Ch.6 Muscular System - Lecture notes Ch. 6 PDF

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Medical Terminology for Health Care Professionals, 9th ed....

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Ch.6 Muscular System The muscular system is composed of all the muscles in the body and works in coordination with the skeletal and nervous systems.  Muscular development in newborns and infants progresses from heat to foot.  Muscles provide the mechanism for movement of the body and locomotion from one place to another.  Muscles produce heat and help the body maintain posture and stability.  There are 3 basic types of muscles:  Skeletal, smooth, and cardiac  The muscles are the primary tissues of the system. They make up approximately 42% of a person's body weight and are composed of long, slender cells known as fibers.  Muscle fibers are of different lengths and shapes and vary in color from white to deep red.  Each muscle consists of a group of fibers held together by connective tissue and enclosed in a fibrous sheath of fascia.  Each fiber within a muscle receives its own nerve impulses and has its own stored supply of glycogen, which it uses as fuel for energy.  Muscles must be supplied with proper nutrition and oxygen to perform correctly; these essentials are supplies via the blood, thus blood and lymphatic vessels permeate muscle tissues.  Muscles- cause movement, help to maintain posture, and produce heat  Skeletal muscles- produce various types of body movement through contractility, extensibility, and elasticity  Smooth muscles- produce relatively slow contraction with greater degree of extensibility in the internal organs, especially organs of the digestive, respiratory, and urinary tract, plus certain muscles of the eyes and skin, and walls of blood vessels  Cardiac muscle- contraction of the myocardium, which is controlled by the autonomic nervous system and specialized neuromuscular tissue located within the right atrium  Tendons- bands of connective tissue that attach muscles to bones Types of Muscles  Skeletal muscle, smooth muscle, and cardiac muscle are the 3 basic types of muscles in the body. They are composed of different types of muscle tissue (e.g., striated or smooth) and classified according to their functions and appearance 

Skeletal Muscle  Skeletal muscle (also known as voluntary or striated muscles) are controlled by the conscious part of the brain and attach to the bones.  These muscles have a cross-striped appearance (striated) and vary in size, shape, and arrangement of fibers, and means of attachment to bones.  Sternocleidomastoid- rotates and laterally flexes neck (direction: anterior)

Trapezius- draws head back and to the side; rotates scapula (direction: anterior/posterior)  Deltoid- raises and rotates arms (direction: anterior/posterior)  Rectus femoris- extends leg and assists flexion of thigh (direction: anterior)  Sartorius- flexes and rotates the thigh and leg (direction: anterior)  Tibialis anterior- dorsiflexes foot and increases the arch in the beginning process of walking (direction: anterior)  Pectoralis major- flexes, adducts, and rotates arm (direction: anterior)  Biceps brachii- flexes arm and forearm and supinates forearm (direction: anterior)  External oblique- contracts abdomen and viscera (internal organs (direction: anterior)  Rectus abdominis- compresses of flattens abdomen (direction: anterior)  Gastrocnemius- located in the lower leg below the knee;plantar flexes foot and flexes knee (direction: anterior/posterior)  Soleus- plantar flexes foot (direction: anterior)  Triceps- extends forearm (direction: posterior)  Latissimus dorsi- adducts, extends, and rotates arm; used during swimming (direction: posterior)  Gluteus medius- adducts and rotates thigh (direction: posterior)  Gluteus maximus- extends and rotates thigh (direction: posterior)  Biceps femoris- flexes knee and rotates it outward (direction: posterior)  Semitendinosus- flexes and rotates leg; extends thigh (direction: posterior)  Semimembranosus- flexes and rotates leg; extends thigh (direction: posterior)  Achilles tendon- plantar (sole of the foot) flexion and extension of ankle (direction: posterior) located in the lower leg. There are over 600 skeletal muscles in the body that, through contractility, extensibility, excitability, and elasticity, are responsible for the movement of the body Contractility allows muscles to change shape to become shorter and thicker. With extensibility, living muscle cells can be stretched and extended. They become longer and thinner. In excitability, muscles receive and respond to stimulation. With elasticity, once the stretching force is removed, a living muscle cell returns to its original shape. Muscles have 3 distinguishable parts: the body or main portion, an origin, and an insertion. The origin is the more fixed attachment of the muscle to the stationary bone and the insertion is the point of attachment of a muscle to the bone that it moves. The means of attachment is a band of connective tissue called a tendon, which can vary in length from less than 1 inch to more than 1 foot. Some muscles, such as those in the abdominal region, the dorsal lumbar region, and the palmar region, form attachments using a wide, thin, sheetlike tendon known as an aponeurosis. 

