Presentation on theme: "Study guide… What are the three types of muscle tissue, their structure and location? What are the functions of the muscular system? How are skeletal muscles."— Presentation transcript:
1 Study guide…What are the three types of muscle tissue, their structure and location?What are the functions of the muscular system?How are skeletal muscles and muscle fibers structured from largest to smallest?What are the steps of skeletal muscle contraction?How do skeletal muscle cells acquire ATP for contraction?Distinguish between slow and fast twitch fibers.What are some common muscular disorders?
9 The sarcomere Made of protein myofilaments Thick: myosin Thin: actin, troponin, tropomyosinThese filaments slide over one another during muscle contraction
10 The beginning of muscle contraction: The sliding filament model 1. What type of neuron carries information toward the muscle?2. What is released from the pre-synaptic cell?3. What does it bind to? (This binding will cause calcium to be released from the SR.)
12 Muscle contraction continued… 4. Released calcium combines with troponin5. Myosin binding sites exposed6. Cross-bridges form7. ATP binds and power stroke occurs
13 Visualizing the role of calcium and myosin in muscle contraction
14 What are the sources of ATP for muscle contraction? Limited amounts of ATP are stored in muscle fibersCreatine phosphate pathway (CP) – fastest way to acquire ATP but only sustains a cell for seconds; builds up when a muscle is restingFermentation – fast-acting but results in lactate build upCellular respiration (aerobic) – not an immediate source of ATP but the best long term source
15 Muscle fibers come in two forms Fast-twitch fibers:rely on CP and fermentation (anaerobic)Designed for strengthLight in colorFew mitochondriaFewer blood vesselsSlow-twitch fibers:Rely on aerobic respirationDesigned for enduranceDark in colorMany mitochondriaMany blood vesselsWhere in the body would you have examples of each of these?
17 Muscular diseasesFibromyalgia – chronic achy muscles that is not well understoodMuscular dystrophy – group of genetic disorders in which muscles progressively degenerate and weakenMyasthenia gravis – immune system attacks ACh receptor and weakens muscles of the face, neck and extremities-What kind of disorder is this?
18 Amyotrophic lateral sclerosis (ALS) commonly known as Lou Gehrig’s diseasemotor neurons degenerate and die leading to loss of voluntary muscle movement