The Muscular System

1. The Muscular System Support Systems Unit 2

2. Vocabulary- combining forms Cardi/o heart Fasci/o fascia, connective tissue Fibr/o fiber, fibrous tissue Leiomy/o smooth muscle Muscul/o muscle My/o muscle Ten/o, tend/o, tendin/o tendon

3. Vocabulary- prefixes A- or an- without or not Ab- away Ad- towards Bi- two Hemi- half Hyper- excessive, above normal Intra- within Quadri- four Tri- three

4. Vocabulary- suffixes • -algiapain • -ar pertaining to • -ceps heads • -cytecell • -duction act of leading • -genesisproduction of • -itis inflammation • -omatumor • -osisabnormal condition • -pathydisease • -plasty surgical repair • -plegia paralysis • -rrhaphy sutures • -rrhexis rupture • -tome instrument to cut • -tomy incision • -trophy development, nourishment • -um structure, thing

5. Vocabulary- abbreviations and terms MRImagnetic resonance imaging Antagonistthe muscle that does the opposite motion Agonistprime mover, the muscle that does most of the work Insertionthe distal attachment/ the moving end Involuntarydoes not need conscious thought Originthe proximal attachment/ the stable end Striationsstriped Synergisthelper muscle Thermogenesis heat production Voluntary needs conscious thought

6. Functions of the Muscular System • Heat Production (thermogenesis) • Heat is a byproduct of muscle contraction • Movement Facilitation • Muscles shorten and pull on bones which produces movement • Structure (postural support) • Contraction of muscles keeps us upright and maintains posture

7. Functions cont. • Protection of Internal Organs • Contraction of abdominal muscles causes them to become hard and offers protection to the underlying organs • Other muscles can contract prior to receiving a blow thus protection bones and soft tissue. • Controls the volume of hollow organs • Smooth muscle surrounds our hollow organs and contractions propel the substances through them, aid in their emptying, or helps control their volume • Stomach and small intestines • The bladder • Blood vessels

8. Types of Contractibility • Voluntary- contractions controlled by conscious thought or will • Involuntary- contract due to unconscious impulses sent by the autonomic nervous system or certain specialized cells or hormones

9. Muscle Appearance Striated- stripes, muscles that on a microscopic level have cross fiber stripes Non-striated- Not having stripes, muscles cells that microscopically have a smooth appearance

10. Cardiac Muscle • Forms the bulk of heart wall (Myocardium) • Striated • Involuntary (typically) • Cardiac fibers typically have a centrally located nucleus • Intercalated discs • Strengthens cardiac muscle tissue • Allows for special wringing muscle contraction

11. Smooth Muscle • Located in walls of hollow internal surfaces such as: • blood vessels - stomach • urinary bladder - intestines • Non-striated in appearance • Involuntary (typically) • Contractions usually move things along, from point A to point B (peristalsis)

12. Skeletal Muscle • Attached to bones • Striated appearance under a microscope • Voluntary control (conscious control) • Allow for postural support and movement of body parts, both axial and appendicular

13. Skeletal Muscle Tissue

15. Tendons • Connect muscle to bone • Made of dense fibrous connective tissue that surrounds the muscle belly and extends further, becoming tendon

16. Muscle Actions Agonist- the prime mover, or the muscle that does the most work Antagonist- the muscle that does the opposite motion Fixator- holds the body part in place while the action takes place Synergist- the helper muscle, assists in making the motion happen

17. Motions Peristalsis- a wave like motion by smooth muscle to advance substances Abduction- movement away from midline Adduction- movement towards midline Flexion- decreasing a joint angle Extension- increasing a joint angle Hyperextension- extension past normal extension, or past anatomical position

18. Motions Plantarflexion- specific to ankle motion, pointing the toes Dorsiflexion- specific to ankle motion, pulling the toes towards the shin Supination- turning palm up Pronation- turning palm down Rotation- movement around an axis Circumduction- cone shaped motion

