Sarcoplasm • ___________, network ________ • Transverse tubules form a _______ of tubules throughout the muscle fiber. • Why are these tubules necessary? Allow electrical impulses to be sent through the muscle fiber to coordinate contractions

Histology Myofibrils muscle fiber • _______ exist inside the ______. 100’s 1000’s • One muscle fiber contains ______ to _____ myofilaments of myofibrils. • Inside myofibrils are _________.

Histology thin filaments and • The two types of myofilaments are ________, filaments ______thick _______. Muscle fiber • They are responsible for ______ contractions _______.

Histology • Myofilaments are composed of repeating functional units sarcomeres_____-tocalled _________, arranged end ______. sarcomere-sarcomere-sarcomere functional • The sarcomere is the smallest ______ unit of the muscle fiber.

Histology border • Z line is the _______ of the sarcomere. middle • M line is the _____ of the sarcomere. It attaches filament to its the central portion of the ____thick _____ neighbors. dark • A band is _______ because the area contains thick ____filaments _____. light • I band is ____ because the area contains thin filaments ________. • H zone has only thick filament ____________

Histology • Putting it all together http: //www. youtube. com/watch? v=Xo. P 1 dia. XVCI