The Muscular System Lesson 1: The Muscular System

The Muscular The Muscular SystemSystemLesson 1:Lesson 1:The Muscular SystemThe Muscular System

Upon completion of this lesson, students should be able to …

Explain the functions of muscle. Identify and discuss types of muscle tissue. Describe the muscular system of the body.

Bundles of muscle fibersFibers contract; Muscles contractmyoneural junction

Human has more than 600 muscles

Muscles make up about 42% of body weight

Contractibility

Heat production

Stability

Tonicity

the body can move voluntary, striated muscles.

Attach to skeletal bones Allow for voluntary movement Wrapped in layers

◦Fascia◦Tendon attach muscle to bone

motor neurons

muscle that pumps blood to involuntary muscle.

Myocardium Occurs in walls of heart Allows for involuntary pumping action

involuntary nonstriated continuous, thin layer forming organs and other structures.

Found in tissue in walls of hollow organs

Responsible for movement of internal organs

2 types◦Voluntary: Allows the person to dictate movement

◦Involuntary: Acts without conscious direction

Type of chemical energy needed for muscular contractions either aerobic or anaerobic (without

oxygen) means

Occurs when skeletal muscles are used for more than 1 or 2 minutes

Lack of oxygen reduces body’s ability to produce energy

Oxygen “owed” to body is the debt can only be recovered by increased respiration

accumulated lactic acid decreases the ability to contract results in fatigue, crampsalso occurs if blood supply is interrupted

Fascia◦Covers entire skeletal muscle◦Separates muscles from one another

Muscles of the jaw (chewing):

Deltoid – abduction/extension of the arm at the shoulder

Common place for IM injections

Right now

Diaphragm◦ Separates thoracic and abdominal cavities

External and internal intercostals

External and internal obliques

Transversus abdominis Rectus abdominis

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Gluteus medius – aka the anterior gluteal site

Vastus lateralis – extends knee

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