Objective: Muscular System
1. Three types of muscles are the stapedius, latissimus dorsi, and the deltoid muscle. The smallest stapedius muscle is the smallest muscle which measures 1/20th of an inch. It is the activator of the stirrup that sends vibrations from the eardrum to the inner ear. The largest muscle is the latissimus dorsi. This muscle is the flatest muscle of the back that moves during arm movement. The deltoid muscle is a triangular shaped muscle of the shoulder that forms the rounded flesh of the outer part of the upper arm.
2. The mechanism of muscle contraction is the sacromere. Actin filaments are anchored in their midpoints called a Z line; a sacromere is the region from on Z line to the next. When a muscle contracts myosin filaments and actin filaments interact to shorten the length of a sacromere.
3. Flexors and Extensors are muscles. A flexor is a muscle that bends at a joint, like the biceps. An extensor is a muscle that straightens a joint, like the triceps.
4. Muscle fatigue is the physiological inability of a muscle to contract. When energy availability fails to keep pace with its use, muscle fatigue sets in and controlled muscle activity ceases, even though the muscle may still receive stimulation to move
5. Muscles, bones and tendons are all related. Most of the time, skeletal muscles are attached to one end of a bone, stretched across a joint, and attached to another bone. Muscles are attached to the outer membrane of the bone by tendons, or tough connective tissue.
6. The all-or-none response is muscle contraction. Either the fiber contract of they remains relaxed. The number of muscle fibers stimulated results in the force of the muscle contraction.
7. 10 major muscles of the body are: