Chapter 10 - Section 10.1 - Study Guide - Assess Your Learning Outcomes - Page 371: 11

Muscles are named using Latin or Latinized terms that describe location, shape, size, action, insertion/origin, direction of fibers and number of tendons of origin(heads). Feature: location--based on associated bone or body region. Examples: External intercostals muscles are outer muscles that are located between the ribs Temporalis muscle lies over the temporal bone Other examples: coracobrachialis and sternocleidomastoid. Feature: shape: Examples: Trapezius muscle. Both muscles together resemble a trapezoid--a quadrilateral with one pair of parallel sides. Deltoid. A muscle that has the shape of the greek letter delta Teres major. Teres means round, smooth or cylindrical Feature: Orientation of fibers/fascicles Examples: Rectus abdominis. Rectus means straight. These muscle are commonly referred to by athletes as "abs" or "six packs." The fibers run vertically on each side of the linea alba in humans. External oblique abdominis. These muscles are superficial to the internal obliques. Their fiber run obliquely ( diagonally) across the side of the abdomen.

Feature Action or function: Flexing: Narrows the joint angle Examples: Flexor hallucis longus: long muscle that flexes the big toe. Depressor labii inferioris: muscle that lowers the bottom lip. Extensor carpi radialis longus: long muscle that starts on the humerus, runs along the radius to the wrist, and inserts on the second metacarpal. It extends the hand at the wrist. Abductor pollicis longus. A long muscle that moves the thumb away from the midline at the carpometacarpal joint. The muscle used to signal "thumbs up." Adductor magnus: large muscle that adducts ( and medially rotates) the thigh at the hip. Feature: Size terms-- magnus, vastus, major, minimi/minimis, minor, longus, brevis. Magnus means large;,vastus means very large; maximus means largest; longus means long; brevis means short; major means larger; minor means smaller. Examples: Gluteus maximus Adductor magnus Vastus lateralis Gluteus minimus Flexor digiti minimi Flexor digitorum longus Flexor digitorum brevis Pectoralis major Teres minor Feature: Position Superioris means( upper); inferioris mean ( lower). Supra means above ;infra means below; lateralis means to the side, and medialis means nearer the midline. Examples : Supraspinatus Infraspinatus Levator palpebrae superioris Depressor labii inferioris Vastus lateralis Vastus medialis Feature : Number of origins/heads Biceps means two heads ; triceps means three heads, and quadriceps means four heads Examples; Biceps femoris Triceps brachii Quadriceps femoris