{"id":2086,"date":"2014-10-28T21:40:01","date_gmt":"2014-10-28T21:40:01","guid":{"rendered":"https:\/\/courses.candelalearning.com\/apvccs\/?post_type=chapter&#038;p=2086"},"modified":"2016-10-20T15:54:34","modified_gmt":"2016-10-20T15:54:34","slug":"axial-muscles-of-the-head-neck-and-back","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/suny-mcc-ap1\/chapter\/axial-muscles-of-the-head-neck-and-back\/","title":{"raw":"Axial Muscles of the Head, Neck, and Back","rendered":"Axial Muscles of the Head, Neck, and Back"},"content":{"raw":"<div title=\"11.3.\u00a0Axial Muscles of the Head, Neck, and Back\" xml:lang=\"en\">\r\n<div>\r\n<div>\r\n<div class=\"bcc-box bcc-highlight\">\r\n<h3>Learning Objectives<\/h3>\r\n<ul>\r\n \t<li>Identify the axial muscles of the face, head, and neck<\/li>\r\n \t<li>Identify the movement and function of the face, head, and neck muscles<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<div>\r\n<ul>\r\n \t<li><a href=\"#m46484-fs-id1637749\">Muscles That Create Facial Expression<\/a><\/li>\r\n \t<li><a href=\"#m46484-fs-id2921724\">Muscles That Move the Eyes<\/a><\/li>\r\n \t<li><a href=\"#m46484-fs-id2518486\">Muscles That Move the Lower Jaw<\/a><\/li>\r\n \t<li><a href=\"#m46484-fs-id2777277\">Muscles That Move the Tongue<\/a><\/li>\r\n \t<li><a href=\"#m46484-fs-id1962667\">Muscles of the Anterior Neck<\/a><\/li>\r\n \t<li><a href=\"#m46484-fs-id2468950\">Muscles That Move the Head<\/a><\/li>\r\n \t<li><a href=\"#m46484-fs-id2009136\">Muscles of the Posterior Neck and the Back<\/a><\/li>\r\n<\/ul>\r\n<\/div>\r\nThe skeletal muscles are divided into\u00a0<strong><em>axial<\/em><\/strong><a id=\"id710578\"><\/a>\u00a0(muscles of the trunk and head) and\u00a0<strong><em>appendicular<\/em><\/strong><a id=\"id710592\"><\/a>\u00a0(muscles of the arms and legs) categories. This system reflects the bones of the skeleton system, which are also arranged in this manner. The axial muscles are grouped based on location, function, or both. Some of the axial muscles may seem to blur the boundaries because they cross over to the appendicular skeleton. The first grouping of the axial muscles you will review includes the muscles of the head and neck, then you will review the muscles of the vertebral column, and finally you will review the oblique and rectus muscles.\r\n<div title=\"Muscles That Create Facial Expression\">\r\n<div>\r\n<h3 id=\"m46484-fs-id1637749\">Muscles That Create Facial Expression<\/h3>\r\n<\/div>\r\nThe origins of the muscles of facial expression are on the surface of the skull (remember, the origin of a muscle does not move). The insertions of these muscles have fibers intertwined with connective tissue and the dermis of the skin. Because the muscles insert in the skin rather than on bone, when they contract, the skin moves to create facial expression (Figure\u00a011.7).\r\n<div id=\"m46484-fig-ch11_03_01\" title=\"Figure\u00a011.7.\u00a0Muscles of Facial Expression\">\r\n<div>\r\n<div><img src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181708\/1106_Front_and_Side_Views_of_the_Muscles_of_Facial_Expressions.jpg\" alt=\"The left panel in this figure shows the anterior view of the facial muscles, and the right panel shows the lateral view.\" width=\"520\" \/><\/div>\r\n<\/div>\r\n<address><strong>Figure\u00a011.7.\u00a0Muscles of Facial Expression<\/strong><\/address><address>Many of the muscles of facial expression insert into the skin surrounding the eyelids, nose and mouth, producing facial expressions by moving the skin rather than bones.<\/address><address>\u00a0<\/address><\/div>\r\nThe\u00a0<strong><em>orbicularis oris<\/em><\/strong><a id=\"id710677\"><\/a>\u00a0is a circular muscle that moves the lips, and the\u00a0<strong><em>orbicularis oculi<\/em><\/strong><a id=\"id710690\"><\/a>\u00a0is a circular muscle that closes the eye. The\u00a0<strong><em>occipitofrontalis<\/em><\/strong><a id=\"id710704\"><\/a>\u00a0muscle moves up the scalp and eyebrows. The muscle has a frontal belly and an occipital (near the occipital bone on the posterior part of the skull) belly. In other words, there is a muscle on the forehead (<em><strong>frontalis<\/strong><\/em><a id=\"id710719\"><\/a>) and one on the back of the head (<em><strong>occipitalis<\/strong><\/em><a id=\"id710732\"><\/a>), but there is no muscle across the top of the head. Instead, the two bellies are connected by a broad tendon called the\u00a0<strong><em>epicranial aponeurosis<\/em><\/strong><a id=\"id710746\"><\/a>, or galea aponeurosis (galea = \u201capple\u201d). The physicians originally studying human anatomy thought the skull looked like an apple.\r\n\r\nThe majority of the face is composed of the\u00a0<strong><em>buccinator<\/em><\/strong><a id=\"id710769\"><\/a>\u00a0muscle, which compresses the cheek. This muscle allows you to whistle, blow, and suck; and it contributes to the action of chewing. There are several small facial muscles, one of which is the\u00a0<strong><em>corrugator supercilii<\/em><\/strong><a id=\"id710784\"><\/a>, which is the prime mover of the eyebrows. Place your finger on your eyebrows at the point of the bridge of the nose. Raise your eyebrows as if you were surprised and lower your eyebrows as if you were frowning. With these movements, you can feel the action of the corrugator supercilli. Additional muscles of facial expression are presented in\u00a0Figure\u00a011.8.\r\n<div id=\"m46484-fig-ch11_03_02\" title=\"Figure\u00a011.8.\u00a0Muscles in Facial Expression\">\r\n<div>\r\n<div><img src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181710\/1125_Muscles_in_Facial_Expression.jpg\" alt=\"This table describes the muscles used in facial expressions. To furrow the brow, the skin of the scalp moves in an anterior direction. The prime mover is the occipitofrontalis frontal belly, which originates from the epicraneal aponeurosis and inserts underneath the skin of the forehead. To unfurrow the brow, the skin of the scalp moves in the posterior direction. The prime mover is the occipitofrontalis occipital belly, which originates from the occipital bone and the mastoid process of the temporal bone and inserts into the epicraneal aponeurosis. To lower the eyebrows, as when scowling or frowning, the skin underneath the eyebrows moves in an inferior direction. The prime mover is the corrugator supercilii, which originates from the frontal bone and inserts into the skin underneath the eyebrow. To flare the nostrils, the nasal cartilage is compressed in an inferior and posterior direction. The prime mover is the nasalis, which originates from the maxilla and inserts into the nasal bone. Raising the upper lip involves elevating the upper lip tissue. The prime mover is the levator labii superioris, which originates from the maxilla and inserts underneath the skin at the corners of the mouth and also into the orbicularis oris. Lowering the lower lip involves depressing the lip and also moving it laterally. The prime mover is the depressor angulus oris, which originates from the mandible and inserts underneath the skin of the lower lip. Opening the mouth and sliding the lower jaw left and right involves depressing the lower jaw and also moving it laterally. The prime mover is thecdepressor angulus oris, which originates from the mandible and inserts underneath the skin at the corners of the mouth. Smiling involves elevating the corners of the mouth and also moving them in a lateral direction. The prime mover is the zygomaticus major, which originates from the zygomatic bone and inserts underneath the skin at the corners of the mouth in the dimple area, and also into the orbicularis oris. Shaping of the lips as during speech involves moving the lips in multiple directions. The prime mover is the orbicularis oris which originates from the tissue surrounding the lips and inserts underneath the skin at the corners of the mouth. Lateral movement of the cheeks such as when sucking on a straw or to compress air in the mouth while blowing involves moving the cheeks in a lateral direction. The prime mover is the buccinator, which originates from the maxilla, the mandible, and the sphenoid bone via the pterygomandibular raphae, and inserts into the orbicularis oris. Pursing of the lips by straightening them laterally involves moving the corners of the mouth in a lateral direction. The prime mover is the risorius, which originates from the fascia of the parotid salivary gland and inserts underneath the skin at the corners of the mouth. Protrusion of the lower lip, as when making a pouting expression, involves protracting the lower lip and the skin of the chin. The prime mover is the mentalis, which originates from the mandible and inserts underneath the skin of the chin. Raising the upper lip involves elevating the upper lip. The prime mover is the levator labii superioris, which originates from the maxilla and inserts underneath the skin at the corners of the mouth and also into the orbicularis oris.\" width=\"520\" \/><\/div>\r\n<\/div>\r\n<address><strong>Figure\u00a011.8.\u00a0Muscles in Facial Expression<\/strong><\/address><address>\u00a0<\/address><\/div>\r\n<\/div>\r\n<div title=\"Muscles That Move the Eyes\">\r\n<div>\r\n<h3 id=\"m46484-fs-id2921724\">Muscles That Move the Eyes<\/h3>\r\n<\/div>\r\nThe movement of the eyeball is under the control of the\u00a0<strong><em>extrinsic eye muscles<\/em><\/strong><a id=\"id710909\"><\/a>, which originate outside the eye and insert onto the outer surface of the white of the eye. These muscles are located inside the eye socket and cannot be seen on any part of the visible eyeball (Figure\u00a011.9\u00a0and\u00a0Table\u00a011.3). If you have ever been to a doctor who held up a finger and asked you to follow it up, down, and to both sides, he or she is checking to make sure your eye muscles are acting in a coordinated pattern.\r\n<div id=\"m46484-fig-ch11_03_03\" title=\"Figure\u00a011.9.\u00a0Muscles of the Eyes\">\r\n<div>\r\n<div><img src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181714\/1107_The_Extrinsic_Eye_Muscles.jpg\" alt=\"The left panel shows the lateral view of the muscles for the right eye, and the right panel shows the anterior view of the muscles for the right eye.\" width=\"525\" \/><\/div>\r\n<\/div>\r\n<address><strong>Figure\u00a011.9.\u00a0Muscles of the Eyes<\/strong><\/address><address>(a) The extrinsic eye muscles originate outside of the eye on the skull. (b) Each muscle inserts onto the eyeball.<\/address><address>\u00a0<\/address><address><a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090343\/Screen-Shot-2014-11-12-at-9.38.02-PM.png\"><img class=\"alignnone wp-image-2440 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090343\/Screen-Shot-2014-11-12-at-9.38.02-PM.png\" alt=\"Screen Shot 2014-11-12 at 9.38.02 PM\" width=\"650\" height=\"559\" \/><\/a>\u00a0<\/address><address>\u00a0 \u00a0\u00a0<a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090342\/Screen-Shot-2014-11-12-at-9.38.18-PM.png\"><img class=\"alignnone wp-image-2439 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090342\/Screen-Shot-2014-11-12-at-9.38.18-PM.png\" alt=\"Screen Shot 2014-11-12 at 9.38.18 PM\" width=\"630\" height=\"95\" \/><\/a><\/address><\/div>\r\n<div><\/div>\r\n<h3 id=\"m46484-tbl-ch11_03\">Muscles That Move the Lower Jaw<\/h3>\r\n<\/div>\r\n<div title=\"Muscles That Move the Lower Jaw\">\r\n\r\nIn anatomical terminology, chewing is called\u00a0<strong><em>mastication<\/em><\/strong>. Muscles involved in chewing must be able to exert enough pressure to bite through and then chew food before it is swallowed (Figure\u00a011.10\u00a0and\u00a0Table\u00a011.4). The\u00a0<strong><em>masseter<\/em><\/strong>\u00a0muscle is the main muscle used for chewing because it elevates the mandible (lower jaw) to close the mouth, and it is assisted by the\u00a0<strong><em>temporalis<\/em><\/strong>\u00a0muscle, which retracts the mandible. You can feel the temporalis move by putting your fingers to your temple as you chew.\r\n<div id=\"m46484-fig-ch11_03_04\" title=\"Figure\u00a011.10.\u00a0Muscles That Move the Lower Jaw\">\r\n<div>\r\n<div><img src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181718\/1108_Muscle_that_Move_the_Lower_Jaw.jpg\" alt=\"The left panel of this figure shows the superficial chewing muscles in face, and the right panel shows the deep chewing muscles.\" width=\"485\" \/><\/div>\r\n<\/div>\r\n<address><strong>Figure\u00a011.10.\u00a0Muscles That Move the Lower Jaw<\/strong><\/address><address>The muscles that move the lower jaw are typically located within the cheek and originate from processes in the skull. This provides the jaw muscles with the large amount of leverage needed for chewing.<\/address><address><img class=\"alignnone wp-image-2443 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090346\/Screen-Shot-2014-11-12-at-9.41.55-PM.png\" alt=\"Screen Shot 2014-11-12 at 9.41.55 PM\" width=\"628\" height=\"249\" \/><\/address><address>\u00a0<a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090345\/Screen-Shot-2014-11-12-at-9.42.05-PM.png\"><img class=\"alignnone wp-image-2442 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090345\/Screen-Shot-2014-11-12-at-9.42.05-PM.png\" alt=\"Screen Shot 2014-11-12 at 9.42.05 PM\" width=\"621\" height=\"97\" \/><\/a>\u00a0<\/address><\/div>\r\n<div id=\"m46484-tbl-ch11_04\">Although the masseter and temporalis are responsible for elevating and closing the jaw to break food into digestible pieces, the\u00a0<strong><em>medial pterygoi<\/em><\/strong><a id=\"id711582\"><\/a>\u00a0and\u00a0<strong><em>lateral pterygoid<\/em><\/strong><a id=\"id711596\"><\/a>\u00a0muscles provide assistance in chewing and moving food within the mouth.<\/div>\r\n<\/div>\r\n<div title=\"Muscles That Move the Tongue\">\r\n<div>\r\n<h3 id=\"m46484-fs-id2777277\">Muscles That Move the Tongue<\/h3>\r\n<\/div>\r\nAlthough the tongue is obviously important for tasting food, it is also necessary for mastication,\u00a0<strong><em>deglutition<\/em><\/strong><a id=\"id711626\"><\/a>\u00a0(swallowing), and speech (Figure\u00a011.11\u00a0and\u00a0Figure\u00a011.12). Because it is so moveable, the tongue facilitates complex speech patterns and sounds.\r\n<div id=\"m46484-eip-id2442164\" title=\"Figure\u00a011.11.\u00a0Muscles that Move the Tongue\">\r\n<div>\r\n<div><img src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181722\/1109_Muscles_that_Move_the_Tongue.jpg\" alt=\"Muscles that Move the Tongue (1109_Muscles_that_Move_the_Tongue.jpg)\" width=\"520\" \/><\/div>\r\n<\/div>\r\n<address><strong>Figure\u00a011.11.\u00a0Muscles that Move the Tongue<\/strong><\/address><address>\u00a0<\/address><address>\u00a0<\/address><\/div>\r\n<div id=\"m46484-fig-ch11_03_05\" title=\"Figure\u00a011.12.