Caitlin Craig McCoy 11 part one

What is the location and function of the intrinsic tongue muscles? Intrinsic muscles of the tongue are found within the blade (dorsum) of the tongue, the portion that lies in the oral cavity and moves to form the vowels and consonants of speech.

What is the location and function of the extrinsic tongue muscles? Extrinsic muscles of the tongue lie below, behind, and above the blade, enabling it to be extended, retracted, elevated, depressed, and curled. 

Why does movement of the tongue impact other structures of vocal tract? Movements of the tongue have the ability to impact activity in the jaw, larynx, and vocal tract. 

Name and describe the 4 tongue muscles that make up the “muscle sandwich”. Superior and inferior longitudinal tongue muscles are the top and bottom layers of the muscles sandwich. They have long fibers that run from the anterior to the posterior of the dorsum. When they are contracted, simultaneously, the entire dorsum is shortened. Contraction solely in the superior curls the tip of the dorsum upward; contraction solely in the inferior curls the tip of the dorsum downward.

The Horizontal and vertical tongue muscles are the filling of the muscle sandwich. As their names suggest, the horizontal muscles run through the medial/lateral plan of the dorsum, while vertical muscles are oriented from the top to bottom. Contraction in the former narrows the blade and is also responsible for curling the sides upward to form a long furrow; contracting the latter flattens the tongue.

Name and describe the extrinsic tongue muscles. 1) palatoglossus--originates at the soft palate and runs within the walls of the pharynx to insert into the underside of the tongue. It is a dual-purpose muscles that can raise the posterior of the tongue and/or lower the soft palate.

2) styloglossus-- begins at the styloid process, a protrusion of bone immediately in front of and slightly below the ear canal, and inserts into the posterior of the tongue. Contraction retracts and elevates the back of the tongue and assists with curling the central portion. 

3) genioglossus-- the tongue is pulled forward by the genioglossus, a relatively large muscles that fills the interior arch of the mandible and inserts into the underside of the dorsum.

4) hyoglossus--tongue depression is accomplished through the contraction of the hyoglossus, which links the tongue with the hyoid bone. 

What is the biological function of the pharynx and palate? Biologically, the pharynx and palate fulfill two indispensable, life-sustaining functions: they form an airway, allowing the transport of oxygen to the lungs, and they serve as the entrance to the alimentary canal, passing sustenance to the digestive system.

Describe the alveolar ridge. The bony prominence that leads to your hard palate. This ridge plays an important role in the production of consonants, including the plosives /d/ and /t/, the nasal continuent /n/, and the sibilants /s/ and /z/. 

What are the faucial pillars? The faucial pillars (fauces) are seen near the back of the tongue, resembling the vertical sections of a proscenium arch.

What is another name for your soft palate? Velum.

What is the purpose of your uvula? It serves as an important collection point for excess muscus produced in the nasopharynx and nose, which is then dropped directly into the digestive tract. 

Describe the muscles of the pharynx. The superior constrictor muscle, the middle constrictor muscle, and the inferior constrictor muscle wrap around the posterior of the pharynx, connecting to the thyroid cartilage, hyoid bone, stylohyoid ligament, mandible, and skull. While they are intended by nature to assist with swallowing, narrowing the pharynx to help direct food into the esophagus, they are also important in the concept of the "open throat" for singing and speaking; through release of tension in the constrictors.

Palatoglossus--connects to the soft palate and to the tongue via the pharynx. It raises the tongue, narrows the pharynx, and lowers the palate. 

Palatopharyngeus-- originates at the soft palate and courses downward through the pharynx to insert into the thyroid cartilage. There are three possible functions: lowering the palate, tensing and narrowing the pharynx, and elevating the larynx. 

Stylopharyngeal--  originates from the styloid process and runs downward between the superior and middle constrictors, where it merges with the palatopharyngeus and connects to the thyroid cartilage. It elevates the larynx as well. It is the only muscles capable of actively opening the pharynx; however, this action always is accompanied by laryngeal elevation, rendering it of little pedagogical use in creating the open throat desired for optimal voice production. 

salpingopharyngeus-- which forms a narrow band running form the auditory tube downward to merge with the palatopharyngeus. Contraction elevates the lateral walls to narrow the pharynx and also opens the end of the auditory tube to equalize pressure in the middle of the ear.

Describe the muscles of the soft palate. The levator palati muscle is responsible for palatal elevation. it is also known as the levator veli palatine. This muscle forms the bulk of the palate, originates from the temporal bone (skull) and the auditory tube to form a sling-like structure drawing the palate upward and backward at an oblique angle to close against the pharynx. The movement is not large, better measured in millimeters than centimeters. Singers wishing to increase resonance space through palatal elevation also might consider contracting the musculus uvulae, which retracts the uvula upward into the soft palate. The palate is tensed and flattened through contraction of the tensor palati muscle, which--like the levator muscle--connects the palate to the skull and auditory tubes. When contracted, this muscle works together with the palatopharyngeus to open the auditory tubes and equalize air pressure in the middle of the ear.

