Chapter 7 Muscular System

Learning Outcomes Describe the muscular system. Describe the three basic types of muscle tissue. Explain the primary functions of muscles. Analyze, build, spell, and pronounce medical words.

Learning Outcomes Describe diagnostic and laboratory tests related to the muscular system.

Anatomy and Physiology Overview The muscular system is composed of all the muscles in the body and works in coordination with the skeletal and nervous systems. Muscles Provide the mechanism for movement of the body. Produce heat. Help maintain posture and stability.

Anatomy and Physiology Overview Muscles make up approximately 42% of body weight. Muscles are composed of long, slender cells known as fibers. Each muscle consists of a group of fibers held together by connective tissue and enclosed in a fibrous sheath or fascia.

Figure 7.2 Types of muscle tissue.

Types of Muscles Cardiac muscle Muscle of the heart (myocardium) is involuntary but striated in appearance. Under control of the autonomic nervous system. Has specialized neuromuscular tissue located within the right atrium.

Types of Muscles Cardiac muscle Contraction can occur even without an initial nervous input because of pacemaker cells. Cardiac muscle cells rely on an ample blood supply to deliver oxygen and nutrients and to remove waste products, such as carbon dioxide.

Types of Muscles Smooth muscle Also called involuntary, visceral, or unstriated. Not controlled by the conscious part of the brain. Under the control of the autonomic nervous system. Includes muscles of internal organs of the digestive, respiratory, and urinary tract plus certain muscles of the eye and skin.

TABLE 7.1 Muscular System at-a-Glance 11

Types of Muscles Skeletal Muscle Also known as voluntary or striated muscle. Controlled by the conscious part of the brain and attaches to the bones. Has a cross-striped appearance (striated). Varies in size, shape, arrangement of fibers, and means of attachment to bones.

Types of Muscles Muscles have three distinguishable parts: the body or main portion. the origin (the more fixed attachment of the muscle to the stationary bone). the insertion (the point of attachment of a muscle to the bone that it moves).

Muscle Names Muscle location Muscle size Muscle purpose Muscle shape

http://www.getbodysmart.com/ap/muscularsystem/menu/menu.html Figure 7.3 Selected skeletal muscles and the Achilles tendon (anterior and posterior view).

Anatomy and Physiology Overview Each fiber within a muscle receives its own nerve impulses and has its own stored supply of glycogen as fuel for energy. Blood and lymphatic vessels in muscle tissue supply nutrition and oxygen to muscles.

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

Ligament – B2B Tendon – M2B

Functions of the Musculoskeletal System Tendons- Attach muscles to bones Ligaments – ligament/o Bands of connective tissue that connect bones, cartilages and other structures

Types of Muscles Means of attachment for skeletal muscle: Tendon (a band of connective tissue, varies in length from less than 1 inch to more than 1 foot) Aponeurosis (a wide, thin, sheetlike tendon)

Types of Muscles Muscles and nerves function together as a motor unit. Skeletal muscles perform in groups and are classified as follows: Prime mover/agonist is the prime muscle working in a particular exercise or movement. It’s this muscle that creates an action. Antagonist is the muscle that’s directly opposing the agonist muscle. As the agonist contracts, the antagonist relaxes. Synergist – is working together (aka, stablizers)

Pg 178 Agon/o Agony, a contest Path/o Disease Amputat/o To cut through Prosth/e An addition Brach/I Arm Rhabd/o Rod Cleid/o Clavicle Rotat/o To turn Clon/o Turmoil Sarc/o Flesh Ducto/o To lead Stern/o Sternum Dermat/o Skin Synov/o Synovial Fasci/o A band Ten/o Tendon Fibr/o Fiber Therm/o Hot, Heat Is/o Equal Ton/o Tone,Tension Muscul/o Muscle Tors/o Twisted My/o Tort/I Nuero/o nerve Volunt/o Will

How many words can we define? Myoblast Myorrhapy Myofibroma Myosarcoma Myograph Myoscelerosis Myokinesis Myositis Myoma Myotome Myomalacia Myotomy Myoparesis Neuromyopathic Myopathy Muscular Dystrophy Myoplasty