MOVESCI 110 Lecture Notes - Lecture 20: Vastus Lateralis Muscle, Triceps Brachii Muscle, Gastrocnemius Muscle
Document Summary
Functions of skeletal muscles: maintain body position (static, produce skeletal movement (dynamic, maintain body temp, support soft tissues (internal organs etc. , produce force. Types of muscle: smooth- involuntary, internal organs and blood vessels, cardiac- involuntary, skeletal- voluntary. Actin and myosin make the muscle shorter overall and contract to produce force. Contraction happens when the myosin attaches-moves-detaches from the actin (then repeat) Muscle contraction: muscle activation: action potential travels down the motor neuron to the muscle cell which starts the contraction. Range of motion: muscle rom: amount of travel in a contraction, joint rom: amount of movement around a joint. Force production: tension created by the muscle between two points when contracted (muscles can only produce tension force: origin: proximal attachment (least moveable, insertion: distal attachment (most moveable) Skeletal muscle structure: arrangement of fascicles has a large effect on the force and range of motion capability of the muscle: parallel, fusiform. Range of motion and speed are major functions: pennate.