medical terminology a word-building approach chapter 7 muscular system jane rice, rn, cma-c

MedicalTerminology

A Word-Building Approach

Chapter 7

Muscular System

Jane Rice, RN, CMA-C

Anatomy and Physiology Overview

• The muscular system is composed of all the muscles of the body. They are composed of long slender cells known as fibers.

• Each muscle is made up of a group of fibers held together by connective tissue and enclosed in a fibrous sheath or fascia.

Copyright ©2008 by Pearson Education, Inc.Pearson Prentice Hall

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Medical Terminology, 6eBy Jane Rice

Figure 7.1Skeletal muscle consists of a group of fibers held together by connective tissue. It is enclosed in a fibrous sheath (fascia).

Anatomy and Physiology Overview

• Each muscle has its own blood and lymphatic vessels, its own nerve impulse, and its own supply of glycogen for energy.

Muscular System Animation

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Types of Muscle Tissue

• There are three basic types of muscle tissue classified according to their function and appearance:– Skeletal– Smooth– Cardiac




Figure 7.2Types of muscle tissue.


• Skeletal Muscle– Also known as voluntary or striated muscle.– Controlled by the conscious part of the brain and

attached to bone.– Has a cross-striped appearance; thus striated

muscle.– There are 600 skeletal muscles that are

responsible for the movement of the body.


• The process of muscle movement– Contractility

• Allows muscles to change shape to become shorter and thicker.

– Extensibility• Allows living muscle cells to be stretched and extended;

they become longer and thinner.

– Excitability• Muscles receive and respond to stimulation.

– Elasticity• Once the stretching force is removed, a living muscle

cell returns to it original shape.


• Skeletal muscles have two or more attachments and have three distinguished parts:1. The Body

› Main portion.

2. Origin› The fixed attachment.


• Skeletal muscles have two or more attachments and have three distinguished parts:3. Insertion

› The point of attachment of a muscle to the part that it moves+ Tendon

– The main means of attachment.+ Aponeurosis

– A sheetlike tendon.


• Muscles and nerves work together as a motor unit and perform in groups:– Antagonist

• Muscle that counteracts that action of another muscle.

– Prime Movers or Agonist• Muscle that is primary in a given movement.• Its contraction produces the movement.

– Synergist• Muscle that acts with another muscle to produce

movement.

Shoulder Movement Animation

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Forearm Movement Animation

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Head and Neck Movement Animation

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Hip and Thigh Movement Animation

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Leg Movement Animation

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Trunk Movement Animation

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Figure 7.3Selected skeletal muscles (anterior view).




Figure 7.4Selected skeletal muscles and the Achilles tendon (posterior view).


• Smooth muscle– Also known as involuntary, visceral, or unstriated.– Not controlled by the conscious part of the brain.– Under the control of the autonomic nervous

system.– This type of muscle includes internal organs of the

digestive, respiratory, and urinary tract plus certain muscles of the eye and skin.


• Cardiac muscle– Muscle of the heart or myocardium is involuntary

but striated in appearance.– Controlled by the autonomic nervous system and

specialized neuromuscular tissue located within the right atrium.

Functions of Muscles

• Muscles are responsible for movement. The types of movement are:– Locomotion.– Propulsion of substances through tubes.– Changes in the size of openings as in the

contraction and relaxation of the iris of the eye.• Muscles also help maintain posture and

produce heat.

Contraction and Relaxation Animation

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Life Span Considerations:The Child

• At about 6 weeks, the embryo exhibits development of the skeletal and muscular systems.

• At 7 weeks, the diaphragm is completely developed.

• Muscular development proceeds from head to tail.

• Movement is uncoordinated and random.

Life Span Considerations:The Older Adult

• There is a decrease in muscle strength, endurance, range of motion, coordination, and flexibility of connective tissue.

• There is a loss in the number of muscle fibers.• Muscles need to be exercised regularly to

prevent loss of strength.

• Medical Words and Definitions with Word Parts.

• These terms (shown in black in the Building Your Medical Vocabulary feature) can be analyzed and defined by dividing them into component parts.

1. Prefixes (P)2. Roots (R)3. Combining Forms (CF)4. Suffixes (S)

Building Your Medical Vocabulary

• Medical Words and Definitions without Word Parts.• These terms (shown in pink in the Building Your Medical Vocabulary feature)

are not usually analyzed and defined by dividing them into component parts.

Building Your Medical Vocabulary




Figure 7.5Common sites of amputation. (A) Upper extremities. (B) Lower extremities. The surgeon determines the level of amputation based on blood supply and tissue

condition.




Figure 7.6Coordination of antagonist muscles to perform movement.




Figure 7.7Dupuytren’s contracture. (Courtesy of Jason L. Smith, MD.)




Figure 7.8Dermatomyositis. (Courtesy of Jason L. Smith, MD.)




Figure 7.9Diaphragm, the major muscle of breathing.




