Handout sa Anaphy, BIONeers ,,eto na po ... Camarines Norte State College College of Education GROSS ANATOMY OF SKELETAL MUSCLE Discussant: Rachel R. Fortunado Head Muscle - It is grouped into two categories: o Facial Muscles- inserted into soft tissues such as other muscles or skin o Chewing Muscles- begin the breakdown of food for the body Facial Mucles 1. Frontalis- it allows to raise eyebrows, as in surprise, to wrinkle the forehead. 2. Orbicularis Oculi- It allows us to close our eyes, blink and wink. 3. Orbicularis oris- circular muscle of the lips. It is often called the “kissing muscle”. It closes the mouth and protrudes the lips. 4. Buccinator- it is the muscle that flattens the cheek when we do whistling or blowing a trumpet. 5. Zygomaticus- also called the “smiling muscle because it raises the corners of the mouth upward. Chewing Muscles 1. Masseter- covers the angle of the lower jaw. It closes the jaw by elevating the mandible. 2. Temporalis- a fan-shaped muscle overlying the temporal bone. it acts as a synergist of the masseter in closing the jaw. Trunk and Neck Muscles • Anterior Muscles o Platysma- a single sheet like muscle that covers the anterolateral neck. Its action is to pull the corners of the mouth inferiorly, producing downward sag of the mouth. o Sternocleidomastoid- are two headed muscles, one found on each side of the neck. Also called the “prayer muscles”. o Pectoralis major- large fan-shaped muscle that covers the upper part of the chest. Muscles of the Abdominal Girdle o Rectus abdominis- superficial muscles of thr abdomen that flexes the vertebral column. o External oblique- muscles that make up the lateral walls of the abdomen. It rotates the trunk and bend it laterally. o Internal oblique- paired muscles deep into the external obliques. Their function is the same as those of external obliques. o Transverses abdominis- the deepest muscle of the abdominal wall and it compresses the abdominal contents. Posterior Muscles o Trapezius- form diamond or kite shaped muscle mass. It elevates, adducts, depress and stabilize the scapula. o Latissimus dorsi- large, flat muscle pair that covers the lower back. These are very important muscles when the arm must be brought down in a power stoke, as when swimming or striking a blow. o Deltoid- fleshy, triangle-shaped muscle that forms rounded shape in the shoulders. It is also the favorite site of injection because of its bulkiness. Muscles of the Humerus that Act on the Forearm o Biceps brachii- the powerful prime mover for flexion of the forearm and acts to supinate the forearm. o Triceps brachii- often called the boxer’s muscle because it can deliver a straight-arm knockout punch. Muscles Causing Movement of the Hip Joint o Gluteus maximus- muscle that forms most of the flesh of the buttock. It is important in extending the hip when power is needed. o Gluteus medius- it is a hip abductor and important in steadying the pelvis during walking and an important site for giving intramuscular injections. o Iliopsoas- it acts to keep the upper body from falling backward when we are standing eract. Muscle Causing Movement of Ankle and Foot o Peroneus- flexes and everts the foot o Gastrocnemius- two-bellied muscle that forms the curved calf of the posterior leg. Also called “toe dancer’s muscle” for it is a prime mover for plantar flexion of the foot.
Posted on: Mon, 19 Aug 2013 08:19:11 +0000