Oral Transit Stage

Swallowing is the movement of food from the mouth into the Esophagus. The esophagus secretes mucus and transports the food to the stomach via peristalsis.

Digestion starts in mouth and it is going through several steps. Teeth which are a Mechanical digestion start tearing and crushing the food down into small pieces so that the food will smoothly run down our throat. The salivary glands are located underneath the back of our tongues and that’s what is creating our saliva. The saliva is the Chemical Digestion is helping soften the food in the mouth so it is easy to swallow. Also saliva is the first out of several chemicals that is breaking the food into smaller bits. The tongue is the muscle that works with the food and saliva to form something similar to balls that can be swallowed. Also tongue contains taste buds so that we know if the food is salt, sweet, sour or bitter. Esophangus is a simple transportation tube that is joining the throat with stomach. When swallowing we are closing a trap door in our throats called the epiglottis. By closing this trap we are preventing the food prom going to trachea and into our lungs. Also Food moves down the esophangus using muscles not gravity. Stomach is the first stop after the Esophangus. When the food gets into stomach the stomach uses chemicals to try to make the food smaller. These chemicals are called gastric juices and they include hydrochloric acid and enzymes. (Enzymes are

3) Once a bolus of food has been formed in the mouth, it is passed by the tongue and jaws to the

➢ After leaving the pharynx, air enters the ;larynx, where two pairs of ligaments, together with the mucosa covering them, forms the vestibular and vocal folds. These folds help prevent foreign particles, including food, from entering the lower respiratory system.

* The nervous phase = this is where the presence of the food within the mouth and the action of swallowing resulted in the reflex stimulation of the mucus cells so that the gastric juice can be released.

Involuntary pharyngeal: stage begins as the bolus passes into the oropharynx - receptors send impulses to the deglutition center in the medulla and pons. Returning impulses cause the soft palate to move superiorly and posteriorly to close the nasopharynx. The epiglottis moves slightly inferiorly to close the glottis.

The process of digestion first begins in the mouth by in taking food (bolus). The teeth help with masticating (chewing and breaking food particles down) allowing for swallowing and increasing surface area for chemical digestion. Enzymes found in saliva also facilitates with the chemical break down of food primarily starches and fats. The food swallowed then enters into the esophagus (a tube connecting the mouth and stomach). Peristalsis helps the esophagus to push the food in the direction of the stomach. The stomach contents are highly acidic (doesn’t affect the stomach mucosa since cells secrete mucus allowing the stomach wall to be protected) with pH levels between 1.5-2.5 allowing microorganisms to be killed, breaking down of food, and activating digestive enzymes producing a thick substance known as chyme. However, breaking down of foods further occurs in the small intestine consisting of: bile created from the liver, enzymes formed from the small intestine, and the pancreas facilitate with further digestion as well as HCI denatures (unfolds proteins) allowing them to be available to attack by digestive enzymes (also responsible in breaking down the protein). The pyloric sphincter separates the stomach from the small intestine allowing the chime to drop into the small intestine. The small intestine is the primary site for

Gulp. Your favorite food, right in front of you. Mouth watering and eyes glued to the plate. A big inhale and the smell is even better than it looks. You just cannot wait to dive in and devour it, but how does one recognize what your favorite food is by just a sniff? Or what happens after you chew and swallow that meal? Mary Roach,“America’s funniest science writer”, will take you through the gates of the digestive system and explain everything one would ever want to know and more about what happens in the depths of the alimentary canal.

Thirty seconds ago I was in my blueberry bush as a blueberry enjoying the sun, but now I am in the mouth of the human, in the process of being digested. The enzymes in the saliva started to chemically digest me, at the same time I was being mechanically torn and crushed by all thirty two teeth. Teeth are used to break down large pieces of food into smaller pieces so it is easier to digest. I was now going down pharynx and moving my way into the oesophagus. I saw the epiglottis close up as I was being pushed down, in a way called peristalsis. Peristalsis is the contraction and relaxing of muscles which push food. I continue my way down the oesophagus and find myself in contact with the gastric juices found in the stomach. The gastric juices

into the larger lower part, reducing the amount of food the stomach can hold and slowing the

As you can see, it is a tubelike structure made of muscle and lined with mucous membrane. The pharynx functions as part of the respiratory and digestive system because it is located behind the nasal cavities and the mouth. It is the structure that we refer to as the throat. It is about twelve and a half centimeters long and consists of three parts; the nasopharynx, oropharynx and the laryngopharynx. (Anatomy.tv, n.d.) The esophagus branches off of the pharynx which carries food to the stomach. Swallowing takes place in the pharynx partly as a reflex and partly under voluntary control. The tongue and soft palate pushes food into the pharynx, which closes off the trachea. The food then enters the esophagus. The esophagus is a muscular tube extending from the pharynx to the stomach. . (Mohan, 2010). It is about 25 centimeters long. The production of mucus by glands in the mucosal lining as you can see lubricates the tube to permit easier passage of food moving toward the stomach. (Thibodeau & Patton, 2008). Food is pushed through the esophagus and into the stomach by a series of contractions called peristalsis. The lower esophageal sphincter is just before the opening to the stomach. It opens to let food pass into the stomach and closes to keep it there. (Mohan, 2010).

This crus arises from the anterior longitudinal ligament overlying the lumbar vertebrae and encircles the distal esophagus in a scissorlike fashion to form a 2-cm long hiatal canal. The proximal one-third of the LES is located proximal to the diaphragm and the distal two-thirds of the sphincter is below the diaphragm and intra-abdominal. The extrinsic sphincter component of measured LES pressure is formed by the striated muscular fibers of the diaphragm. The basal tonic pressure of the LES is mainly from the esophageal components of the sphincter, and the superimposed increments in pressure during inspiration are caused by contractions of the crural diaphragm. The magnitude of the increase in pressure during inspiration is directly proportional to the force of contraction of the crural diaphragm. During tidal inspiration, the increase in GEJ pressure is much smaller than during deep inspiration. The crural diaphragm also rapidly contracts during events that increase intra-abdominal pressures (coughing, abdominal compression, and straight leg raising), thereby protecting against reflux that might occur with these increases in gastric pressure. Both the LES and crural diaphragm relax with the initiation of swallowing and the distal esophagus and LES are pulled 1 cm-2 cm upward by the contractions of the longitudinal muscles. The peristaltic wave pushes the bolus in a distal direction

Achalasia is a not visit oesophageal engine issue that influences both the body of the throat and the lower oesophageal sphincter (LES).It includes loss of ordinary peristalsis and sphincter hypertonic, and indications are incapacitating.The path physiology of the hindered peristalsis is spoken to by the dynamic degeneration and annihilation of a subpopulation of inhibitory neuronal ganglion cells of the Auerbach my enteric plexus of the throat The subsequent dependable constriction of the lower oesophageal sphincter (LES) causes stasis of nourishment inside of the oesophageal lumen until the rising intra oesophageal weight conquers the deterrent spoke to by the car dial fit and the bolus gradually travels into the stomach.The outpouring deterrent

Additionally, the jaw muscles: masseter, temporalis, medial pterygoid, and the lateral pterygoid are involved in mechanical digestion. The change of tooth size also influenced the jaw muscles’ length. The primary function of the jaw muscles is to aid the process of breaking down food into smaller particles to make food digestion more effortless. As the size of teeth decreased, the amount of

Inside your mouth is what is known as your tongue and it has the job of pushing around your food while you chew, in order to help out with the process. Once you have completely dissolved the food and are prepared to swallow what is at this point known as bolus, your tongue pushes it to the back of your throat and into the opening of your esophagus.