Systemic anatomy Essay Example for Free

Systemic anatomy Essay The muscles of tongue can be divided into intrinsic and extrinsic groups. The intrinsic muscles lie entirely within the tongue, while the extrinsic muscles attach the tongue to other structures. The extrinsic muscles reposition the tongue, while the intrinsic muscles alter the shape of the tongue for talking and swallowing. Extrinsic tongue muscles, by definition, originate from structures outside the tongue and insert into the tongue. The four paired extrinsic muscles protrude, retract, depress, and elevate the tongue: Muscle From Nerve Function Genioglossus muscle mandible-(Genial Tubercles) hypoglossal nerve Protrudes the tongue as well as depressing its center. Hyoglossus muscle hyoid bone Depresses the tongue. Styloglossus muscle styloid process Elevates and retracts the tongue. Palatoglossus muscle palatine aponeurosis pharyngeal branch of vagus nerve Depresses the soft palate, moves the palatoglossal fold towards the midline, and elevates the back of the tongue. Intrinsic muscles Four paired intrinsic muscles of the tongue originate and insert within the tongue, running along its length. These muscles alter the shape of the tongue by: engthening and shortening it, curling and uncurling its apex and edges, and flattening and rounding its surface. The superior longitudinal muscle runs along the superior surface of the tongue under the mucous membrane, and elevates, assists in retraction of, or deviates the tip of the tongue. It originates near the epiglottis, the hyoid bone, from the median fibrous septum. The inferior longitudinal muscle lines the sides of the tongue, and is Joined to the styloglossus muscle. The verticalis muscle is located in the middle of the tongue, and Joins the superior and inferior longitudinal muscles. The transversus muscle divides the tongue at the ed to the mucous membranes . the tongue that run along the sides 2. The muscle that . -Protrude -Retract -Depress -Retraction, elevation of posterior third -Shape changes The Genioglossus mus protrudes the tongue. Remember that contraction of the right genioglossus muscle (for example) points the tip of the tongue to the patients left. The Styloglossus muscle retracts the tongue upward and backward. Also the Palatoglossus muscle retracts the tongue upward and backward. The Hyoglossus muscle depresses the tongue. The Levator veli palatini muscle elevates the soft palate during swallowing. The Longitudinal, tranverse and vertical muscles of the tongue. They help to change the shape of the tongue. 3. Muscle of pharyngeal wall. The pharyngeal wall is formed by skeletal muscles and by fascia. Gaps between the muscles are reinforced by the fascia and provide routes for structures to pass through the wall. The muscles of the pharynx are organized into two groups based on the orientation of muscle fibers. The constrictor muscles have fibers oriented in a circular direction relative to the pharyngeal wall, whereas the longitudinal muscles have fibers oriented vertically. The three constrictor muscles on each side are major contributors to the structure of the pharyngeal wall and their names indicate their position†superior, middle, and inferior constrictor muscles. Posteriorly, the muscles from each side are Joined together by the pharyngeal raphe. Anteriorly, these muscles attach to bones and ligaments related to the lateral margins of the nasal and oral cavities and the larynx. The constrictor muscles overlap each other in a fashion resembling the walls of three flower pots stacked one on the other. The inferior constrictors overlap the lower margins of the middle constrictors and, in the ame way, the middle constrictors overlap the superior constrictors. Collectively, the muscles constrict or narrow the pharyngeal cavity. When the constrictor muscles contract sequentially from top to bottom, as in swallowing, they move a bolus of food through the pharynx and into the esophagus. All of the constrictors are innervated by the pharyngeal branch of the vagus nerve [X]. The superior constrictor muscles together bracket the upper part of the pharyngeal cavity. Each muscle is attached anteriorly to the pterygoid hamulus, pterygomandibular raphe, and adjacent bone of he mandible. From these attachments , the muscle tans out posteriorly and Joins witn its partner muscle from the other side at the pharyngeal raphe. A special band of muscle (the palatopharyngeal sphincter) originates from the anterolateral surface of the soft palate and circles the inner aspect of the pharyngeal wall, blending with the inner aspect of the superior constrictor. When the superior constrictor constricts during swallowing, it forms a prominent ridge on the deep aspect of the pharyngeal wall that catches the margin of the elevated soft palate, which then seals closed the haryngeal isthmus between the nasopharynx and oropharynx. The middle constrictor muscles are attached to the lower aspect of the stylohyoid ligament, the lesser horn of the hyoid bone, and the entire upper surface of the greater horn of the hyoid. Like the superior constrictors, the middle constrictor muscles fan out posteriorly and attach to the pharyngeal raphe. The posterior part of the middle constrictors overlaps the superior constrictors. The inferior constrictor muscles attach anteriorly to the oblique line of the thyroid cartilage, the cricoid cartilage, and ligament that spans between these two attachments to cartilage and crosses the cricothyroid muscle . Like the other constrictor muscles, the inferior constrictor muscles spread out posteriorly and attach to the pharyngeal raphe. The posterior part of the inferior constrictors overlaps the middle constrictors. Inferiorly, the