Muscle tables

Muscle tables - PSIO 201 Required Handout Department of...

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PSIO 201 Required Handout Department of Physiology Naming skeletal muscles Early anatomists named skeletal muscles based on a number of different characteristics. These characteristics include muscle shape, size, number of origins, action, location, and the direction in which the muscle fibers run. TABLE 1: Naming skeletal muscles Characteristic Description Example Direction of muscle fibers Rectus: Fibers run parallel to the midline Transverse: Fibers run perpendicular to the midline Oblique: Fibers run diagonal to the midline Rectus abdominis Transverse abdominis External oblique Size Maximus: Largest Minimus: Smallest Longus: Longest Gluteus maximus Gluteus minimus Adductor longus Location Named for the bone(s) to which the muscle attaches, or region within which the muscle is found. Tibialis anterior Occipitalis Sternocleidomastoid Shape Deltoid: Triangular shape Rhomboid: Diamond shape Trapezius: Trapezoid shape Deltoid Rhomboid major Trapezius Number of origins Biceps: Two origins Triceps: Three origins Quadriceps: Four origins Biceps femoris Triceps brachii Quadriceps femoris Action Named for the action that the muscle performs. Adductor magnus Levator scapulae TABLE 2: Muscles of the face, head, and neck Muscle Location* Action Occipitofrontalis: Frontalis and Occipitalis Composite muscle that overlies the cranium; the two muscles are connected by an aponeurosis. Frontalis: Raises the eyebrows Occipitalis: Draws scalp posteriorly Orbicularis oris Circular muscle that encircles the mouth. Puckers the mouth as in kissing. Orbicularis oculi Circular muscle that encircles each eye. Closes each eye as in blinking. Zygomaticus major Originates on the zygomatic bone and inserts on the skin at the corners of the mouth. Pulls the corners of the mouth superiorly as in smiling. Platysma Originates on the fascia of the chest and deltoid and inserts on the mandible and skin below the mouth. Depresses the lower lip and mandible; tenses neck skin. Temporalis Originates on the temporal bone and inserts on the mandible. Elevates and retracts the mandible. Masseter Originates on the maxillae and zygomatic bones and inserts on the mandible. Elevates and protracts the mandible. Sternocleidomastoid Originates on the sternum and clavicle and inserts on the mastoid process of the temporal bone. If one side contracts, the head rotates to the opposite side. If both contract, flexion of the head is the result. *Students will NOT be tested on the specific origins and insertions
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PSIO 201 Required Handout Department of Physiology Muscles that move the vertebral column Contraction of the muscles of the anterior and posterior trunk creates movement of the vertebral column. Abdominal muscles located on the anterior trunk include the rectus abdominis , external oblique , internal oblique , and transverse abdominis . The most superficial of these muscles, the rectus abdominis, often appears to have six different portions in lean individuals. This appearance is due to the presence of
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Muscle tables - PSIO 201 Required Handout Department of...

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