| Question |
Answer |
| What is the function of Skeletal Muscle? | Movement and Stability of Skeleton |
| What is a Motor Unit/Muscle Fiber? | collection of 10-2000 Cells innervated by branches of ONE Motor Nerve |
| When do Motor Units respond to a Stimulus? | when Depolarized |
| What are Myofibrils? | bundles of Myofilaments |
| What are Myofilaments? | Contractile Proteins - Myosin, Actin |
| What are z-Lines? | Protein anchoring discs for Actin |
| How does a Sarcomere shorten? | Myosin over Actin |
| What are 4 characteristics of Skeletal Muscle? | 1. resting Potential (like Neurons); 2. Voluntary, quick Contraction; 3. All-or-None contraction; 4. Biochemical Specialization |
| what is meant bu All-or-None Contraction? | ALL Cells of a given Motor Unit contract FULLY, Simultaneously, or not at all |
| What are the 2 types of Biochemical Specialization? | SLOW-Oxidative "Red" Fibers, FAST-Glycolytic "White" Fibers |
| What are some characteristics of SLOW-Oxidative Fibers? | 1. slow, Sustained contractions; 2. HIGH Myoglobin; 3. MANY Mitochondria, LITTLE Glycogen; 4. NUMEROUS Capillaries; 5. SMALL Motor Units; 6. DIFFICULT to Fatigue |
| What are some characteristics of FAST-Glycolytic Fibers? | quick, Brief contractions; 2. LITTLE Myoglobin; 3. FEW Mitochondria, LOTS Glycolytic Enzymes; 4. FEW Capillaries; 5. HUGE SR; 6. HIGH Glycogen; 7. LARGE Motor Unit; 8 .LARGE Diameter; 9. EASILY Fatigued |
| Name 2 Glycolytic Enzymes. | Pyruvic & Lactic Acids |
| Why do "White Fibers" have a lot of Glycogen? | need because Anaerobic --> less ATP |
| How does exercise change or not change Skeletal Muscle? | INCREASES Vascularity, Mitochondria, and amount of Myosin & Actin |
