Lab 7: Muscles and Muscle Tissue PDF

Lab 7: Muscles and Muscle Tissue Note: You MUST submit your answers in the untimed quiz on Blackboard for credit. I recommend that you work through it prior to opening the quiz; write your answers on the PDF, a piece of paper, or in a Word document; then open the...

Lab 7: Muscles and Muscle Tissue Note: You MUST submit your answers in the untimed quiz on Blackboard for credit. I recommend that you work through it prior to opening the quiz; write your answers on the PDF, a piece of paper, or in a Word document; then open the quiz in Blackboard to fill out and submit. 1. Match the description to the associated structure. Description Structure A. Connective tissue surrounding a bundle of muscle fibers Endomysium B. Bundle of muscle fibers Epimysium C. Smallest contractile unit of a muscle Fascicle D. Connective tissue sheath that surrounds entire muscle Myofibril E. Areolar connective tissue that surrounds each muscle fiber Myofilament F. Plasma membrane of the muscle fiber Perimysium G. Organelle with a banded appearance within muscle fibers Sarcolemma H. Actin or myosin containing structure Sarcomere I. Collagen fiber cord that attaches muscle to bone Tendon 2. Label the structures in a muscle. 1. 2. 3. 7. 4. 5. 6. 3. Label the components of a muscle fiber. 1. 2. 3. 4. 5. 6. 7. 8. 4. Draw a diagram of a myofibril (microscopic anatomy of a muscle fiber), labeling all the components (sarcomere, thin filament, thick filament, elastic filament, H zone, Z line, A band, etc.) **NOTE: when you submit on Blackboard you will be submitting a digital file.** 5. Label the components of a muscle fiber. 1. 3. 2. 4. 5. 6. 7. 8. 6. Label the components of a muscle fiber. 1. 2. 3. 7. Name the filament type and label the components. 1. 6. 3. 7. 2. 4. 8. 10. 5. 9. 8. Label the structures at the neuromuscular junction. 1. 3. 2. 4. 5. 9. Fill in the blank. What happens at the neuromuscular junction. 1. ______ ______ arrives at axon terminal via axon of motor neuron Voltage-gated 2. ______ channels open; 3. ______ enters motor neuron Calcium entry causes synaptic vesicles to release 4. ______ into 5. ______ ______ via exocytosis ACh diffuses across synaptic cleft and binds to ACh receptors (6. ______ gates) on 7. ______ Channels (gates) open 8. ______ enter muscle fiber and 9. ______ exit, resulting in membrane potential to become 10. ______ negative (end plate potential) Once membrane potential reaches 11. ______ value, action potential propagates along sarcolemma Neurotransmission stops when ACh leaves synaptic cleft (diffuses away or degraded by acetylcholinesterase) 10. Label the order of the steps in excitation-contraction coupling. ____ AP is propagated along sarcolemma and down into T tubules ____ Cross bridges form and contraction begins ____ Voltage-sensitive proteins in tubules change shape and stimulate Ca2+ release from SR into cytosol ____ Ca2+ binds to troponin causing troponin to change shape, removing blocking tropomyosin, and exposing the myosin- binding sites on thin filaments 11. Label the phases of an isometric muscle twitch. 1. 2. 3. 12. Match the description to the term. Description Term A. Muscle lengthens while doing work Isotonic contractions B. Length of muscle does not change during contraction Isometric contractions C. Muscle shortens while doing work Concentric contractions D. Muscle changes in length, but the amount of tension remains Eccentric contractions relatively the same 13. Label the sarcomere length/stage. 2. 3. 1.