Figure 7.10Because the leg muscles of children with muscular dystrophy are weak, they must perform

the Gowers’ maneuver to rise to a standing position. (A) and (B) The child first maneuvers to a position supported by arms and legs. (C) The child next pushes off the floor and rests one

hand on the knee. (D) and (E) The child then pushes himself upright.

Lateral Position Video

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Prone Position Video

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Supine Position Video

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Fowler’s Position Video

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Sims’ Position Video

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Dorsal Recumbent Position Video

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Lithotomy Position Video

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Figure 7.11Total hip prosthesis.




Figure 7.12Giant cell tumor of tendon sheath. (Courtesy of Jason L. Smith, MD.)

Drug Highlights

• Skeletal Muscle Relaxants– Used to treat muscle spasms that may result from

strains, sprains, and musculoskeletal trauma or disease.

– These drugs act by depressing the CNS and can be administered either orally or by injection.

Drug Highlights

• Skeletal Muscle Stimulants– Used to treat myasthenia gravis.– Skeletal muscle stimulants act by inhibiting the

action of acetylcholinesterase, the enzyme that halts the action of acetylcholine at the neuromuscular junction.

Drug Highlights

• Neuromuscular Blocking Agents– Used to provide muscle relaxation during surgery,

electroconvulsive therapy, endotracheal intubation, and relieve laryngospasm.

Diagnostic and Lab Tests

• Aldolase (ALD) Blood Test– Test performed on serum that measures ALD

enzyme present in skeletal and heart muscle• Calcium Blood Test

– Test performed on serum to determine levels of calcium, which is essential for muscular contraction, nerve transmissions, and blood clotting


• Creatine kinase (CK)– A blood test to determine the level of CK– It is increased in necrosis or atrophy of skeletal

muscle, traumatic muscle injury, strenuous exercise, and progressive muscular dystrophy.

• Electromyography (EMG)– Test to measure electrical activity across muscle

membranes by means of electrodes that are attached to a needle that is inserted into the muscle.


• Lactic Dehydrogenase (LDH)– Blood test to determine the level of LDH enzyme

• Muscle Biopsy– Operative procedure in which a small piece of

muscle tissue is excised and then stained for microscopic examination


• Serum Glutamic Oxaloacetic Transaminase (SGOT)– Blood test to determine the level of SGOT enzyme– This test is also called asparate aminotransferase

(AST).• Serum Glutamic Pyruvic Transaminase (SGPT)

– Blood test to determine the level of SGPT enzyme– This test is also called alanine-aminotransferase

Atrophy

• Occurs with disuse of muscles over a long period of time. Atrophy can be caused by bed rest and immobility.

• When immobility is due to a treatment mode, such as casting or traction, one can decrease the effects of immobility by isometric exercise of the muscles of the immobilized part.

• Lipoatrophy is atrophy of fat tissue. It is also known as lipodystrophy.




Figure 7.13Lipoatrophy, wrist. (Courtesy of Jason L. Smith, MD.)

Atrophy Video

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Fibromyalgia

• Also known as fibromyalgia syndrome (FMS), fibromyalgia is a musculoskeletal pain and fatigue disorder.

• The exact cause of FMS is unknown, but is often traced to an injury or physical or emotional trauma.

• To be classified as an FMS patient, one must have at least 11 of 18 trigger points.




Figure 7.14The 18 tender points of fibromyalgia.

Myasthenia Gravis

• A chronic autoimmune neuromuscular disease characterized by varying degrees of weakness of the skeletal muscles of the body.

• The primary symptom of MG is muscle weakness that increases during periods of activity and improves after periods of rest.

Myasthenia Gravis

• It is caused by a defect in the transmission of nerve impulses to muscles.

• It occurs when normal communication between the nerve and the muscle is interrupted at the neuromuscular junction.

Myasthenia Gravis

• Treatment includes:– Lifestyle adjustments– Skeletal muscle stimulants

Muscular Dystrophy

• A group of genetic diseases characterized by progressive weakness and degeneration of the skeletal or voluntary muscles that control movement.

• There is no specific treatment, but physical therapy may be used to prevent contractures and orthoses.

• Corrective orthopedic surgery may be needed to improve the quality of life in some cases.

Muscular Dystrophy

• The major forms of MD include:– Myotonic (the most common form affecting

adults)– Duchenne (the most common form affecting

children)– Becker– Limb-Girdle– Facioscapulohumeral– Congenital– Oculopharyngeal– Distal– Emery-Dreifuss

Muscular Dystrophy Video

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Figure 7.15This young boy with muscular dystrophy needs to receive tube feedings and home

nursing care. He attends school when possible and is able to use an adapted computer.

medical terminology a word-building approach chapter 7 muscular system jane rice, rn, cma-c

Documents

striated muscle

types of muscle tissue

antagonist muscle

synergist muscle

basic types of muscle

living muscle cells

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jane rice slide