Anatomy and Physiology Unit Four

Name: Date: Anatomy and Physiology Unit Four - Study Guide 1. What are the 3 basic muscle types found in the body? Cardiac, Smooth, Skeletal 2. What does myo- mean? Muscle 3. What does sarco- mean? Resemble Flesh - Muscle Skeletal Muscle: 4. List and describe the major functions of skeletal muscle. Produce Movement, maintain posture, stabilize joints, Generate heat, Protect organs. 5. List and describe the characteristics of skeletal muscle. Striated, Voluntary, Multinucleated, cylindrical cells. 6. What are the sites of skeletal muscle attachment? Bones, Cartilages Connective tissue coverings and skin via Tendons 7. What attaches skeletal muscles indirectly to bones, cartilage, or connective tissue? Dense Connective Tissue- Tendons or Aponeurosis 8. What is a cordlike structure that often crosses a joint and is an attachment site for muscle? Tendon Smooth Muscle: 9. List and describe the characteristics of smooth muscle. Lacks striations Spindle-shaped cells Single nucleus Involuntary—no conscious control Found mainly in the walls of hollow visceral organs (such as stomach, urinary bladder, respiratory passages) Slow rhythmic contractions- peristalsis Cardiac Muscle: 10. List and describe the characteristics of cardiac muscle. Striations Single nucleus Branching cells Joined to another cardiac muscle cell at an intercalated disc Involuntary Found only in the walls of the heart Muscles are used to help heart pump by twisting and contacting Connective Tissue Wrappings: 11. What are the three connective tissue wrappings and what do they wrap around? Epimysium, Perimysium, Endomysium 12. Why do skeletal muscles need coverings? To protect the fibers (cells) from fraying and friction. Microscopic Anatomy of Skeletal Muscle: 13. What is the sarcolemma? Cell Membrane 14. What are myofibrils? Organelles that contain myofilaments (actin and myosin) 15. What is the difference between light and dark bands? Light “I” bands are actin, Dark “A’ bands are myosin. 16. Draw and label a sarcomere. Explain why they are necessary in a muscle. 17. What causes the banding pattern in a muscle cell? Light and dark bands 18. What does the sarcoplasmic reticulum store and why is it important? Ca2+ which when released causes muscle contraction. 19. What are the four stimulations and contractions of single skeletal muscle cells and what do they all mean? Irritability (also called responsiveness)—ability to receive and respond to a stimulus Contractility—ability to shorten when an adequate stimulus is received Extensibility—ability of muscle cells to be stretched Elasticity—ability to recoil and resume resting length after stretching True or Falce 20. (T/F): Skeletal muscles must be stimulated by a motor neuron to contract. 21. (T/F): A neuromuscular junction is a connection between a nerve cell and a blood cell. 22. (T/F): A neurotransmitter is a chemical released by nerve upon the arrival of nerve impulses in the axon terminal. 23. (T/F): ACh is the neurotransmitter that stimulates smooth muscle. 24. (T/F): The synaptic cleft is a gap between the nerve and muscle that is filled with interstitial fluid. 25. (T/F): Muscle force depends upon the number of fibers stimulated. 26. (T/F): Contraction of more fibers results in less muscle tension. 27. (T/F): Muscles continue to contract even if they run out of energy. 28. (T/F): ATP is the immediate source of energy for muscle contraction. Transmission of Nerve Impulse to Muscle: 29. Put the order of when a nerve impulse reaches the axon terminal of the motor neuron in order: a. ACh diffuses across the synaptic cleft and attaches to receptors on the sarcolemma of the muscle cell. b. Calcium ion entry causes some synaptic vesicles to release ACh. c. If enough ACh is released, the sarcolemma of a muscle cell releases calcium which starts the sliding filament mechanism. d. Calcium channels open, and calcium ions enter the axon terminal of a nerve cell. ____d_____ → ____b_____ → ____a_____ → _____c____ The Physiology of Muscle Contraction and Sliding Filament Theory: 30. Explain why calcium is needed in the sarcoplasm? Calcium bids to troponin, changing its shape. This causes troponin to pull up on tropomyosin moving it out of the way and exposing the binding sites on actin for myosin to pull on it. 31. What is the difference between troponin and tropomyosin? Troponin “witch” holds Tropomyosin “spell” in front of actin. 32. Put the sliding filament theory in order. Be able to explain each step. a. Myosin Crossbridge b. Energize Myosin c. Release d. Power Stroke ___b______ → ___a______ → ___d______ → _____c____ 33. What is the difference between the types of muscle contractions, isotonic and isometric? Isotonic- muscle moves, Isometric- Muscle tense but doesn’t move. 34. What is the difference between the body movements, origin and insertion? Origin- muscle attachment that doesn’t move. Insertion- Muscle attachment that moves to the origin. Types of Body Movements: 35. Flexion 36. Extension 37. Rotation 38. Abduction 39. Adduction 40. Circumduction 41. Dorsiflexion 42. Plantar flexion 43. Inversion 44. Eversion 45. Supination 46. Pronation 47. Opposition _42__ Depressing the foot (pointing the toes) __35_ Decreasing the angle of the joint by bringing two bones closer together. _44__ Turning sole of foot laterally __37_ Movement of a bone around its longitudinal axis. _46__ Forearm rotates medially so palm faces posteriorly _36__ Opposite of flexion. Increases angle between two bones. _41__ Lifting the foot so that the superior surface approaches the shin. __43_ Turning sole of foot medially. _38__ Movement of limb away from the midline. _45__ Forearm rotates laterally so that palms face anteriorly. _39__ Movement of limb toward the midline. _47__ Moving thumb to touch the tips of other fingers on the same hand. __40_ Moving in a circle.