\u00a0Muscles for Tongue Movement, Swallowing, and Speech\">\r\n<div>\r\n<div><img src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181723\/1127_Muscles_for_Tongue_Movement_Swallowing_and_Speech.jpg\" alt=\"This table describes the muscles used in tongue movement, swallowing, and speech. The genioglossus moves the tongue down and sticks the tongue out of the mouth. It originates in the mandible. The styloglossus moves the tongue up and retracts the tongue back into the mouth. It originates in the temporal bone. The hyoglossus flattens the tongue. It originates in the hyoid bone. The palatoglossus bulges the tongue. It originates in the soft palate. The digastric raises the hyoid bone in a way that also raises the larynx, allowing the epiglottis to cover the glottis during deglutition; it also assists in opening the mouth by depressing the mandible. It originates in the mandible and temporal bone. The stylohyoid raises and retracts the hyoid bone in a way that elongates the oral cavity during deglutition. It originates in the temporal bone. The mylohyoid raises the hyoid bone in a way that presses the tongue against the roof of the mouth, pushing food back into the pharynx during deglutition. It originates in the mandible. The geniohyoid raises and moves the hyoid bone forward, widening the pharynx during deglutition. It originates in the mandible. The ornohyoid retracts the hyoid bone and moves it down during later phases of deglutition. It originates in the scapula. The sternohyoid depresses the hyoid bone during swallowing and speaking. It originates in the clavicle. The thyrohyoid shrinks the distance between thyroid cartilage and the hyoid bone, allowing production of high-pitch vocalizations. It originates in the hyroid cartilage. The sternothyroid depresses the larynx, thyroid cartilage, and hyoid bone to create different vocal tones. It originates in the sternum. The sternocleidomastoid and semispinalis capitis rotate and tilt the head to the side and forward. They originate in the sternum and clavicle. The splenius capitis and longissimus capitis rotate and tilt the head to the side and backwards.\" width=\"520\" \/><\/div>\r\n<\/div>\r\n<address><strong>Figure\u00a011.12.\u00a0Muscles for Tongue Movement, Swallowing, and Speech<\/strong><\/address><address>\u00a0<\/address><\/div>\r\nTongue muscles can be extrinsic or intrinsic. Extrinsic tongue muscles insert into the tongue from outside origins, and the intrinsic tongue muscles insert into the tongue from origins within it. The extrinsic muscles move the whole tongue in different directions, whereas the intrinsic muscles allow the tongue to change its shape (such as, curling the tongue in a loop or flattening it).\r\n\r\nThe extrinsic muscles all include the word root glossus (glossus = \u201ctongue\u201d), and the muscle names are derived from where the muscle originates. The\u00a0<strong><em>genioglossus<\/em><\/strong><a id=\"id711750\"><\/a>\u00a0(genio = \u201cchin\u201d) originates on the mandible and allows the tongue to move downward and forward. The\u00a0<strong><em>styloglossus<\/em><\/strong><a id=\"id711765\"><\/a>\u00a0originates on the styloid bone, and allows upward and backward motion. The\u00a0<strong><em>palatoglossus<\/em><\/strong><a id=\"id711779\"><\/a>\u00a0originates on the soft palate to elevate the back of the tongue, and the\u00a0<strong><em>hyoglossus<\/em><\/strong><a id=\"id711793\"><\/a>\u00a0originates on the hyoid bone to move the tongue downward and flatten it.\r\n<div id=\"m46484-fs-id2369842\">\r\n<div class=\"bcc-box bcc-success\">\r\n<h3>Everyday Connections: Anesthesia and the Tongue Muscles<\/h3>\r\n<div title=\"Muscles That Move the Tongue\">\r\n<div id=\"m46484-fs-id2369842\">\r\n<div>\r\n<p title=\"Anesthesia and the Tongue Muscles\">Before surgery, a patient must be made ready for general anesthesia. The normal homeostatic controls of the body are put \u201con hold\u201d so that the patient can be prepped for surgery. Control of respiration must be switched from the patient\u2019s homeostatic control to the control of the anesthesiologist. The drugs used for anesthesia relax a majority of the body\u2019s muscles.<\/p>\r\nAmong the muscles affected during general anesthesia are those that are necessary for breathing and moving the tongue. Under anesthesia, the tongue can relax and partially or fully block the airway, and the muscles of respiration may not move the diaphragm or chest wall. To avoid possible complications, the safest procedure to use on a patient is called endotracheal intubation. Placing a tube into the trachea allows the doctors to maintain a patient\u2019s (open) airway to the lungs and seal the airway off from the oropharynx. Post-surgery, the anesthesiologist gradually changes the mixture of the gases that keep the patient unconscious, and when the muscles of respiration begin to function, the tube is removed. It still takes about 30 minutes for a patient to wake up, and for breathing muscles to regain control of respiration. After surgery, most people have a sore or scratchy throat for a few days.<span style=\"line-height: 1.5em; background-color: #ffffff;\">\u00a0<\/span>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<strong><span style=\"font-size: 1.17em; line-height: 1.5em;\">Muscles of the Anterior Neck<\/span><\/strong>\r\n\r\n<\/div>\r\n<\/div>\r\n<div title=\"Muscles of the Anterior Neck\">\r\n\r\nThe muscles of the anterior neck assist in deglutition (swallowing) and speech by controlling the positions of the larynx (voice box), and the hyoid bone, a horseshoe-shaped bone that functions as a solid foundation on which the tongue can move. The muscles of the neck are categorized according to their position relative to the hyoid bone (Figure\u00a011.13).\u00a0<strong><em>Suprahyoid muscles<\/em><\/strong><a id=\"id711878\"><\/a>\u00a0are superior to it, and the<strong>\u00a0<em>infrahyoid muscles<\/em><\/strong><a id=\"id711891\"><\/a>\u00a0are located inferiorly.\r\n<div id=\"m46484-fig-ch11_03_06\" title=\"Figure\u00a011.13.\u00a0Muscles of the Anterior Neck\">\r\n<div>\r\n<div><img src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181725\/1110_Muscle_of_the_Anterior_Neck.jpg\" alt=\"This figure shows the front view of a person\u2019s neck with the major muscle groups labeled.\" width=\"420\" \/><\/div>\r\n<\/div>\r\n<address><strong>Figure\u00a011.13.\u00a0Muscles of the Anterior Neck<\/strong><\/address><address>The anterior muscles of the neck facilitate swallowing and speech. The suprahyoid muscles originate from above the hyoid bone in the chin region. The infrahyoid muscles originate below the hyoid bone in the lower neck.<\/address><address>\u00a0<\/address><\/div>\r\nThe suprahyoid muscles raise the hyoid bone, the floor of the mouth, and the larynx during deglutition. These include the\u00a0<strong><em>digastric<\/em><\/strong><a id=\"id711944\"><\/a>\u00a0muscle, which has anterior and posterior bellies that work to elevate the hyoid bone and larynx when one swallows; it also depresses the mandible. The\u00a0<strong><em>stylohyoid<\/em><\/strong><a id=\"id711958\"><\/a>\u00a0muscle moves the hyoid bone posteriorly, elevating the larynx, and the\u00a0<strong><em>mylohyoid<\/em><\/strong><a id=\"id711972\"><\/a>\u00a0muscle lifts it and helps press the tongue to the top of the mouth. The\u00a0<strong><em>geniohyoid<\/em><\/strong><a id=\"id711986\"><\/a>\u00a0depresses the mandible in addition to raising and pulling the hyoid bone anteriorly.\r\n\r\nThe strap-like infrahyoid muscles generally depress the hyoid bone and control the position of the larynx. The\u00a0<strong><em>omohyoid<\/em><\/strong><a id=\"id712008\"><\/a>\u00a0muscle, which has superior and inferior bellies, depresses the hyoid bone in conjunction with the\u00a0<strong><em>sternohyoid<\/em><\/strong><a id=\"id712022\"><\/a>\u00a0and\u00a0<strong><em>thyrohyoid<\/em><\/strong><a id=\"id712036\"><\/a>\u00a0muscles. The thyrohyoid muscle also elevates the larynx\u2019s thyroid cartilage, whereas the\u00a0<strong><em>sternothyroid<\/em><\/strong><a id=\"id712050\"><\/a>\u00a0depresses it to create different tones of voice.