muscle fibers blend with and attach into the wall of the esophagus. The parts of the inferior constrictors attached to the cricoid cartilage bracket the narrowest part of the pharyngeal cavity. Longitudinal muscles The three longitudinal muscles of the pharyngeal wall are named according to their rigins†stylopharyngeus from the styloid process of the temporal bone, salpingopharyngeus from the cartilaginous part of the pharyngotympanic tube (salpinx is Greek for tube), and palatopharyngeus from the soft palate. From their sites of origin, these muscles descend and attach into the pharyngeal wall. Longitudinal muscles of the pharynx The longitudinal muscles elevate the pharyngeal wall, or during swallowing, pull the pharyngeal wall up and over a bolus of food being moved through the pharynx and into the esophagus. Stylopharyngeus The cylindrical stylopharyngeus muscle originates from the base of the medial urface of the styloid process of the temporal bone, descends between the superior and middle constrictor muscles to fan out on, and blend with, the deep surface of the pharyngeal wall. It is innervated by the glossopharyngeal nerve [1;0. Salpingopharyngeus Salpingopharyngeus is a small muscle originating from the inferior aspect of the pharyngotympanic tube, descending on, and blending into the deep surface of the pharyngeal wall. It is innervated by the vagus nerve [X]. Palatopharyngeus Palatopharyngeus , in addition to being a muscle of the pharynx, is also a muscle of the soft palate . It is attached to the upper surface of the palatine aponeurosis, and passes posteriorly and inferiorly to blend with the deep surface of the pharyngeal wall. Palatopharyngeus forms an important fold in the overlying mucosa (the palatopharyngeal arch). This arch is visible through the oral cavity and is a landmark for finding the palatine tonsil, which is immediately anterior to it on the oropharyngeal wall. The larynx, or voicebox, is an organ in the neck that plays a crucial role in speech and breathing. The larynx is the point at which t aerodigestive tract splits into two separate pathways: the inspired air travels through he trachea, or windpipe, into the lungs, and swallowed food enters the esophagus and passes into the stomach. Because of its location, the larynx has three important functions control of the airflow during breathing protection of the airway production of sound for speech. The larynx consisted of a framework of cartilage with surrounding soft tissue. The most prominent piece of cartilage is a shield-shaped structure called the thyroid cartilage. The anterior portion of the thyroid cartilage can be easily felt in thin necks as the Adams apple. Superior to the larynx (sometimes considered part of the arynx itself) is a U-shaped bone called the hyoid. The hyoid bone supports the larynx from above and is itself attached to the mandible by muscles and tendons. These attachments are important in elevating the larynx during swallowing and speech. The lower part of the larynx consists of a circular piece of cartilage called the cricoid cartilage. This cartilage is shaped like a signet ring with the larger portion of the ring in the back. Below the cricoid are the rings of the trachea. In the center of the larynx lie the vocal folds (also known as the vocal cords). The vocal folds are one of the most mportant parts of the larynx, as they play a key role in all three functions mentioned above. The vocal folds are made of muscles covered by a thin layer called mucosa. There is a right and left fold, forming a V when viewed from above. At the rear portion of each vocal fold is a small structure made of cartilage called the arytenoid. Many small muscles, described below, are attached to the arytenoids. These muscles pull the arytenoids apart from each other during breathing, thereby opening the airway. During speech the arytenoids and therefore the vocal folds are brought close together. As the air passes by the vocal folds in this position, they open and close very quickly. The rapid pulsation of air passing through the vocal folds produces a sound that is then modified by the remainder of the vocal tract to produce speech. This process is described in more detail in the page on vocal fold vibration. 4. Give the cartilage of larynx. Describe each. Laryngeal cartilages can refer to: The arytenoid cartilages are a pair of small three-sided pyramids which form part of the larynx, to which the vocal folds (vocal cords) are attached. These allow and aid in the vocal cords movement. Each is pyramidal or ladle-shaped in form and has three surfaces, a base, and an apex. The cricoid cartilage or simply cricoid is the only complete ring of cartilage around the trachea. The epiglottis is a flap that is made of elastic cartilage tissue covered with a mucous membrane, attached to the entrance of the larynx. It projects obliquely upwards behind the tongue and the hyoid bone, pointing dorsally. There are taste buds on the epiglottis. The thyroid cartilage is the largest of the nine cartilages that make up the laryngeal skeleton, the cartilage structure in and around the tracheathat contains the larynx. It is composed of two plate-like laminae that fuse on the anterior side of the cartilage to form a peak, called the laryngeal prominence. This prominence is often referred to as the pomus Adam' or Adams apple. The laryngeal prominence is more prominent in adult male than temale because ot 1200 in female. 5. Muscle of soft palate. Muscle Action levator veli palatini deglutition ne difference in the size ot the angle: 900 in male and Vagus nerve via pharyngeal plexus tensor veli palatini mandibular nerve palatoglossus respiration palatopharyngeus musculus uvulae moves uvula