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Skeletal muscles move body parts by pulling from one bone across its joint to another bone, with movement occurring at the freely movable (diarthrosis/synovial) joint  Muscles and nerves function together as a motor unit  For skeletal muscles to contract, it is necessary to have stimulation by impulses from motor nerves  Skeletal muscles perform in groups and are classified as follow:  Antagonist- muscle that counteracts the action of another muscle; when one contracts, the other relaxes  Prime mover or agonist- muscle that is primary in a given movement; the movement is produced by its contraction  Synergist- muscle that acts with another muscle to produce and assist movement  All movement is a result of the contraction of a prime mover (agonist) and the relaxation of the opposing muscle (antagonist) Smooth Muscle  Smooth muscle is also called involuntary , visceral, or unsriated and is not controlled by the conscious part of the brain. They are under the control of the autonomic nervous system and, in most cases, produce relatively slow contraction with a greater degree of extensibility.  These muscles lack the cross-striped appearance of skeletal muscle and are smooth.  Included in this type are the muscles of internal organs of the digestive, respiratory, and urinary tract plus certain muscles of the eyes and skin Cardiac Muscle  The muscle of the heart, the cardiac muscle (myocardium), is voluntary but striated in appearance.  It is under the control of the autonomic nervous system and has specialized neuromuscular tissue located within the right atrium  Cardiac muscle differs from the other two muscle types in that contraction can occur even without an initial nervous input.  The cells that produce the stimulation for contraction without nervous input care called pacemaker cells.  Coordinated contraction of cardiac muscle cells in the heart propels blood from the atria and ventricles to the blood vessels of the circulatory system.  Cardiac muscle cells, like all tissues in the body, rely on an ample blood supply to deliver oxygen and nutrients and to remove waste products such as carbon dioxide. The coronary arteries fulfill this function. Functions of Muscles  The following is a list of the primary functions of muscles: 1. Muscles are responsible for movement. The type of movement are locomotion where chemical energy is changed into mechanical energy, propulsion of substances through tubes as in circulation and digestion, and changes in the size of openings as in the contraction and relaxation of the iris of the eye

2. Muscles help to maintain posture through a continual partial contraction of skeletal muscles. This process is known as tonicity 3. Muscles help to produce heat through the chemical changes involved in muscular action Building Your Medical Vocabulary Combining Forms  agon/o- agony, a contest  amputate/o- to cut through  brach/i, brachi/o- arm  cleid/o- clavicle  con- with, together  dactyl/o- finger or toes  dermat/o- skin  duct/o- to lead  fasci/o- a fibrous band  fibr/o- fiber  is/o- equal  mast/o- mastoid process  metr/o- to measure  muscul/o- muscle  my/o (s)- muscle  neur/o- nerve  path/o- disease  prosth/e- an addition  rhabd/o- rod  rheumat/o- discharge  rotat/o- to turn  sarc/o- flesh  scler/o- hardening  stern/o- sternum  synov/o- synovial  ten/o- tendon  therm/o- hot, heat  ton/o- tone, tension  tors/o- twisted  tort/i- twisted  tract/o- to draw  troph/o- nourishment, development  volunt/o- will Word Roots  collis- neck  gravis- grave  levat- lifter

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log- study relaxat- to loosen sert- to gain spastic- convulsive

