Muscular System Objectives: TSWBAT : Identify the three types of muscle tissue and its components. Identify the six functions of the muscular system. Label the major muscles in the human body. Analyze the movements of the joints and what muscles create the movements. Explain common injuries and medical conditions of the muscular system.

 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

Muscle plays six important roles in the body: 1. Produce skeletal movement 2. Maintains posture and body position 3. Support soft tissues (abdominal wall & pelvic cavity) 4. Guard entrances and exits (digestive and urinary tracts) 5. Maintain body temperature (energy is converted to heat) 6. Store nutrient reserves (proteins are broken down & amino acids are used)

1. Skeletal 2. Cardiac 3. Smooth

 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

Three layers of connective tissue are part of each muscle: 1. Epimysium – dense layer of collagen fibers that surround the entire muscle 2. Perimysium – divides the muscle into a series of compartments each containing a bundle of muscle fibers (fascicle); contains collagen & elastic fibers, blood vessels and nerves that maintain blood flow 3. Endomysium – flexible, elastic connective tissue layer; surrounds the individual skeletal muscle cells and interconnects adjacent muscle fibers

 The muscle fibers in a single fascicle are parallel, but the organization of fascicles in skeletal muscles can vary  The arrangement is correlated with muscle power and range of motion (structure determines function)  Skeletal muscles are classified as: 1. Parallel muscles (most common) – fascicles are parallel to the long axis of the muscle 2. Convergent muscles – converge at a common attachment site; fibers spread out and pull in different directions 3. Pennate muscles – form a common angle with the tendon 4. Circular muscles – cocentrically arranged around an opening

 At the end of the muscle, the collagen fibers of the epimysium, perimysium, and endomysium come together to form a tendon or aponeurosis  Tendons and aponeuroses 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

 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

Naming of Skeletal Muscles Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Direction of muscle fibers Example: rectus (straight)  Relative size of the muscle Example: maximus (largest)

Naming of Skeletal Muscles Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Location of the muscle Example: many muscles are named for bones (e.g., temporalis)  Number of origins Example: triceps (three heads)

Naming of Skeletal Muscles Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Location of the muscles origin and insertion Example: sterno (on the sternum)  Shape of the muscle Example: deltoid (triangular)  Action of the muscle Example: flexor and extensor

 Axial muscles arise on the axial skeleton (60% of skeletal muscles) ; position the head and spinal column and move the rib cage  Appendicular muscles stabilize and move the appendicular skeleton (40% of skeletal muscles)

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

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

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

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

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

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

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

 Agonist (prime mover) – a muscle whose contraction is mostly responsible for producing a particular movement Example – biceps brachii  Antagonist – a muscle whose action opposes that of a particular agonist Example – triceps brachii  Agonists and antagonists are functional opposites  Synergists – help a larger agonist work efficiently

 Muscle Tone – resting tension in a skeletal muscle  Isotonic muscle contraction – tension rises and the skeletal muscle’s length changes (lifting)  Isometric muscle contraction – the muscle as a whole does not change length, and the tension produced never exceeds the load (holding)

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

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

 Dorsiflexion  Plantar flexion Special Movements

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Inversion  Eversion

 Opposition  Supination  Pronation

 Choose a sport or activity where movement is involved (football, yoga, softball, swimming, skate boarding, etc.)  Write a short story about the sport/activity (choose a competition, game, or practice)  Include 10 muscles and 5 movements in the story that the participant(s) demonstrates  Circle the muscle names & underline the movements in your story  You must include one picture with your story  Use the “arts and supplies” to complete your final draft  The story is a classwork grade of 20 points (1 point for each required term and 5 points for your picture/creativity)

 TSWBAT identify injuries of the muscular system.  TSWBAT compare a strain and sprain.  TSWBAT list the elements of RICE for first aid of muscular system injuries.

What is a strain? Strains are injuries that involve the stretching or tearing of a musculo-tendinous (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) Strain vs. Sprain

Ankle Sprains

Examples of Strains

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 (ice)  C - compression  E - elevation

Duchenne Muscular Dystrophy (DMD) Definition - One of nine types of muscular dystrophy, 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:

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.  Hayy4I

 Most surgery for ACL injuries involves replacing the ACL with tissue called a graft  Usually an autograft (tendon taken from another part of the body) is used  The most common grafts used are the tendon of the kneecap or one of the hamstring tendons  Another choice is allograft tissue, which is taken from a deceased donor

 Repairs an injured elbow ligament (UCL construction)  A surgeon replaces the injured UCL with a tendon taken from somewhere else in the patient’s body

 Loss of muscle function in part of your body  Occurs when something goes wrong with the way messages pass between your brain and muscles  Can be complete or partial; occur on one or both sides of your body; one area or widespread  Paraplegia: lower half of your body  Quadriplegia: arms and legs  Due to strokes, injuries (spinal cord), or a broken neck