Chapter 5 Muscular System

MUSCLES Approximately 40% of your body weight Approximately 650 muscles Muscles only pull (they can’t push) You have over 30 facial muscles Eye muscles move more than 100,000 times a day

There are 3 types of muscle tissue Skeletal Cardiac Smooth

Skeletal Muscles Definition - organs that are composed mainly of skeletal muscle tissue, but they also contain connective tissues, nerves, and blood vessels. Each cell is a single muscle fiber. Muscle fibers form bundles called fascicles. Directly or indirectly attached to the bones of the skeleton

Skeletal Muscle Functions Muscle plays six important roles in the body: Produce skeletal movement Maintains posture and body position Support soft tissues (abdominal wall & pelvic cavity) Guard entrances and exits (digestive and urinary tracts) Maintain body temperature (energy is converted to heat) Store nutrient reserves (proteins are broken down & amino acids are used)

Organization of Skeletal Muscle Tissue At the end of the muscle, the collagen fibers come together to form a tendon. Tendons attach muscles to bone Origin – where the fixed end of the muscle attaches to the bone (cartilage or connective tissue) Insertion – where the movable end of the muscle attaches to another structure

Origin/Insertion Example Gastrocnemius – calf muscle that extends from the distal portion of the femur to the calcaneus When it contracts it pulls the calcaneus toward the knee Origin – femur Insertion - calcaneus

Head and Neck Muscles Figure 6.14 Slide 6.38 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Trunk Muscles Figure 6.15 Slide 6.39 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Deep Trunk and Arm Muscles Figure 6.16 Slide 6.40 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Muscles of the Pelvis, Hip, and Thigh Figure 6.18c Slide 6.41 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Muscles of the Lower Leg Figure 6.19 Slide 6.42 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Superficial Muscles: Anterior Figure 6.20 Slide 6.43 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Superficial Muscles: Posterior Figure 6.21 Slide 6.44 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Types of Ordinary Body Movements Flexion – bending at the joint Extension - straightening at the joint Hyperextension Rotation – rotating on axis Abduction – moving away from the midline Adduction – moving toward the body Circumduction – circular movement Slide 6.32 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Body Movements Figure 6.13 Slide 6.33 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Special Movements Dorsifelxion Plantar flexion

Special Movements Inversion Eversion Slide 6.34 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

STRETCHING!! Lactic Acid- Toxins that build up within our muscles due to: Over working the muscles Damaging the muscles Not receiving enough oxygen Two kinds of stretching: 1. Static 2. Dynamic

Strain vs. Sprain What is a strain? Strains are injuries that involve the stretching or tearing of a (muscle and tendon) structure What is a sprain? A sprain is an injury involving the stretching or tearing of a ligament (tissue that connects bone to bone)

Ankle Sprains

Examples of Strains

Sprains and Strains are categorized according to severity. Grade I (mild) sprain or strain involves some stretching or minor tearing of a ligament or muscle. Grade II (moderate) sprain or strain is a ligament or muscle that is partially torn but still intact. Grade III (severe) sprain or strain means that the ligament or muscle is completely torn, resulting in joint instability.

R – rest I - immobilize Braces and Ice (20 min.) C - compression First Aid R – rest I - immobilize Braces and Ice (20 min.) C - compression E - elevation

Rebuilding Muscles Protein builds AMINO ACIDS to repair and build muscles. Muscle Atrophy- Muscle Hypertrophy-

ACL (Connects femur to tibia)

ACL Tear (Signs and Symptoms) Feeling or hearing a pop in the knee at the time of injury. Pain on the outside and back of the knee. The knee swelling within the first few hours of the injury. Limited knee movement because of pain, swelling or both. The knee feeling unstable, buckling or giving out

Contusions

Muscle Cramping A muscle cramp is an involuntarily and forcibly contracted muscle that does not relax. Almost everyone experiences a muscle cramp at some time in their life. Numerous medicines can cause muscle cramps. Most muscle cramps can be stopped if the muscle can be stretched. Prevent by drinking plenty of water before, during and after exercising!!

Compartment Syndrome is a painful condition that occurs when pressure within the muscles builds to dangerous levels. This pressure can decrease blood flow, which prevents nourishment and oxygen from reaching nerve and muscle cells. Symptoms: Aching, burning or cramping Tightness Numbness or tingling Weakness

Why do we need to rehab an injury? Can muscle soreness be good?

Information obtained from: http://www.mda.org/disease/dmd.html Muscular Dystrophy Definition - a group of genetic, degenerative diseases primarily affecting voluntary muscles. Cause - An absence of dystrophin, a protein that helps keep muscle cells intact. Information obtained from: http://www.mda.org/disease/dmd.html

DMD continued..... http://www.youtube.com/watch?v=_ZAOOHayy4I Onset - Early childhood - about 2 to 6 years. Symptoms - Generalized weakness first affecting the muscles of the hips, pelvic area, thighs and shoulders. Calves are often enlarged. Progression - DMD eventually affects all voluntary muscles, and the heart and breathing muscles. Inheritance - X-linked recessive. DMD primarily affects boys, who inherit the disease through their mothers. Women can be carriers of DMD but usually exhibit no symptoms. http://www.youtube.com/watch?v=_ZAOOHayy4I