The Muscular System Support Systems Unit 2

Functions of the Muscular System Heat Production (thermogenesis) Breaking of ATP during muscle contraction Movement Facilitation Muscles pull on the skeletal levers Structure (postural support) Muscles hold parts of the skeleton in place Protection of Internal Organs The abdominal muscles are thick and protect the abdominal and pelvic cavity organs

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

Cardiac Muscle Tissue

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)

Smooth Muscle Tissue

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

Connecting Tissues Tendon – muscle to bone Ligament- bone to bone

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

Location and Function of Skeletal Muscles Biceps brachii- anterior surface of arm between the shoulder and elbow, flexes the elbow Triceps brachii- posterior aspect of arm between the shoulder and elbow, extends the elbow Trapezius- attaches to the spine from the occiput through the thoracic region and to the spine of the scapula, extends or hyperextends the head and neck, (also helps with shoulder retraction and elevation and depression) Deltoid- covers the cap of the shoulder, abducts the arm Diaphragm- connects to the lower ribs and runs through the entire body, deflects the diaphragm inferiorly increasing volume of the thoracic cavity

Location and Function of Skeletal Muscles Pectoralis major- attaches to the upper ribs along the sternum and to the humerus, adducts the arm Latissimus dorsi- attaches along mid to lower spine and pelvic and to the humerus, extends a flexed arm or hyperextends the arm from the anatomical position Rectus abdominus- attaches to the lower ribs and to the pelvic anteriorly, flexes the lumbar spine Gastrocnemius-attaches to the tibia and lower femur and uses the achilles tendon to attach to the calcaneous (heel bone), plantar flexes the ankle when the knee is in extension

Location and Function of Skeletal Muscles Soleus- attached deep to the gastrocnemius on the tibia and uses the achilles tendon to attach to the calcaneous, plantarflexes the ankle when the knee is bent Hamstrings- posterior thigh between the hip and knee, flexes the knee Quadriceps- anterior thigh between the hip and knee, extends the knee Gluteus maximus- posterior pelvis, extends a flexed thigh or hyperextends the thigh from the anatomical position

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).

Sprain A sprain is an injury to a ligament, which is the fibrous tissue that connects bones to other bones. There are three grades of sprains: 1st Degree Sprain = stretching of ligaments 2nd Degree Sprain = partial tearing of ligaments 3rd Degree Sprain = complete tear of ligaments

Three Degrees of Sprains

Strains Muscle strain or muscle pull or even a muscle tear implies damage to a muscle or its attaching tendons. This can occur due to excessive pressure on muscles during the course of normal daily activities, with sudden, quick heavy lifting, during sports, or while performing work tasks.

Degrees of Muscle Strains First degree strain - a mild strain when only a few muscle fibers are stretched or torn. The injured muscle is tender and painful, but has normal strength. Second degree strain - a moderate strain with a greater number of injured fibers. There is more severe muscle pain and tenderness. There is also mild swelling, some loss of strength, and a bruise may develop. Third degree strain - this strain tears the muscle all the way through. There is a total loss of muscle function.

Careers Orthopedic Surgeon Certified Athletic Trainer Medical Illustrator Massage Therapist

Orthopedic Surgeon Medical Doctor who specializes in musculoskeletal ailments including acute, chronic, traumatic and overuse injuries Performs surgeries on musculoskeletal disorders such as ACL tears, Knee replacements, Scoliosis surgery Attends 4 year undergrad + 4 year medical school + 5 year orthopedic residency program + 1 year fellowship Salary- $300,000++ Arthroscopic surgery

Certified Athletic Trainer Responsible for prevention, recognition, evaluation, immediate care and rehabilitation of injuries Work at high schools, universities, professional sports, gyms, industry, military, hospitals and clinics Bachelors Degree $35,000 + Athletic Training- Smooth Professional

Medical Illustrator Artists who have detailed knowledge of the human body Create graphic representations of medical or biological subjects for textbooks, pamphlets, exhibits, films, legal procedures, teaching models Pre-med/ Art Major Masters of Medical Illustrating Salary - $33,000-60,000 Job outlook is small and competitive, BUT growing because of technology

Massage Therapist Sports Massage Manipulate patients body with pressure, tension or vibration manually or with mechanical aids Work in hospitals, nursing homes, sports and fitness centers, spas, beauty salons, cruise ships, private offices Graduate from accredited Massage school (8 months to 12 months)and pass License exam Can specialize in pediatric massage, sports massage…. Salary varies widely Where do MT work and how much do they make Sports Massage

Vocabulary- word parts My/o- muscle (myofibril is a muscle fiber) Ab- prefix, away (abduction) Ad- prefix, towards (adduction) Bi- prefix, two (biceps) Tri- prefix, three (triceps) Quad- prefix, four (quadriceps) Contra- prefix, opposite or against (contralateral- pertaining to the other side) Dys- prefix, bad, difficult, or painful (dysphagia- difficulty swallowing) -algia- suffix, pain (myalgia- muscle pain)

Vocabulary Ligament- connective tissue that holds bone to bone Tendon- connective tissue that hold muscle to bone Tendonitis- inflammation of a tendon Sprain- stretch or tear of a ligament Strain- stretch or tear of a muscle or tendon Myocardium- heart muscle Thermogenesis- heat production Striations- stripes MRI- Magnetic Resonance imaging