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Muscular System. Muscles and Muscle Tissue. Muscle Review Questions . ADD THESE TO YOUR PACKET ON BACK! 1. What are the three types of muscle tissue? What are their functions? Where are they located in the body? Voluntary ? Striated? 2. What are the four functions of muscle?
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Muscular System Muscles and Muscle Tissue
Muscle Review Questions • ADD THESE TO YOUR PACKET ON BACK! • 1. What are the three types of muscle tissue? What are their functions? Where are they located in the body? Voluntary? Striated? • 2. What are the four functions of muscle? • 3. What are striations and why are they important to the muscle fibers/whole body?’ • 4. What are the 5 different sized stringlike structures that make up muscle? (Macroscopic to microscopic) • 5. What is the name of the two myofilaments? What are the myofilament’s function in the body?
Microscopic Anatomy of a Skeletal Muscle Fiber PG 282-onwards! • Investigate the microanatomy of a muscle cell with your group. • 1. Determine what a “sarcomere” is. How big is it? What function does it serve in the muscle cell? • 2. Where are actin and myosin in the sarcomere? What filaments are “thick? Which filaments are “thin?” • 3. What are A bands? I Bands? • 4. What are H zones? Z Discs? M lines? • 5. How do all of these bands and zones and discs change when muscle contracts? (pg 289)
Agenda Welcome back! I missed you guys, had some good food and rest over break in Minnesota, but it’s time to get back to education. :-D 3 Weeks left in the semester! Now is the time to give it everything you’ve got! Be gritty, passionate, and persistent and finish this semester strong, no matter where your grade is at.
Agenda Finish Introduction to Muscular System Exit Ticket (1st and 5th period), Review all other periods. Notes 1pg on Muscles Video on Muscles Poke-a-muscle game!
Some Muscle Terminology Myology: the scientific study of muscle muscle fibers = muscle cells myo, mys & sarco: word roots referring to muscle
Introduction All movements require muscle which are organs using chemical energy to contract
Three Types of Muscle Skeletal muscle Cardiac muscle Smooth muscle
Skeletal Muscle • Most are attached by tendons to bones • Cells are multinucleate • Striated—have visible banding • Voluntary—subject to conscious control • Sites of muscle attachment • Bones • Cartilages • Connective tissue coverings
Smooth Muscle Lacks striations Spindle-shaped cells Single nucleus Involuntary—no conscious control Found mainly in the walls of hollow organs
Cardiac Muscle Striations Usually has a single nucleus Branching cells Joined to another muscle cell at an intercalated disc Involuntary Found only in the heart
Functions of Muscle Tissue Motion: external (walking, running, talking, looking) and internal (heartbeat, blood pressure, digestion, elimination) body part movements Posture: maintain body posture Stabilization: stabilize joints – muscles have tone even at rest Thermogenesis: generating heat by normal contractions and by shivering
Functional Characteristics Excitability (irritability) the ability to receive and respond to a stimulus (chemical signal molecules) Contractility ability of muscle tissue to shorten Extensibility the ability to be stretched without damage most muscles are arranged in functionally opposing pairs – as one contracts, the other relaxes, which permits the relaxing muscle to be stretched back Elasticity the ability to return to its original shape Conductivity (impulse transmission) the ability to conduct excitation over length of muscle
Microscopic Anatomy of Skeletal Muscle • Myofibrils—long organelles inside muscle cell
Myofibrils complex organelle composed of bundles of myofilaments Sarcomeres segment (portion) of the myofibirls. CONTRACTILE UNIT between 2 Z disks Myofilamentsproteins that are within one sacromere Anatomy of Skeletal Muscle Fiber = Muscle cell
Myofilaments There are two types of Myofilaments: Thin filaments: made of actin I bands are the thin filaments Thick filaments: made of myosin H zone consists of only thick filaments A bands are made up of overlapping thick and thin filaments
Label the following muscles on the anterior body! • 1. Biceps brachii • 2. Wrist Flexors • 3. Deltoid • 4. Pectoralis Major • 5. Serratus Anterior • 6. External Obliques • 7. Rectus Abdominis • 8. Tensor Fascia Latae • 9. Gastrocnemius* • 10. Quadriceps • 11. Sartorious • 12. Tibialis Anterior • 13. Adductors • 14. Trapezius * • 15. Frontalis (guess where it is) • 16. Masseter (new one) • 17. Soleus • * = on back but still visible