\r\n\r\n<\/div>\r\n<div title=\"Muscles That Move the Head\">\r\n<div>\r\n<h3 id=\"m46484-fs-id2468950\">Muscles That Move the Head<\/h3>\r\n<\/div>\r\nThe head, attached to the top of the vertebral column, is balanced, moved, and rotated by the neck muscles (Table\u00a011.5). When these muscles act unilaterally, the head rotates. When they contract bilaterally, the head flexes or extends. The major muscle that laterally flexes and rotates the head is the\u00a0<strong><em>sternocleidomastoid<\/em><\/strong><a id=\"id712090\"><\/a>. In addition, both muscles working together are the flexors of the head. Place your fingers on both sides of the neck and turn your head to the left and to the right. You will feel the movement originate there. This muscle divides the neck into anterior and posterior triangles when viewed from the side (Figure\u00a011.14).\r\n<div id=\"m46484-fig-ch11_03_07\" title=\"Figure\u00a011.14.\u00a0Posterior and Lateral Views of the Neck\">\r\n<div>\r\n<div><img src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181727\/1111_Posterior_and_Side_Views_of_the_Neck.jpg\" alt=\"The left panel shows the lateral view of the neck. The middle panel shows the superficial neck muscles, and the right panel shows the deep neck muscles\" width=\"655\" \/><\/div>\r\n<\/div>\r\n<address><strong>Figure\u00a011.14.\u00a0Posterior and Lateral Views of the Neck<\/strong><\/address><address>The superficial and deep muscles of the neck are responsible for moving the head, cervical vertebrae, and scapulas.<\/address><address>\u00a0<\/address><address>\u00a0<a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090347\/Screen-Shot-2014-11-12-at-9.45.52-PM.png\"><img class=\"alignnone wp-image-2444 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090347\/Screen-Shot-2014-11-12-at-9.45.52-PM.png\" alt=\"Screen Shot 2014-11-12 at 9.45.52 PM\" width=\"650\" height=\"414\" \/><\/a><\/address><\/div>\r\n<h2 id=\"m46484-tbl-ch11_05\">Muscles of the Posterior Neck and the Back<\/h2>\r\n<\/div>\r\n<div title=\"Muscles of the Posterior Neck and the Back\">\r\n\r\nThe posterior muscles of the neck are primarily concerned with head movements, like extension. The back muscles stabilize and move the vertebral column, and are grouped according to the lengths and direction of the fascicles.\r\n\r\nThe\u00a0<strong><em>splenius<\/em><\/strong>\u00a0muscles originate at the midline and run laterally and superiorly to their insertions. From the sides and the back of the neck, the\u00a0<strong><em>splenius capitis<\/em><\/strong>\u00a0inserts onto the head region, and the\u00a0<strong><em>splenius cervicis<\/em><\/strong>\u00a0extends onto the cervical region. These muscles can extend the head, laterally flex it, and rotate it (Figure\u00a011.15).\r\n<div id=\"m46484-fig-ch11_03_08\" title=\"Figure\u00a011.15.\u00a0Muscles of the Neck and Back\">\r\n<div>\r\n<div><img src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181729\/1117_Muscles_of_the_Neck_and_Back.jpg\" alt=\"The top left panel shows a lateral view of the muscles of the neck, and the bottom left panel shows the posterior view of the superficial and deep muscles of the neck. The center panel shows the deep muscles of the back, and the right panel shows the deep spinal muscles.\" width=\"520\" \/><\/div>\r\n<\/div>\r\n<address><strong>Figure\u00a011.15.\u00a0Muscles of the Neck and Back<\/strong><\/address><address>The large, complex muscles of the neck and back move the head, shoulders, and vertebral column.<\/address><address>\u00a0<\/address><\/div>\r\nThe\u00a0<strong><em>erector spinae group<\/em><\/strong>\u00a0forms the majority of the muscle mass of the back and it is the primary extensor of the vertebral column. It controls flexion, lateral flexion, and rotation of the vertebral column, and maintains the lumbar curve. The erector spinae comprises the iliocostalis (laterally placed) group, the longissimus (intermediately placed) group, and the spinalis (medially placed) group.\r\n\r\nThe<strong>\u00a0<em>iliocostalis group<\/em><\/strong>\u00a0includes the\u00a0<strong><em>iliocostalis cervicis<\/em><\/strong>, associated with the cervical region; the\u00a0<strong><em>iliocostalis thoracis<\/em><\/strong>, associated with the thoracic region; and the\u00a0<strong><em>iliocostalis lumborum<\/em><\/strong>, associated with the lumbar region. The three muscles of the<strong>\u00a0<em>longissimus group<\/em><\/strong>\u00a0are the\u00a0<strong><em>longissimus capitis<\/em><\/strong>, associated with the head region; the<strong>\u00a0<em>longissimus cervicis<\/em><\/strong>, associated with the cervical region; and the\u00a0<strong><em>longissimus thoracis<\/em><\/strong>, associated with the thoracic region. The third group, the\u00a0<strong><em>spinalis group<\/em><\/strong>, comprises the\u00a0<strong><em>spinalis capitis<\/em><\/strong>\u00a0(head region), the\u00a0<strong><em>spinalis cervicis<\/em><\/strong>\u00a0(cervical region), and the\u00a0<strong><em>spinalis thoracis<\/em><\/strong>\u00a0(thoracic region).\r\n\r\nThe\u00a0<strong><em>transversospinales<\/em><\/strong>\u00a0muscles run from the transverse processes to the spinous processes of the vertebrae. Similar to the erector spinae muscles, the semispinalis muscles in this group are named for the areas of the body with which they are associated. The semispinalis muscles include the\u00a0<strong><em>semispinalis capitis<\/em><\/strong>, the<strong>\u00a0<em>semispinalis cervicis<\/em><\/strong>, and the\u00a0<strong><em>semispinalis thoracis<\/em><\/strong>. The\u00a0<strong><em>multifidus<\/em><\/strong>\u00a0muscle of the lumbar region helps extend and laterally flex the vertebral column.\r\n\r\nImportant in the stabilization of the vertebral column is the\u00a0<strong><em>segmental muscle group<\/em><\/strong>, which includes the interspinales and intertransversarii muscles. These muscles bring together the spinous and transverse processes of each consecutive vertebra. Finally, the\u00a0<strong><em>scalene muscles<\/em><\/strong>\u00a0work together to flex, laterally flex, and rotate the head. They also contribute to deep inhalation. The scalene muscles include the\u00a0<strong><em>anterior scalene<\/em><\/strong>\u00a0muscle (anterior to the middle scalene), the\u00a0<strong><em>middle scalene<\/em><\/strong>\u00a0muscle (the longest, intermediate between the anterior and posterior scalenes), and the<strong>\u00a0<em>posterior scalene<\/em><\/strong>\u00a0muscle (the smallest, posterior to the middle scalene).\r\n\r\n&nbsp;\r\n\r\n<\/div>\r\n<\/div>\r\n<div title=\"11.4.\u00a0Axial Muscles of the Abdominal Wall and Thorax\" xml:lang=\"en\"><\/div>","rendered":"<div title=\"11.3.\u00a0Axial Muscles of the Head, Neck, and Back\" xml:lang=\"en\">\n<div>\n<div>\n<div class=\"bcc-box bcc-highlight\">\n<h3>Learning Objectives<\/h3>\n<ul>\n<li>Identify the axial muscles of the face, head, and neck<\/li>\n<li>Identify the movement and function of the face, head, and neck muscles<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<\/div>\n<div>\n<ul>\n<li><a href=\"#m46484-fs-id1637749\">Muscles That Create Facial Expression<\/a><\/li>\n<li><a href=\"#m46484-fs-id2921724\">Muscles That Move the Eyes<\/a><\/li>\n<li><a href=\"#m46484-fs-id2518486\">Muscles That Move the Lower Jaw<\/a><\/li>\n<li><a href=\"#m46484-fs-id2777277\">Muscles That Move the Tongue<\/a><\/li>\n<li><a href=\"#m46484-fs-id1962667\">Muscles of the Anterior Neck<\/a><\/li>\n<li><a href=\"#m46484-fs-id2468950\">Muscles That Move the Head<\/a><\/li>\n<li><a href=\"#m46484-fs-id2009136\">Muscles of the Posterior Neck and the Back<\/a><\/li>\n<\/ul>\n<\/div>\n<p>The skeletal muscles are divided into\u00a0<strong><em>axial<\/em><\/strong><a id=\"id710578\"><\/a>\u00a0(muscles of the trunk and head) and\u00a0<strong><em>appendicular<\/em><\/strong><a id=\"id710592\"><\/a>\u00a0(muscles of the arms and legs) categories. This system reflects the bones of the skeleton system, which are also arranged in this manner. The axial muscles are grouped based on location, function, or both. Some of the axial muscles may seem to blur the boundaries because they cross over to the appendicular skeleton. The first grouping of the axial muscles you will review includes the muscles of the head and neck, then you will review the muscles of the vertebral column, and finally you will review the oblique and rectus muscles.