Anatomy: Myosin and Muscle Contraction Essay

Submitted By dj191553
Words: 1711
Pages: 7

11/5/14 F2F a and p The Muscular System Skeletal Muscle Tissue 1. Fill in the characteristics of the three muscle types Muscle TypeCardiacSkeletalSmoothShape of cellBranching chains of cells, uni or bi nucleated striations nucleus in center lots of mitochondria intercalated discs - 2 parts Gap junctions and desmosomeSingle, very long cylindrical, multinucleated cells with obvious striations (nucleus at periphery) lots of mitochondriaSingle, spindle shaped cells (thick in the middle and tapered at the end), uninucleated (in the center) little mitochondria dense bodies of nucleiStriationsControl 2. What attaches muscles to bone __tendons___________________. 3. The whole muscle is composed of muscle cells (fibers) grouped in bundles called ____ fascicles __________. 4. Name the connective tissue coverings surrounding the following Whole muscle ____ Epimysium ______________ Fascicles ____ Perimysium ______________ Muscle cell ________ Endomysium __________ 5. Match the following three terms with their definitions Sarcolemma - endoplasmic reticulum in muscle cell Sarcoplasmic reticulum - intracellular fluid around organelles Cytosol - plasma membrane of muscle cell 6. Match the following three terms with their definitions Terminal cisternae - T-tubule 2 terminal cisternae T-tubules - part of sarcolemmacarries action potential Triad - part of sarcoplasmic reticulumstores calcium ions 7. Myofibrils consist of contractile proteins called _____ Myofilaments ______________. Name the two types and what theyre composed of ____ thin filament ___________ composed of ______ The protein Actin _____________ _______ thick filament ________ composed of _____ The protein myosin. ______________ 8. Arrangement of myofilaments. Give the letter name of each band Dark band ( _ A __ band Light band ( _ I __ band Match two definitions with each band The I band - contains only thin filaments The A band - contains both thick and thin filaments The A band - defined by length of thick filament The I Band - defined as distance between two thick filaments 9. Define the following terms Z line (disc) ____ A protein disk which anchors thin filaments and connects adjacent myofibrils. _________________________________________________ H zone ___ The region between the thin filaments In the A band. ______________________________________________________ 10. What happens to these areas during contraction Z line (disc) _________ It moves closer together. ____________________________________________ H zone _______ The muscles shorten. __________________________________________________ 11. Define these two terms M line ____________ The m line consists of protein fibers that connect neighboring thick filaments. _____________________________________________ Sarcomere _____________ The region of the myofibril between two z lines Contractile unit of the muscle cell. _________________________________________ ________________________________________________________________ 12. Organization of muscle. Put the following components in order, from smallest to largest 4.fascicle smallest is 1 largest is 5 2.myofibril 1.myofilament 5.muscle 3.muscle fiber (cell) The Muscular System Neuromuscular Junction 1. What insulates each muscle cell ______ endomysium___________________ 2. Synaptic vesicles in the axon terminal of a motor neuron contain what neurotransmitter _______ acetylcholine__________________ 3. An action potential in the axon terminal of a motor neuron opens what type of ion channels ________ calcium channels_________________ 4. By what means of membrane transport does the neurotransmitter leave the axon terminal _______ exocytosis__________________ 5. Binding of neurotransmitter to the receptors on the motor endplate open what type of ion channels _________ chemically gated________________ 6. Opening of these channels leads to ____ depolarization ___________ of the motor endplate. 7. How is the neurotransmitter removed from the