Author: Glossary

  • Laryngeal muscle

    Any of the six short muscles inside the larynx that move the vocal apparatus and (except for the cricothyroid muscle) are innervated by the recurrent laryngeal branch of the vagus nerve (CN X).  

  • Internal intercostal muscle

    The muscles between the ribs, lying beneath the external intercostals. During expiration, they pull the ribs downward and inward, decreasing the volume of the chest cavity and contributing to a forced exhalation.  

  • Iliacus muscle

    A muscle of the hip and thigh originating on the iliac fossa and inserted (with the psoas major, forming the iliopsoas) in the lesser trochanter of the femur. The psoas major and the iliacus flex and laterally rotate the thigh. If the thigh is fixed, the iliacus flexes the trunk at the hip. The iliacus…

  • Hyoglossus muscle

    A sheet of muscle extending up from the hyoid bone to the ipsilateral base and sides of the tongue. It depresses the sides of the tongue and is innervated by cranial nerve XII (hypoglossal nerve).  

  • Genioglossus muscle

    A fan-shaped extrinsic tongue muscle that makes up most of the volume of the tongue. The genioglossus originates from the inside of the anterior base of the mandible. Most of its muscle fibers attach broadly along the intrinsic tongue muscles of the top of the tongue. Some of the lower genioglossal fibers attach along the…

  • Gemellus muscle

    Either of the two muscles (gemelli muscles) that attach to the medial surface of the greater trochanter of the femur (i.e., the trochanteric fossa) where they mesh with the tendon of the obturator internus muscle. The superior gemellus muscle arises from the ischial spine and is innervated by the nerve to the obturator internus; the…

  • Flexor pollicis brevis muscle

    A muscle of the hand originating on the flexor retinaculum and trapezium, trapezoid, and capitate and inserted on the lateral side of the base of the first phalanx of the thumb. It flexes the thumb at both the carpometacarpal joint and the metacarpophalangeal joint and is controlled by the median and the ulnar nerves.  

  • Fixation muscle

    A muscle that steadies a part so that more precise movements in a related structure may be accomplished.  

  • Fibularis longus muscle

    A muscle along the outside of the leg that bends the foot outward at the ankle. The fibularis longus originates from the head and upper lateral surface of the fibular, runs in a bony groove along the bottom of the foot to attach on the other side at the base of the first metatarsal and…

  • External intercostal muscle

    The outer layer of muscles between the ribs, originating on the lower margin of each rib and inserted on the upper margin of the next rib. During inspiration, they draw adjacent ribs together, pulling them upward and outward, and increasing the volume of the chest cavity. They are controlled by the intercostal nerves.