<\/p>\n<div title=\"Muscles That Create Facial Expression\">\n<div>\n<h3 id=\"m46484-fs-id1637749\">Muscles That Create Facial Expression<\/h3>\n<\/div>\n<p>The origins of the muscles of facial expression are on the surface of the skull (remember, the origin of a muscle does not move). The insertions of these muscles have fibers intertwined with connective tissue and the dermis of the skin. Because the muscles insert in the skin rather than on bone, when they contract, the skin moves to create facial expression (Figure\u00a011.7).<\/p>\n<div id=\"m46484-fig-ch11_03_01\" title=\"Figure\u00a011.7.\u00a0Muscles of Facial Expression\">\n<div>\n<div><img decoding=\"async\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181708\/1106_Front_and_Side_Views_of_the_Muscles_of_Facial_Expressions.jpg\" alt=\"The left panel in this figure shows the anterior view of the facial muscles, and the right panel shows the lateral view.\" width=\"520\" \/><\/div>\n<\/div>\n<address><strong>Figure\u00a011.7.\u00a0Muscles of Facial Expression<\/strong><\/address>\n<address>Many of the muscles of facial expression insert into the skin surrounding the eyelids, nose and mouth, producing facial expressions by moving the skin rather than bones.<\/address>\n<address>\u00a0<\/address>\n<\/div>\n<p>The\u00a0<strong><em>orbicularis oris<\/em><\/strong><a id=\"id710677\"><\/a>\u00a0is a circular muscle that moves the lips, and the\u00a0<strong><em>orbicularis oculi<\/em><\/strong><a id=\"id710690\"><\/a>\u00a0is a circular muscle that closes the eye. The\u00a0<strong><em>occipitofrontalis<\/em><\/strong><a id=\"id710704\"><\/a>\u00a0muscle moves up the scalp and eyebrows. The muscle has a frontal belly and an occipital (near the occipital bone on the posterior part of the skull) belly. In other words, there is a muscle on the forehead (<em><strong>frontalis<\/strong><\/em><a id=\"id710719\"><\/a>) and one on the back of the head (<em><strong>occipitalis<\/strong><\/em><a id=\"id710732\"><\/a>), but there is no muscle across the top of the head. Instead, the two bellies are connected by a broad tendon called the\u00a0<strong><em>epicranial aponeurosis<\/em><\/strong><a id=\"id710746\"><\/a>, or galea aponeurosis (galea = \u201capple\u201d). The physicians originally studying human anatomy thought the skull looked like an apple.<\/p>\n<p>The majority of the face is composed of the\u00a0<strong><em>buccinator<\/em><\/strong><a id=\"id710769\"><\/a>\u00a0muscle, which compresses the cheek. This muscle allows you to whistle, blow, and suck; and it contributes to the action of chewing. There are several small facial muscles, one of which is the\u00a0<strong><em>corrugator supercilii<\/em><\/strong><a id=\"id710784\"><\/a>, which is the prime mover of the eyebrows. Place your finger on your eyebrows at the point of the bridge of the nose. Raise your eyebrows as if you were surprised and lower your eyebrows as if you were frowning. With these movements, you can feel the action of the corrugator supercilli. Additional muscles of facial expression are presented in\u00a0Figure\u00a011.8.<\/p>\n<div id=\"m46484-fig-ch11_03_02\" title=\"Figure\u00a011.8.\u00a0Muscles in Facial Expression\">\n<div>\n<div><img decoding=\"async\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181710\/1125_Muscles_in_Facial_Expression.jpg\" alt=\"This table describes the muscles used in facial expressions. To furrow the brow, the skin of the scalp moves in an anterior direction. The prime mover is the occipitofrontalis frontal belly, which originates from the epicraneal aponeurosis and inserts underneath the skin of the forehead. To unfurrow the brow, the skin of the scalp moves in the posterior direction. The prime mover is the occipitofrontalis occipital belly, which originates from the occipital bone and the mastoid process of the temporal bone and inserts into the epicraneal aponeurosis. To lower the eyebrows, as when scowling or frowning, the skin underneath the eyebrows moves in an inferior direction. The prime mover is the corrugator supercilii, which originates from the frontal bone and inserts into the skin underneath the eyebrow. To flare the nostrils, the nasal cartilage is compressed in an inferior and posterior direction. The prime mover is the nasalis, which originates from the maxilla and inserts into the nasal bone. Raising the upper lip involves elevating the upper lip tissue. The prime mover is the levator labii superioris, which originates from the maxilla and inserts underneath the skin at the corners of the mouth and also into the orbicularis oris. Lowering the lower lip involves depressing the lip and also moving it laterally. The prime mover is the depressor angulus oris, which originates from the mandible and inserts underneath the skin of the lower lip. Opening the mouth and sliding the lower jaw left and right involves depressing the lower jaw and also moving it laterally. The prime mover is thecdepressor angulus oris, which originates from the mandible and inserts underneath the skin at the corners of the mouth. Smiling involves elevating the corners of the mouth and also moving them in a lateral direction. The prime mover is the zygomaticus major, which originates from the zygomatic bone and inserts underneath the skin at the corners of the mouth in the dimple area, and also into the orbicularis oris. Shaping of the lips as during speech involves moving the lips in multiple directions. The prime mover is the orbicularis oris which originates from the tissue surrounding the lips and inserts underneath the skin at the corners of the mouth. Lateral movement of the cheeks such as when sucking on a straw or to compress air in the mouth while blowing involves moving the cheeks in a lateral direction. The prime mover is the buccinator, which originates from the maxilla, the mandible, and the sphenoid bone via the pterygomandibular raphae, and inserts into the orbicularis oris. Pursing of the lips by straightening them laterally involves moving the corners of the mouth in a lateral direction. The prime mover is the risorius, which originates from the fascia of the parotid salivary gland and inserts underneath the skin at the corners of the mouth. Protrusion of the lower lip, as when making a pouting expression, involves protracting the lower lip and the skin of the chin. The prime mover is the mentalis, which originates from the mandible and inserts underneath the skin of the chin. Raising the upper lip involves elevating the upper lip. The prime mover is the levator labii superioris, which originates from the maxilla and inserts underneath the skin at the corners of the mouth and also into the orbicularis oris.\" width=\"520\" \/><\/div>\n<\/div>\n<address><strong>Figure\u00a011.8.