Chapter 11 - The Muscular System - Figure 11.3 - Page 336: 1

Examples of muscles names based on selected characteristics: 1. Direction of fibers: Rectus abdominis External oblique Transversus abdominis 2.Shape of muscle: Deltoid Trapezius Obicularis oris 3. Action Flexor carpi radialis Extensor carpi ulnaris Adductor longus 4. Size Gluteus maximus Pectoralis major Adductor brevis 5. Number of origins(tendons) Biceps brachii Triceps brachii Triceps femoris 6. Origin and insertion Strnocleidomastoid 7. Location Temporalis

Rectus means straight and the fascicles of the rectus abdominis run parallel to the midline of the body, that is straight up and down. contraction of the rectus abdominis ( the abs) flexes the trunk The deltoid muscle, as the name implies, has a triangular shape, and the obicularis ( circle ) oris (mouth) surrounds the mouth. Extensors increase joint angles and flexor muscles decrease joint angles. The flexor carpi radialis flexes the hand at the wrist joint, but the extensor carpi ulnaris extends the hand at the wrist joint.. Maximus means largest and the gluteus maximus ( rump or buttocks) is the largest of the three gluteal muscles-- gluteus maximus, gluteus medius , and gluteus minimus. The biceps brachii has two origins, and the triceps brachii has three. They flex and extend the fore arm at the elbow joint, respectively. The sternocleidomastoid is so named because its origin is in the sternum (manubrium) and the clavicle. The mastoid part of the name derives from its insertion on the mastoid process of the temporal bone. The temporalis muscle is so named because of it location in the temporalis fossa of the temporal bone. It is a broad muscle important for chewing.