How do we lower the soft palate? Lowering of the palate can be achieved either passively or actively. If the levator and tensor palati muscles are relaxed, the weight of gravity pressing upon the palate will passively depress it, opening the nasal port. In the prone or supine position, gravity may actually pull the palate against the pharyngeal wall, which can lead to snoring. Both the palatoglossus and palatopharyngeus muscles contract to actively lower the palate.

Describe the jaw.  What is its anatomical name? The jaw or mandible is a single upaired bone that resembles the letter U or V when viewed from above. An upward projection called the ramus is seen at the posterior of each side. Two processes are located at the top of each ramus, the anterior of which is the coronid. When the jaw is elevated and the mouth closed, the coronoid process slips into the opening between the maxillae--colloquially, albeit incorrectly, known as the upper jaw--and the zygomatic bone of the skull (cheekbone). The condylar process, also called the condyle, arises from the posterior of the ramus and articulates with the temporal bone of the skull at the temporomadibular joint (TMJ). This joint can both rotate and translate (slide); these actions can occur simulataneously, thereby increasing the possible range of jaw motion. A band of protective cartilage called the meniscus lies between the condyle and the skull. 

How does the strength of the muscles that close the jaw compare with the muscles of those that open the jaw? Muscles that raise the jaw are robust and very strong-in humans, they can exert sufficient force to break teeth. In contrast, muscles that open the jaw are relatively weak. This imbalance often creates pedagogic challenges to voice student who attempt to control jaw movement through muscular antagonism. 

Describe the primary muscles responsible for jaw elevation (closing)? Masseter-- is a powerful muscle that originates in the zygomatic region (cheekbones) and inserts over most of the ramus. 

internal pterygoid-- originates at the pterygoid plate (the region of the skull between the zygomatic arch and top teeth) and inserts to the inside of the jaw at the base of the ramus. Together, the pterygoid and masseter form a sling-like structure that closes and retracts the jaw, inducing a grinding motion required for masitcation.

temporalis--is a large, fan-shaped muscle that covers most of the side of the head above the ear, inserting into the anterior of the ramus near the coronoid process. Contraction results in a biting or snapping motion of the jaw. 

What is the advantage besides size that the jaw closing muscles have over the jaw opening muscles? The jaw closing muscles gain mechanical advantage through their connections to the skull which is fixed in position relative to the jaw. By contrast most of the muscles that lower the jaw are attached to the moveable hyoid bone. 

How does opening the mouth for everyday life differ from opening the mouth for singing? In everyday life, the jaw generally is dropped by relaxing the closing muscles, assisted by the downward pull of gravity. However, in singing, speaking, and eating, the jaw often must be dropped farther and more quickly than is possible by gravity alone. This is the function of the digastric, mylohyoid, and geniohyoid muscles.

Describe the muscles that can be used to actively open the jaw. The digastric muscle has two bellies. The posterior belly runs from the mastoid process to the hyoid bone and contracts to elevate the larynx when swallowing. The anterior belly continues from the hyoid bone, inserting into the mandible near the point of the chin and contracts to depress the jaw. 
The mylohyoid is the thinnest and least significant of the jaw openers, a fan-shaped muscle originating along the inside of the mandible and inserting into the hyoid bone. The more important function of the mylohyoid is as the muscular floor of the mouth.
The geniohyoid is another relatively thin band of muscle connecting the mandible and hyoid, coursing between the mylohyoid and genioglossus.

Why is muscular antagonism such a bad problem in jaw movement for singing? If resistive tension is present in the jaw closers, the openers--which are dual-function muscles--will induce their secondary action: laryngeal elevation. This action can be somewhat overcome by strong anchoring of the larynx by the sternothyroid, sternohyoid, and omohyoid mucles; however, the resulting tug-of-war will impair vocal freedom and supple tone production.

What is the solution to this problem? The solution is to minimize tension in all jaw muscles during phonation. 

Describe the final two jaw-depressing muscles that do not have a connection to the hyoid. Platysma is a wide thin muscle of the face that is primarily responsible for producing a grimace. While this may help drop the jaw, it also distorts the appearance of the face--a tradeoff few professional voice users are eager to accept. Of greater significance is the lateral pterygoid muscle, which is also known as the pterygoid plate, this muscle travels laterally to insert into the top of the ramus. When contracted, the jaw is pulled forward,slightly rotating the condyle within the temporomandibular joint, and inducing a small dropping of the jaw and opening of the mouth.

What is subluxation of the jaw? Dropping the jaw to maximal opening and creating a space between the ramus and skull. Or dropping the jaw out of its mormal socket in the TM join, is called subluxation.