\u00a0Muscles in Facial Expression<\/strong><\/address>\n<address>\u00a0<\/address>\n<\/div>\n<\/div>\n<div title=\"Muscles That Move the Eyes\">\n<div>\n<h3 id=\"m46484-fs-id2921724\">Muscles That Move the Eyes<\/h3>\n<\/div>\n<p>The movement of the eyeball is under the control of the\u00a0<strong><em>extrinsic eye muscles<\/em><\/strong><a id=\"id710909\"><\/a>, which originate outside the eye and insert onto the outer surface of the white of the eye. These muscles are located inside the eye socket and cannot be seen on any part of the visible eyeball (Figure\u00a011.9\u00a0and\u00a0Table\u00a011.3). If you have ever been to a doctor who held up a finger and asked you to follow it up, down, and to both sides, he or she is checking to make sure your eye muscles are acting in a coordinated pattern.<\/p>\n<div id=\"m46484-fig-ch11_03_03\" title=\"Figure\u00a011.9.\u00a0Muscles of the Eyes\">\n<div>\n<div><img decoding=\"async\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181714\/1107_The_Extrinsic_Eye_Muscles.jpg\" alt=\"The left panel shows the lateral view of the muscles for the right eye, and the right panel shows the anterior view of the muscles for the right eye.\" width=\"525\" \/><\/div>\n<\/div>\n<address><strong>Figure\u00a011.9.\u00a0Muscles of the Eyes<\/strong><\/address>\n<address>(a) The extrinsic eye muscles originate outside of the eye on the skull. (b) Each muscle inserts onto the eyeball.<\/address>\n<address>\u00a0<\/address>\n<address><a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090343\/Screen-Shot-2014-11-12-at-9.38.02-PM.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-2440 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090343\/Screen-Shot-2014-11-12-at-9.38.02-PM.png\" alt=\"Screen Shot 2014-11-12 at 9.38.02 PM\" width=\"650\" height=\"559\" \/><\/a>\u00a0<\/address>\n<address>\u00a0 \u00a0\u00a0<a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090342\/Screen-Shot-2014-11-12-at-9.38.18-PM.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-2439 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090342\/Screen-Shot-2014-11-12-at-9.38.18-PM.png\" alt=\"Screen Shot 2014-11-12 at 9.38.18 PM\" width=\"630\" height=\"95\" \/><\/a><\/address>\n<\/div>\n<div><\/div>\n<h3 id=\"m46484-tbl-ch11_03\">Muscles That Move the Lower Jaw<\/h3>\n<\/div>\n<div title=\"Muscles That Move the Lower Jaw\">\n<p>In anatomical terminology, chewing is called\u00a0<strong><em>mastication<\/em><\/strong>. Muscles involved in chewing must be able to exert enough pressure to bite through and then chew food before it is swallowed (Figure\u00a011.10\u00a0and\u00a0Table\u00a011.4). The\u00a0<strong><em>masseter<\/em><\/strong>\u00a0muscle is the main muscle used for chewing because it elevates the mandible (lower jaw) to close the mouth, and it is assisted by the\u00a0<strong><em>temporalis<\/em><\/strong>\u00a0muscle, which retracts the mandible. You can feel the temporalis move by putting your fingers to your temple as you chew.<\/p>\n<div id=\"m46484-fig-ch11_03_04\" title=\"Figure\u00a011.10.\u00a0Muscles That Move the Lower Jaw\">\n<div>\n<div><img decoding=\"async\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181718\/1108_Muscle_that_Move_the_Lower_Jaw.jpg\" alt=\"The left panel of this figure shows the superficial chewing muscles in face, and the right panel shows the deep chewing muscles.\" width=\"485\" \/><\/div>\n<\/div>\n<address><strong>Figure\u00a011.10.\u00a0Muscles That Move the Lower Jaw<\/strong><\/address>\n<address>The muscles that move the lower jaw are typically located within the cheek and originate from processes in the skull. This provides the jaw muscles with the large amount of leverage needed for chewing.<\/address>\n<address><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-2443 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090346\/Screen-Shot-2014-11-12-at-9.41.55-PM.png\" alt=\"Screen Shot 2014-11-12 at 9.41.55 PM\" width=\"628\" height=\"249\" \/><\/address>\n<address>\u00a0<a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090345\/Screen-Shot-2014-11-12-at-9.42.05-PM.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-2442\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090345\/Screen-Shot-2014-11-12-at-9.42.05-PM.png\" alt=\"Screen Shot 2014-11-12 at 9.42.05 PM\" width=\"621\" height=\"97\" \/><\/a>\u00a0<\/address>\n<\/div>\n<div id=\"m46484-tbl-ch11_04\">Although the masseter and temporalis are responsible for elevating and closing the jaw to break food into digestible pieces, the\u00a0<strong><em>medial pterygoi<\/em><\/strong><a id=\"id711582\"><\/a>\u00a0and\u00a0<strong><em>lateral pterygoid<\/em><\/strong><a id=\"id711596\"><\/a>\u00a0muscles provide assistance in chewing and moving food within the mouth.<\/div>\n<\/div>\n<div title=\"Muscles That Move the Tongue\">\n<div>\n<h3 id=\"m46484-fs-id2777277\">Muscles That Move the Tongue<\/h3>\n<\/div>\n<p>Although the tongue is obviously important for tasting food, it is also necessary for mastication,\u00a0<strong><em>deglutition<\/em><\/strong><a id=\"id711626\"><\/a>\u00a0(swallowing), and speech (Figure\u00a011.11\u00a0and\u00a0Figure\u00a011.12). Because it is so moveable, the tongue facilitates complex speech patterns and sounds.<\/p>\n<div id=\"m46484-eip-id2442164\" title=\"Figure\u00a011.11.\u00a0Muscles that Move the Tongue\">\n<div>\n<div><img decoding=\"async\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181722\/1109_Muscles_that_Move_the_Tongue.jpg\" alt=\"Muscles that Move the Tongue (1109_Muscles_that_Move_the_Tongue.jpg)\" width=\"520\" \/><\/div>\n<\/div>\n<address><strong>Figure\u00a011.11.\u00a0Muscles that Move the Tongue<\/strong><\/address>\n<address>\u00a0<\/address>\n<address>\u00a0<\/address>\n<\/div>\n<div id=\"m46484-fig-ch11_03_05\" title=\"Figure\u00a011.12.\u00a0Muscles for Tongue Movement, Swallowing, and Speech\">\n<div>\n<div><img decoding=\"async\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181723\/1127_Muscles_for_Tongue_Movement_Swallowing_and_Speech.jpg\" alt=\"This table describes the muscles used in tongue movement, swallowing, and speech. The genioglossus moves the tongue down and sticks the tongue out of the mouth. It originates in the mandible. The styloglossus moves the tongue up and retracts the tongue back into the mouth. It originates in the temporal bone. The hyoglossus flattens the tongue. It originates in the hyoid bone. The palatoglossus bulges the tongue. It originates in the soft palate. The digastric raises the hyoid bone in a way that also raises the larynx, allowing the epiglottis to cover the glottis during deglutition; it also assists in opening the mouth by depressing the mandible. It originates in the mandible and temporal bone. The stylohyoid raises and retracts the hyoid bone in a way that elongates the oral cavity during deglutition. It originates in the temporal bone. The mylohyoid raises the hyoid bone in a way that presses the tongue against the roof of the mouth, pushing food back into the pharynx during deglutition. It originates in the mandible. The geniohyoid raises and moves the hyoid bone forward, widening the pharynx during deglutition. It originates in the mandible. The ornohyoid retracts the hyoid bone and moves it down during later phases of deglutition. It originates in the scapula. The sternohyoid depresses the hyoid bone during swallowing and speaking. It originates in the clavicle. The thyrohyoid shrinks the distance between thyroid cartilage and the hyoid bone, allowing production of high-pitch vocalizations. It originates in the hyroid cartilage. The sternothyroid depresses the larynx, thyroid cartilage, and hyoid bone to create different vocal tones. It originates in the sternum. The sternocleidomastoid and semispinalis capitis rotate and tilt the head to the side and forward. They originate in the sternum and clavicle. The splenius capitis and longissimus capitis rotate and tilt the head to the side and backwards.