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Abductor- muscle that on contraction draws away from the middle Adductor- muscle that draws a part toward the middle Amputation- surgical or traumatic removal of a limb, part, or other appendage Antagonist- muscle that counteracts the action of another muscle; when one counteracts, the other relaxes Aponeurosis- a strong, flat sheet of fibrous connective tissue that serves as a tendon to attach muscles to bone or as fascia to bind muscles together or to other tissues as their origin or insertion Ataxia- lack of muscular coordination; an inability to coordinate voluntary muscular movements that is symptomatic of some nervous disorders Atonic- pertaining to a lack of normal bone or tension; the lack of normal muscle tone Atrophy- literally means a lack of nourishment; wasting-away of muscular tissue that may be caused by lack of use or lack of nerve stimulation of the muscle. Lipoatrophy (also called lipodystrophy) is atrophy of fat tissue. This condition can occur at the site of an insulin and/or corticosteroid injection Biceps- muscle with two heads of points of origin Brachialgia- pain in the arm Bradykinesia- slowness of motion of movement Contraction- process of drawing-up and thickening of muscle fiber Contracture- a fibrosis of connective tissue in skin, fascia, muscle, or joint capsule that prevents normal mobility of the related tissue or joint. With a muscular contracture, a muscle shortens and renders the muscle resistant to the normal stretching process. For example, Dupuytren contracture is a thickening and tightening of subcutaneous tissue of the palm, causing the ring and little fingers to bend into the palm so that they cannot be extended Dactylospasm- medical term for cramp of a finger or toes Dermatomyositis- acute or chronic disease with systemic pathology inflammation of the muscles and the skin; a connective tissue disease characterized by edema, dermatitis, and inflammation of the muscles. Occurs in children and adults, and in the latter may be associated with neoplastic disease (cancer) or other disorders of connective tissue. Also referred to as dermatopolymyositis Diaphragm- partition of muscles and membranes that separates the chest cavity and the abdominal cavity. It is the major muscle of breathing Diathermy- treatment using high-frequency current to produce heat within a part of the body; used to increase blood flow but should not be used in acute stage of recovery from trauma Dystonia- condition of impaired muscle tone

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Dystrophin- protein found in muscle cells. When the gene that is responsible for this protein is defective and sufficient dystrophin is not produced, muscle wasting occurs. For example, in Duchenne muscular dystrophy, this protein is absent Dystrophy- any condition of abnormal development caused by defective nourishment, often noted by the degeneration of muscles Exercise- performed activity of the muscles for improvement of health or correction of deformity  Types of Exercise include:  Active exercise- muscular contraction and relaxation by patient  Assistive exercise- muscular contraction and relaxation with the assistance of a therapist  Isometric exercise- active muscular contraction performed against stable resistance, thereby not shortening muscle length  Passive exercise- exercise performed by another individual without patient assistance Range of motion (ROM)- movement of each joint through its full range of motion (FROM); used to prevent loss of mobility or to regain usage after an injury or fracture Relief of tension- technique used to promote relaxation and provide relief from tension Fascia- thin layer of connective tissue covering, supporting, or connecting the muscles or inner organs of the body Fasciitis- inflammation of a fascia Fatigue- state of tiredness occurring in a muscle as a result of repeated contractions Fibromyalgia syndrome (FMS)- disorder that affects the muscles and soft tissues; symptoms include chronic muscle pain (myalgia), fatigue, sleep disorders, irritable bowel syndrome, depression, and chronic headaches. Although the exact cause is still unknown, fibromyalgia is often traced to an injury or physical or emotional trauma. ACR classifies a patient with fibromyalgia is at least 11 of 18 specific areas of the body (called trigger points) are painful under pressure. The location of some these trigger points includes the inside of the elbow joint, the front of the collarbone, and the base of the skull. Treatments for fibromyalgia are geared toward improving the quality of sleep, as well as reducing pain. Fibromyitis- inflammation of muscle and fibrous tissue; also known as fibromyositis First Aid Treatment-RICE (Rest Ice Compression Elevation)- Cryotherapy (use of cold) is the treatment of choice for soft tissue and muscle injuries. It causes vasoconstriction of blood vessels and is effective in diminishing bleeding and edema. Ice should not be placed directly onto the skin. Compression by an elastic bandage is generally determined by the type of injury and physician preference. Some experts disagree on the use of elastic bandages. When used, the bandage should be 3-4 inches wide and applied firmly. Toes or fingers should be periodically checked for blue of white discoloration, indicating that the bandage is too tight. Elevation is used to reduce swelling. The injured part should be elevated above the level of the heart. Flaccid- lacking muscle tone; weak, soft, flabby