19. Origin vs. Insertion Origin- the most proximal end of the muscle, the non moving end, or where the muscle starts Insertion- the distal end of a muscle, the moving end, or where the muscle goes to

20. Location and Function of Skeletal Muscles • Biceps Brachii • Origin: anterior shoulder • Insertion: anterior elbow • Action: elbow flexion • Triceps Brachii • Origin: posterior shoulder • Insertion: posterior elbow • Action: elbow extension

21. Location and Function of Skeletal Muscles • Trapezius • Origin: cervical and thoracic spine • Insertion: spine of the scapula • Action: extends or hyperextends the head and neck, (also helps with shoulder retraction and elevation and depression) • Latissimus Dorsi • Origin: Lower thoracic and lumbar spine as well as the pelvis • Insertion: proximal humerus • Action: extends a flexed arm or hyperextends the arm from the anatomical position

22. Location and Function of Skeletal Muscles • Deltoid • Origin: clavicle and spine of the scapula • Insertion: lateral humerus • Action: shoulder abduction • Pectoralis Major • Origin: upper ribs along the sternum and clavicle • Insertion: humerus • Action: adduction

23. Location and Function of Skeletal Muscles • Rectus Abdominis • Origin: anterior lower ribs • Insertion: pubic bones • Action: lumbar spine flexion • Diaphragm • Origin: central tendon (fibrous tissue) • Insertion: circumference of lower rib cage • Action: expands chest for breathing

24. Location and Function of Skeletal Muscles • Quadriceps (group of 4 muscles) • Origin: anterior pelvis and proximal femur • Insertion: anterior tibia • Action: knee extension • Hamstrings (group of 3 muscles) • Origin: ischium and posterior femur • Insertion: posterior tibia and fibula • Action: knee flexion

25. Location and Function of Skeletal Muscles • Gluteus Maximus • Origin: ilium, sacrum, and coccyx • Insertion: femur • Action: extends hip • Gastrocnemius • Origin: femur • Insertion: calcaneus (heel bone) • Action: plantar flexes ankle (when knee is straight) • Soleus • Origin: tibia and fibula • Insertion: calcaneus (heel bone) • Action: plantar flexes ankle (when knee is bent)

26. Anterior Skeletal Muscles

27. Posterior Skeletal Muscles

28. Diseases and Disorders of the Muscular System

29. Tendonitis • Tendonitis is characterized by Inflammation of the tendons due to overuse or age-related changes of the tendon. • It is common in individuals who begin a new exercise or increase their level of exercise. • Age-related tendonitis is due to the loss of elasticity and the ability of the tendon to glide smoothly. • Treatment includes: rest, ice, compression, and elevation (RICE).

30. Strains • A tearing of a muscle or its attaching tendon • Occurs when a muscle receives a stress that overcomes its strength • Sudden, quick heavy lifting • During sports • While performing work tasks

31. Strains cont. • 3 types of strains • 1st degree occurs when the muscle is stretched causing micro-tears in the muscle fibers • 2nd degree sprain occurs when the muscle or tendon is partially torn • 3rd degree sprain occurs when the muscle is completely ruptured • Signs and symptoms • Pain, especially when the muscle is contracting which limits function, swelling, and bruising • Treatment • Rest, Ice, Compression, Elevation (RICE)

32. Muscle Spasm An involuntary muscle contraction Also called a “Charlie Horse” or “muscle cramp” Main causes are electrolyte imbalances, dehydration and fatigue

33. Muscle Spasm cont. • Initial treatment is to put the muscle that has the spasm on stretch • If spasm persists ice or heat can be used • Prevention incudes maintaining a proper diet, drinking plenty of water and proper conditioning • Sports drinks may be beneficial during exercise to help replace lost sodium due to sweating

34. Muscular Dystrophy An inherited disorder in which the muscles are missing a certain protein causing degeneration of muscle tissue Causes progressive weakness and loss of function of the affected muscles There is no cure but physical therapy can lessen the severity of the disorder.