\" width=\"520\" \/><\/div>\n<\/div>\n<address><strong>Figure\u00a011.12.\u00a0Muscles for Tongue Movement, Swallowing, and Speech<\/strong><\/address>\n<address>\u00a0<\/address>\n<\/div>\n<p>Tongue muscles can be extrinsic or intrinsic. Extrinsic tongue muscles insert into the tongue from outside origins, and the intrinsic tongue muscles insert into the tongue from origins within it. The extrinsic muscles move the whole tongue in different directions, whereas the intrinsic muscles allow the tongue to change its shape (such as, curling the tongue in a loop or flattening it).<\/p>\n<p>The extrinsic muscles all include the word root glossus (glossus = \u201ctongue\u201d), and the muscle names are derived from where the muscle originates. The\u00a0<strong><em>genioglossus<\/em><\/strong><a id=\"id711750\"><\/a>\u00a0(genio = \u201cchin\u201d) originates on the mandible and allows the tongue to move downward and forward. The\u00a0<strong><em>styloglossus<\/em><\/strong><a id=\"id711765\"><\/a>\u00a0originates on the styloid bone, and allows upward and backward motion. The\u00a0<strong><em>palatoglossus<\/em><\/strong><a id=\"id711779\"><\/a>\u00a0originates on the soft palate to elevate the back of the tongue, and the\u00a0<strong><em>hyoglossus<\/em><\/strong><a id=\"id711793\"><\/a>\u00a0originates on the hyoid bone to move the tongue downward and flatten it.<\/p>\n<div id=\"m46484-fs-id2369842\">\n<div class=\"bcc-box bcc-success\">\n<h3>Everyday Connections: Anesthesia and the Tongue Muscles<\/h3>\n<div title=\"Muscles That Move the Tongue\">\n<div id=\"m46484-fs-id2369842\">\n<div>\n<p title=\"Anesthesia and the Tongue Muscles\">Before surgery, a patient must be made ready for general anesthesia. The normal homeostatic controls of the body are put \u201con hold\u201d so that the patient can be prepped for surgery. Control of respiration must be switched from the patient\u2019s homeostatic control to the control of the anesthesiologist. The drugs used for anesthesia relax a majority of the body\u2019s muscles.<\/p>\n<p>Among the muscles affected during general anesthesia are those that are necessary for breathing and moving the tongue. Under anesthesia, the tongue can relax and partially or fully block the airway, and the muscles of respiration may not move the diaphragm or chest wall. To avoid possible complications, the safest procedure to use on a patient is called endotracheal intubation. Placing a tube into the trachea allows the doctors to maintain a patient\u2019s (open) airway to the lungs and seal the airway off from the oropharynx. Post-surgery, the anesthesiologist gradually changes the mixture of the gases that keep the patient unconscious, and when the muscles of respiration begin to function, the tube is removed. It still takes about 30 minutes for a patient to wake up, and for breathing muscles to regain control of respiration. After surgery, most people have a sore or scratchy throat for a few days.<span style=\"line-height: 1.5em; background-color: #ffffff;\">\u00a0<\/span><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<p><strong><span style=\"font-size: 1.17em; line-height: 1.5em;\">Muscles of the Anterior Neck<\/span><\/strong><\/p>\n<\/div>\n<\/div>\n<div title=\"Muscles of the Anterior Neck\">\n<p>The muscles of the anterior neck assist in deglutition (swallowing) and speech by controlling the positions of the larynx (voice box), and the hyoid bone, a horseshoe-shaped bone that functions as a solid foundation on which the tongue can move. The muscles of the neck are categorized according to their position relative to the hyoid bone (Figure\u00a011.13).\u00a0<strong><em>Suprahyoid muscles<\/em><\/strong><a id=\"id711878\"><\/a>\u00a0are superior to it, and the<strong>\u00a0<em>infrahyoid muscles<\/em><\/strong><a id=\"id711891\"><\/a>\u00a0are located inferiorly.<\/p>\n<div id=\"m46484-fig-ch11_03_06\" title=\"Figure\u00a011.13.\u00a0Muscles of the Anterior Neck\">\n<div>\n<div><img decoding=\"async\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181725\/1110_Muscle_of_the_Anterior_Neck.jpg\" alt=\"This figure shows the front view of a person\u2019s neck with the major muscle groups labeled.\" width=\"420\" \/><\/div>\n<\/div>\n<address><strong>Figure\u00a011.13.\u00a0Muscles of the Anterior Neck<\/strong><\/address>\n<address>The anterior muscles of the neck facilitate swallowing and speech. The suprahyoid muscles originate from above the hyoid bone in the chin region. The infrahyoid muscles originate below the hyoid bone in the lower neck.<\/address>\n<address>\u00a0<\/address>\n<\/div>\n<p>The suprahyoid muscles raise the hyoid bone, the floor of the mouth, and the larynx during deglutition. These include the\u00a0<strong><em>digastric<\/em><\/strong><a id=\"id711944\"><\/a>\u00a0muscle, which has anterior and posterior bellies that work to elevate the hyoid bone and larynx when one swallows; it also depresses the mandible. The\u00a0<strong><em>stylohyoid<\/em><\/strong><a id=\"id711958\"><\/a>\u00a0muscle moves the hyoid bone posteriorly, elevating the larynx, and the\u00a0<strong><em>mylohyoid<\/em><\/strong><a id=\"id711972\"><\/a>\u00a0muscle lifts it and helps press the tongue to the top of the mouth. The\u00a0<strong><em>geniohyoid<\/em><\/strong><a id=\"id711986\"><\/a>\u00a0depresses the mandible in addition to raising and pulling the hyoid bone anteriorly.<\/p>\n<p>The strap-like infrahyoid muscles generally depress the hyoid bone and control the position of the larynx. The\u00a0<strong><em>omohyoid<\/em><\/strong><a id=\"id712008\"><\/a>\u00a0muscle, which has superior and inferior bellies, depresses the hyoid bone in conjunction with the\u00a0<strong><em>sternohyoid<\/em><\/strong><a id=\"id712022\"><\/a>\u00a0and\u00a0<strong><em>thyrohyoid<\/em><\/strong><a id=\"id712036\"><\/a>\u00a0muscles. The thyrohyoid muscle also elevates the larynx\u2019s thyroid cartilage, whereas the\u00a0<strong><em>sternothyroid<\/em><\/strong><a id=\"id712050\"><\/a>\u00a0depresses it to create different tones of voice.<\/p>\n<\/div>\n<div title=\"Muscles That Move the Head\">\n<div>\n<h3 id=\"m46484-fs-id2468950\">Muscles That Move the Head<\/h3>\n<\/div>\n<p>The head, attached to the top of the vertebral column, is balanced, moved, and rotated by the neck muscles (Table\u00a011.5). When these muscles act unilaterally, the head rotates. When they contract bilaterally, the head flexes or extends. The major muscle that laterally flexes and rotates the head is the\u00a0<strong><em>sternocleidomastoid<\/em><\/strong><a id=\"id712090\"><\/a>. In addition, both muscles working together are the flexors of the head. Place your fingers on both sides of the neck and turn your head to the left and to the right. You will feel the movement originate there. This muscle divides the neck into anterior and posterior triangles when viewed from the side (Figure\u00a011.14).<\/p>\n<div id=\"m46484-fig-ch11_03_07\" title=\"Figure\u00a011.14.\u00a0Posterior and Lateral Views of the Neck\">\n<div>\n<div><img decoding=\"async\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181727\/1111_Posterior_and_Side_Views_of_the_Neck.jpg\" alt=\"The left panel shows the lateral view of the neck. The middle panel shows the superficial neck muscles, and the right panel shows the deep neck muscles\" width=\"655\" \/><\/div>\n<\/div>\n<address><strong>Figure\u00a011.14.\u00a0Posterior and Lateral Views of the Neck<\/strong><\/address>\n<address>The superficial and deep muscles of the neck are responsible for moving the head, cervical vertebrae, and scapulas.