click below
click below
Normal Size Small Size show me how
Muscular system Ch
Chapter 9 Q & A
Question | Answer |
---|---|
What are the 3 types of muscle? | Cardiac, smooth, and skeletal |
What are the general characteristics of cardiac muscle? | Found only in the heart; appear striated; consist of short, branching fibers at intercalated discs; involuntary muscle |
What are the general characteristics of smooth muscle? | Found in the digestive tract, blood vessels, bladder, airways, and uterus; nonstriated, involuntary muscle |
What are the general characteristics of skeletal muscle? | Attach to bone; cause movement of the body; markedly striated; voluntary muscle |
What are 2 ways skeletal muscle attaches to bone? | Direct attachment and indirect attachment |
What is direct attachment? | Muscle fibers merge with the periosteum of bone, forming a strong attachment |
What is indirect attachment? | The epimyseum extends past the muscle as a tendon. The tendon then merges with the periosteum |
What are the components of a muscle fiber? | Sarcolemma, sarcoplasm, myofibrils, sarcoplasmic reticulum, myofiliments, and transverse (T) tubules |
What is sarcolemma? | Plasma membrane surrounding each muscle fiber |
What is sarcoplasm? | Cytoplasm of the cell |
What are myofibrils? | Long protein bundles that store glycogen and oxygen |
What is sarcoplasmic reticulum? | (SR) Smooth endoplasmic reticulum of a muscle fiber that surrounds each myofibril and where calcium ions are stored |
What are myofilaments? | Fine fibers, either thick or thin, that give skeletal muscle its striated appearance |
What are transverse (T) tubules? | Formed from inward projections of the sarcolemma that extend across the sarcoplasm and allow electrical impulses to travel deep into the cell |
What is the difference between isometric and isotonic contractions? | In isometric contractions, tension within a muscle increases while it's length remains the same. In isotonic contractions, the muscle changes length while the tension remains the same |
How are muscles named? | According to their size, shape, location, number of origins, the direction of muscle fibers, or their action |
What is a rotator cuff injury? | The shoulder has a tendency toward injury. A fall, hard blow, or repetitive use can injure muscles. Overuse can also cause tendons to become inflamed. The tendon can degenerate and eventually rupture |
What is carpal tunnel syndrome? | Tendons as well as the median nerve pass through this channel. Repetitive flexion and extension of the wrist triggers inflammation and swelling in the sheath surrounding the tendons. The carpal tunnel can't expand, producing tingling, weakness, and pain |
How does endurance (aerobic) exercise affect muscles? | Trains muscles to resist fatigue. Does not significantly increase muscle strength. Exercise affects muscle fibers, strengthens bone, increases red blood cells, and enhances functions of the cardiovascular, respiratory, and nervous systems |
How does resistance exercise affect muscles? | Resistance exercise, such as lifting weights, increases muscles strength. A few minutes a day, several times a week, is enough to stimulate muscle growth |