The Muscular System Support Systems Unit 2 Vocabulary

The Muscular System Support Systems Unit 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, tendin/o tendon

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

Vocabulary- suffixes • • -algia -ar -ceps -cyte pain pertaining to heads cell • -duction act of leading • -genesis production of • • inflammation -itis -oma -osis -pathy tumor abnormal condition disease • • -plasty -plegia -rrhaphy -rrhexis -tome -tomy -trophy • -um surgical repair paralysis sutures rupture instrument to cut incision development, nourishment structure, thing

Vocabulary- abbreviations and terms • MRI magnetic resonance imaging • Antagonist the muscle that does the opposite motion • Agonist prime mover, the muscle that does most of the work • Insertion the distal attachment/ the moving end • Involuntary does not need conscious thought • Origin the proximal attachment/ the stable end • Striations striped • Synergist • Thermogenesis • Voluntary helper muscle heat production needs conscious thought

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

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

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

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

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

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

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

Skeletal Muscle Tissue

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

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

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

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

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

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

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

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

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

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

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)

Anterior Skeletal Muscles

Posterior Skeletal Muscles

Diseases and Disorders of the Muscular System

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).

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

Strains cont. • 3 types of strains – – – • 1 st degree occurs when the muscle is stretched causing micro-tears in the muscle fibers 2 nd degree sprain occurs when the muscle or tendon is partially torn 3 rd 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)

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

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

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.