<\/address>\n<address>\u00a0<\/address>\n<address>\u00a0<a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090347\/Screen-Shot-2014-11-12-at-9.45.52-PM.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-2444 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/198\/2014\/11\/20090347\/Screen-Shot-2014-11-12-at-9.45.52-PM.png\" alt=\"Screen Shot 2014-11-12 at 9.45.52 PM\" width=\"650\" height=\"414\" \/><\/a><\/address>\n<\/div>\n<h2 id=\"m46484-tbl-ch11_05\">Muscles of the Posterior Neck and the Back<\/h2>\n<\/div>\n<div title=\"Muscles of the Posterior Neck and the Back\">\n<p>The posterior muscles of the neck are primarily concerned with head movements, like extension. The back muscles stabilize and move the vertebral column, and are grouped according to the lengths and direction of the fascicles.<\/p>\n<p>The\u00a0<strong><em>splenius<\/em><\/strong>\u00a0muscles originate at the midline and run laterally and superiorly to their insertions. From the sides and the back of the neck, the\u00a0<strong><em>splenius capitis<\/em><\/strong>\u00a0inserts onto the head region, and the\u00a0<strong><em>splenius cervicis<\/em><\/strong>\u00a0extends onto the cervical region. These muscles can extend the head, laterally flex it, and rotate it (Figure\u00a011.15).<\/p>\n<div id=\"m46484-fig-ch11_03_08\" title=\"Figure\u00a011.15.\u00a0Muscles of the Neck and Back\">\n<div>\n<div><img decoding=\"async\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/18\/2014\/07\/19181729\/1117_Muscles_of_the_Neck_and_Back.jpg\" alt=\"The top left panel shows a lateral view of the muscles of the neck, and the bottom left panel shows the posterior view of the superficial and deep muscles of the neck. The center panel shows the deep muscles of the back, and the right panel shows the deep spinal muscles.\" width=\"520\" \/><\/div>\n<\/div>\n<address><strong>Figure\u00a011.15.\u00a0Muscles of the Neck and Back<\/strong><\/address>\n<address>The large, complex muscles of the neck and back move the head, shoulders, and vertebral column.<\/address>\n<address>\u00a0<\/address>\n<\/div>\n<p>The\u00a0<strong><em>erector spinae group<\/em><\/strong>\u00a0forms the majority of the muscle mass of the back and it is the primary extensor of the vertebral column. It controls flexion, lateral flexion, and rotation of the vertebral column, and maintains the lumbar curve. The erector spinae comprises the iliocostalis (laterally placed) group, the longissimus (intermediately placed) group, and the spinalis (medially placed) group.<\/p>\n<p>The<strong>\u00a0<em>iliocostalis group<\/em><\/strong>\u00a0includes the\u00a0<strong><em>iliocostalis cervicis<\/em><\/strong>, associated with the cervical region; the\u00a0<strong><em>iliocostalis thoracis<\/em><\/strong>, associated with the thoracic region; and the\u00a0<strong><em>iliocostalis lumborum<\/em><\/strong>, associated with the lumbar region. The three muscles of the<strong>\u00a0<em>longissimus group<\/em><\/strong>\u00a0are the\u00a0<strong><em>longissimus capitis<\/em><\/strong>, associated with the head region; the<strong>\u00a0<em>longissimus cervicis<\/em><\/strong>, associated with the cervical region; and the\u00a0<strong><em>longissimus thoracis<\/em><\/strong>, associated with the thoracic region. The third group, the\u00a0<strong><em>spinalis group<\/em><\/strong>, comprises the\u00a0<strong><em>spinalis capitis<\/em><\/strong>\u00a0(head region), the\u00a0<strong><em>spinalis cervicis<\/em><\/strong>\u00a0(cervical region), and the\u00a0<strong><em>spinalis thoracis<\/em><\/strong>\u00a0(thoracic region).<\/p>\n<p>The\u00a0<strong><em>transversospinales<\/em><\/strong>\u00a0muscles run from the transverse processes to the spinous processes of the vertebrae. Similar to the erector spinae muscles, the semispinalis muscles in this group are named for the areas of the body with which they are associated. The semispinalis muscles include the\u00a0<strong><em>semispinalis capitis<\/em><\/strong>, the<strong>\u00a0<em>semispinalis cervicis<\/em><\/strong>, and the\u00a0<strong><em>semispinalis thoracis<\/em><\/strong>. The\u00a0<strong><em>multifidus<\/em><\/strong>\u00a0muscle of the lumbar region helps extend and laterally flex the vertebral column.<\/p>\n<p>Important in the stabilization of the vertebral column is the\u00a0<strong><em>segmental muscle group<\/em><\/strong>, which includes the interspinales and intertransversarii muscles. These muscles bring together the spinous and transverse processes of each consecutive vertebra. Finally, the\u00a0<strong><em>scalene muscles<\/em><\/strong>\u00a0work together to flex, laterally flex, and rotate the head. They also contribute to deep inhalation. The scalene muscles include the\u00a0<strong><em>anterior scalene<\/em><\/strong>\u00a0muscle (anterior to the middle scalene), the\u00a0<strong><em>middle scalene<\/em><\/strong>\u00a0muscle (the longest, intermediate between the anterior and posterior scalenes), and the<strong>\u00a0<em>posterior scalene<\/em><\/strong>\u00a0muscle (the smallest, posterior to the middle scalene).<\/p>\n<p>&nbsp;<\/p>\n<\/div>\n<\/div>\n<div title=\"11.4.\u00a0Axial Muscles of the Abdominal Wall and Thorax\" xml:lang=\"en\"><\/div>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-2086\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>Chapter 11. <strong>Authored by<\/strong>: OpenStax College. <strong>Provided by<\/strong>: Rice University. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"http:\/\/cnx.org\/contents\/14fb4ad7-39a1-4eee-ab6e-3ef2482e3e22@7.1@7.1.\">http:\/\/cnx.org\/contents\/14fb4ad7-39a1-4eee-ab6e-3ef2482e3e22@7.1@7.1.<\/a>. <strong>Project<\/strong>: Anatomy &amp; Physiology. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em>. <strong>License Terms<\/strong>: Download for free at http:\/\/cnx.org\/content\/col11496\/latest\/. <\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section>","protected":false},"author":74,"menu_order":4,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"Chapter 11\",\"author\":\"OpenStax College\",\"organization\":\"Rice University\",\"url\":\"http:\/\/cnx.org\/contents\/14fb4ad7-39a1-4eee-ab6e-3ef2482e3e22@7.1@7.1.\",\"project\":\"Anatomy & Physiology\",\"license\":\"cc-by\",\"license_terms\":\"Download for free at http:\/\/cnx.org\/content\/col11496\/latest\/. \"}]","CANDELA_OUTCOMES_GUID":"","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-2086","chapter","type-chapter","status-publish","hentry"],"part":2013,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-ap1\/wp-json\/pressbooks\/v2\/chapters\/2086","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-ap1\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-ap1\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-ap1\/wp-json\/wp\/v2\/users\/74"}],"version-history":[{"count":6,"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-ap1\/wp-json\/pressbooks\/v2\/chapters\/2086\/revisions"}],"predecessor-version":[{"id":3092,"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-ap1\/wp-json\/pressbooks\/v2\/chapters\/2086\/revisions\/3092"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-ap1\/wp-json\/pressbooks\/v2\/parts\/2013"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-ap1\/wp-json\/pressbooks\/v2\/chapters\/2086\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-ap1\/wp-json\/wp\/v2\/media?parent=2086"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-ap1\/wp-json\/pressbooks\/v2\/chapter-type?post=2086"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-ap1\/wp-json\/wp\/v2\/contributor?post=2086"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-ap1\/wp-json\/wp\/v2\/license?post=2086"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}