Anatomy-Muscular System

1. Anatomy-Muscular System Muscle Types, Characteristics & Function

2. Bell Work • Grab your note taker from the front table • Discuss in your groups the anatomical movements at each joint • Be ready to demonstrate different anatomical movements!

3. Objectives • Students will be able to: • Define terms for muscle types & characteristics • Identify muscle types, characteristics & function • Label & give examples of muscle types • Compare muscle response to USE and DISUSE • List skeletal muscle contractions & response to stimulus

4. Metric Length of muscle Myo Muscle Tendon Connects muscle to bone Contraction Shortening or tensing of a muscle Striated Striped Voluntary Conscious control by will/choice Involuntary Not under conscious control Terminology

5. General Characteristics • Muscles provide ACTION for the body • Excitable • Muscles are electrically excitable • Action occurs when nerve cell stimulates the muscle cell • Contractable • Muscle cells contract • Shorten or tense

6. General Characteristics • Extensible • Ability to stretch from the normal resting length • Elastic • Ability to return from a stretch to normal resting length

7. Muscle Types-Smooth • Characteristics • Occurs in layers in walls of hollow internal organs • Blood vessels, digestive system, urinary system & other internal organs • Involuntary

8. Muscle Types-Smooth • Structure • Elongated cells with tapered ends • Not striated • Shorter than skeletal muscle cells

9. Anatomy-Muscular SystemMuscle Types-Smooth • Function • Slower to contract & relax • Can maintain longer contraction (endurance) • Wave like contractions

10. Muscle Types-Smooth • Smooth Muscle Cells • Microscope View • Stained

11. Muscle Types-Smooth • Myofibrils • Contractile part of muscle fiber • Nucleus • Hereditary material, controls metabolism • Sarcoplasm • Protein to control cell metabolism • Cell Membrane • Surrounds cell Myofibrils Nucleus Sarcoplasm Cell Membrane

12. Muscle Types-Cardiac • Characteristics • Occurs only in the heart • Involuntary

13. Muscle Types-Cardiac • Structure • Striated cells joined end to end • Cells interconnected in branching networks • Intercalated disks between cells to hold cells together

14. Muscle Types-Cardiac • Function • Capable of long contractions • Has strength & appearance of skeletal muscle • Has endurance of smooth muscle

15. Muscle Types-Cardiac • Cardiac Muscle Cells • Microscope View • Stained

16. Muscle Types-Cardiac Striations Branch • Striations • Stripes • Intercalated Disks • Separate cells & hold cell together • Nucleus • Contains hereditary material & controls cell metabolism Nucleus Intercaladed Disks

17. Muscle Types-Skeletal • Characteristics • Attached to bone by a tendon • Function together with bones to provides movement • Voluntary

18. Muscle Types-Skeletal • Structure • Striated • Cylindrical shape with rounded ends • Covered by loose connective tissue called “fascia”

19. Muscle Types-Skeletal • Function • Contraction occurs when muscle cell is stimulated by an electro-chemical impulse from a nerve • Muscle contracts & moves body part

20. Muscle Types-Skeletal • Skeletal Muscle Cells • Microscopic View • Stained

21. Muscle Types-Skeletal • Epimysium • Connective tissue surrounding muscle • Perimysium • Connective tissue surrounding bundle of fibers • Endomysium • Connective tissue surrounding muscle fiber Blood Vessel Perimysium Endomysium Epimysium Bone Tendon

22. Muscle Types-Skeletal • Fascicle • Small bundle • Muscle fiber • Elongated contractile cell Muscle Fiber Fascicle Blood Vessel Endomysium Perimysium Epimysium Bone Tendon

23. Skeletal Muscle • Response to Use • Hypertrophy • Increase in muscle fiber size • Not in # muscle fibers • More forceful contraction

24. Skeletal Muscle • Response to Disuse • Atrophy • Decrease in muscle fibersize • Not in # muscle fibers • Less forceful contraction

25. What does that mean? • Contraction strength directly related to diameter of muscle fiber • The BIGGER the muscle fiber – the more you have used that muscle • The SMALLER the fiber – the Less you have used that muscle

26. 3 Types of Muscle Contractions • Isometric • Muscle contracts but does not shorten • Concentric • Muscle shortens during contraction • Eccentric • Muscle lengthens during contraction

27. Muscle Response • Threshold Response • Minimal strength of stimulus to get a contraction • Muscle remains unresponsive until a certain strength of stimulus is applied

28. Muscle Response 2. All-or-None Response • Muscle fibers are completely relaxed or contracted • Stimulus must be threshold strength or greater to get a contraction • No Partial Contraction • of muscle fibers • Either you contract or you don’t!

29. Muscle Types-Skeletal

30. Wrap it up… • On a sheet of paper… • List an example of • Smooth muscle • Cardiac muscle • Skeletal muscle • AND give me • One characteristic • Its structure • One function • TURN IN ONCE YOU ARE FINISHED! • Example: • Smooth muscle (give example) • Characteristic • Structure • Function