Muscles Muscle Overview The three types of muscle

Muscles

Muscle Overview • The three types of muscle tissue are skeletal, cardiac, and smooth • These types differ in structure, location, function, and means of activation PLAY Inter. Active Physiology ®: Anatomy Review: Skeletal Muscle Tissue, page 3

Muscle Images

Sarcomere surrounded by sarcoplasmic reticulum

• sarcomere contraction • animation myofilament contraction__ • sliding-filament-theory

Sliding Filament Theory • Order the following events in sequence to explain the contraction of skeletal muscle. • ____ Ca+2 binds to troponin/tropomyosin (regulatory proteins) which opens myosin binding sites on actin. • ____ As ADP and P leave the myosin head, it swivels forward pulling the actin filament toward the center of the sarcomere. The sarcomere shortens. • ____ An action potential moving through the sarcolemma (what is this? ) stimulates release of Ca+2 from the sarcoplasmic reticulum. (what is this? ) • ____ Myosin heads (activated by the breakdown of ATP) bind to exposed sites on the actin filament. • ____ ATP binds to the myosin head and it relaxes, falling away from the actin filament. • _____ Cycle repeats until Ca 2+ or ATP are withdrawn.

Events at Neuromuscular Junction

Events at Neuromuscular Junction 1. 2. 3. 4. 5. 6. Action potential in the nerve is activated Ca 2+ runs into the nerve Ach is released into the synaptic cleft Ach binds to receptors on the muscle Na runs into the muscle Action potential runs across the muscle and into the T tubules 7. Enzymes break Ach into Acetic Acid and Choline

• Anatomy and Physiology • How a muscle contracts - Neuromuscular Junction/Sliding Filament Theory • • View the following websites to consolidate your understanding of the events at the neuromuscular junction and the sliding filament theory of muscle contraction. • : • http: //www. blackwellpublishing. com/matthews/nmj. html • http: //highered. mcgrawhill. com/sites/0072495855/student_view 0/chapter 10/animation__ function_of_the_neuromuscular_junction__quiz_3_. html • http: //bcs. whfreeman. com/thelifewire/content/chp 44/4403 s. swf • http: //media. pearsoncmg. com/bc/bc_0 media_ap/apflix/ap/ap_vid eo_player. html? tnj •

Do Now – Muscle #1 • Describe the structure and function of the three types of muscle tissue. • Draw sarcomere from a skeletal muscle cellshow the arrangement of the thin and thick filaments and label the sections of the sarcomere.

Muscle Contraction • View the following websites to consolidate your understanding of the events at the neuromuscular junction and the sliding filament theory of muscle contraction. • Neuromuscular junction: • http: //media. pearsoncmg. com/bc/bc_0 media_ap/apflix/ap/ap_vid eo_player. html? tnj • http: //www. blackwellpublishing. com/matthews/nmj. html • http: //highered. mcgrawhill. com/sites/0072495855/student_view 0/chapter 10/animation_f unction_of_the_neuromuscular_junction__quiz_3_. html • Inside the muscle fiber: • www. blackwellpublishing. com/matthews/myosin. html • http: //bcs. whfreeman. com/thelifewire/content/chp 47/4702001. ht ml