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Heat- treatment using application of heat (thermotherapy) can be used 48-72 hours after the injury. Types of thermotherapy include heating pad, hot water bottle, hot packs, infrared light, and immersion of body part in warm water. Hydrotherapy- treatment using scientific application of water; types: hot tub, cold bath, whirlpool, and vapor bath Insertion- point of attachment of muscle to the part that it moves Intramuscular (IM)- pertaining to within a muscle, such as an IM injection Isometric- literally means pertaining to having equal measure; increasing tension of muscle while maintaining equal length Isotonic- pertaining to having the same tone or tension Levator- muscle that raises or elevates a part Massage- kneading that applies pressure and friction to external body tissues Muscle spasm- involuntary contraction of one or more muscles; usually accompanied by pain and limitation of function. A "charley horse" is a common name for a muscle spasm or cramp. Muscle spasms can occur in any muscle in the body, but often happen in the leg. When a muscle is in spasm, it contracts without your control and does not relax Muscular dystrophy (MD)- refers to a group of genetic diseases characterized by progressive weakness and degeneration of the skeletal or voluntary muscles that control movement. The muscles of the heart and some other involuntary muscles are also affected in some forms of MD, and a few forms involve other organs as well. Duchenne muscular dystrophy is the most common form of MD affecting children which is an Xlinked disorder seen mostly in males. Myotonic MD is the most common form affecting adults. Myalgia- pain in the muscle Myasthenia gravid (MG)- chronic autoimmune neuromuscular disease characterized by varying degrees of weakness of the skeletal (voluntary) muscles of the body. Its name, which is Latin and Greek in origin, literally means grave muscle weakness. The primary symptom is muscle weakness that increases during periods of activity and improves after periods of rest Myoblast- embryonic cell that develops into a cell of muscle fiber Myofibroma- tumor that contains muscle and fiber Myograph- instrument used to record muscular contractions Myokinesis- muscular motion or activity Myoma- tumor containing muscle tissue Myomalacia- softening of muscle tissue Myoparesis- weakness or slight paralysis of a muscle Myopathy- muscle disease Myoplasty- surgical repair of a muscle Myorrhaphy- surgical suture of a muscle wound Myosarcoma- malignant tumor derived from muscle tissue Myosclerosis- abnormal condition of hardening of muscle Myositis- inflammation of muscle tissue, especially skeletal muscles; may be caused by infection, trauma, or parasitic infestation Myospasm- spasmodic contraction of a muscle

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Myotome- surgical instrument used to cut muscle Myotomy- surgical incision into a muscle Neuromuscular- pertaining to both nerves and muscles Neuromyopathic- pertaining to a disease condition involving both nerves and muscles Polyplegia- paralysis affecting many muscles Position- bodily posture or attitude; the manner in which a patient's body may be arranged for examination  Anatomic- body erect, head facing forward, arms by the side with palms to the front; used as a standard anatomical position of reference  Dorsal recumbent- on back with lower extremities flexed and rotated outward; used in application of obstetric forceps, vaginal and rectal examination, and bimanual palpation  Fowler- head of the bed or examining table if raised about 18 inches of 46 cm; patient is in a semi-upright sitting position (45-60 degrees) with knees either bent of straight  Knee-chest- on knees, thighs upright, head and upper part of chest resting on bed or examining table, arms crossed and above head; used in sigmoidoscopy, displacement of prolapsed uterus, rectal exams, and flushing of intestinal canal  Lithotomy- on back with lower extremities flexed and both legs placed in stirrups; a gynecologic position used in vaginal examination, Pap smear, vaginal operations, and diagnosis and treatment of diseases of the urethra and bladder  Orthopneic- sitting upright or erect; used for patients with dyspnea, shortness of breath (SOB)  Prone- lying face downward; used in examination of the back, injections, and massage  Sims- lying on left side, right knee and thigh flexed well up above left leg that is slightly flexes, left arm behind the body, and right arm forward, flexed at elbow; used in examination of rectum, sigmoidoscopy, enema, and intrauterine irrigation after labor  Supine- lying flat on back with face upward and arms at the dies; used in examining the head, neck, chest, abdomen, and extremities and in assessing vital signs  Trendelenburg- body supine on a bed or examining table that is tilted at about a 45-degree angle with the head lower than the feet; used to displace abdominal organs during surgery and in treating cardiovascular shock Prothesis- artificial device used to replace an organ or body part, such as a hand, arm, leg, or hip. Quadriceps- muscle that has four heads or points of origin Relaxation- process in which a muscle loosens and returns to a resting stage Rhabdomyoma- tumor of striated muscle tissue Rheumatism- general term used to describe conditions characterized by inflammation, soreness, and stiffness of muscles and pain in joints Rheumatology- study of rheumatic diseases Rheumatologist- one who specializes in rheumatic diseases

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Rigor mortis- stiffness of skeletal muscles seen in death; develops between the 4th and 24th hou...