Christian Toleration,That Submitted to: Proof. Josephine Tendon Faculty-in-charge I. Description of the system Your digestive system is uniquely constructed to perform its specialized function of turning food into energy. Each step in digestion requires energy, and thus imposes an “overhead charge” on the energy made available from absorbed substances The major part of digestion takes place in the small intestine.
The large intestine serves as the site for fermentation of indigestible matter by gut bacteria and for absorption of water from digests before excretion Mechanical and chemical digestion begins in the mouth where food is chewed and mixed with saliva to begin enzymatic processing of starches. The stomach will continues to break down mechanically and chemically through churning and mixing with both acids and enzymes. The whole digestive system is about 9 meters long II. Parts of the system 1 . Mouth Known as the “Abacas Cavity’,where food is chewed Saliva is secreted in large amounts (1-1. Liters per day) by three pairs of exocrine glands(parroted, submariner, and subliminal) in the mouth and mixed with the hewed food by the tongue Saliva cleans the mouth, moistens the food, and contains digestive enzymes such as salivary amylase. It contains mucus, it helps to soften the and tort into bolus. Swallowing transport arts the chewed t in the esophagi passing the pharynx Swallowing is coordinated by the swallowing center in the medulla obbligato and ponds 2. Pharynx Part of the neck and throat situated behind the mouth and nasal cavity, and cranial, or superior, to the esophagi.
Both part of digestive and respiratory system Epiglottis closes over trachea when food is swallowed to prevent choking or asphyxiations Orphaning is the part behind the mouth. It is lined with stratified exogamous epithelium. Misanthropy lies behind the nasal cavity and like the nasal passages is lined with ciliated columnar pseudoscience epithelium Hypnotherapy serves as a passageway for food and air and I lined with a stratified exogamous epithelium. It is continuous with the esophagi. During swallowing, food ha the “right of way’ and air passage temporarily stops. . Esophagi It is a narrow muscular tube about 20-30 centimeters long, which starts at the pharynx at the back of the mouth, passes through the thoracic diaphragm, and ends t the cardiac orifice of the stomach. At the top of the esophagi, is a flap of tissue called epiglottis that closes during swallowing to prevent food from entering trachea. The chewed food is pushed down the esophagi to the stomach through peristaltic contraction of these muscles. 4. Stomach A small J-shaped pouch with walls made of thick dismissible muscles,which stores and helps breakdown food.
Stomach churning has the effect of assisting the physical disassembly begun IM the mouth Food enters the stomach through the cardiac office where it is further broken apart and thoroughly mixed with gastric acid, pepsin and there digestive enzymes to break down proteins. The enzymes in the stomach work at a specific pH and temperature better than any others. Acid provides an optimum pH for the reaction of the enzymes pepsin and kills many microorganisms that are ingested with the food. Let can also denature proteins.
This is the process of reducing polypeptide bonds disrupting salt bridges, which in turn causes a loss of secondary, tertiary, or quarterly protein structure. The parietal cells of the stomach also secrete a globetrotting called intrinsic factor, which enables the absorption of vitamin 8-12. Mucus neck cells are present in the gastric glands of the stomach. They secret mucus, which along with gastric Juice which plays an important role in lubrication and protection of the mucosa epithelium from excoriation by the highly concentrated hydrochloric acid.
Food in the stomach is in semi-liquid form, which upon completion is known as chem. After the food consumption, digestive “tonic” and peristaltic contractions begin, which helps break down the food and move it onward. When chem. reaches the opening to the duodenum known as the pylorus, contractions “squirt” the food back into the stomach through the process called territories, which exerts additional force and further grinds down food into smaller particles. Gastric emptying is the release of food from the stomach into the duodenum;ten process is tightly controlled Witt liquids being emptied much more quickly than solids.
Gastric emptying has attracted medical interest as rapid gastric emptying is related to obesity and delayed gastric emptying syndrome is associated with diabetes mellitus, aging and gastrointestinal reflux The transverse section of the alimentary canal reveals four(or five, see description under mucosa)distinct and well developed layers within stomach: Serious membrane, a thin are of ministerial cells that is the outermost wall of the stomach Muscular coat, a well developed layer used to mix ingested food, composed of three sets running in three different alignments Subatomic, composed of connective tissue that links the inner muscular layer to the mucosa and contains nerves, blood and lymph vessels Mucosa is the extensively folded innermost layer. Let can be divided in to the epithelium, lamina Peoria, and the muscular mucosa, through some consider the outermost muscular mucosa to be a distinct layer, as it develops from the mesoderm than the endoderm . Small Intestine Has three parts:Duodenum, Jejunum, and Ileum The majority of digestion and absorption occurs here after the milky chem. enters the duodenum. Here is father mixed with three different liquids Bile-emulsifies fats to allow absorption, neutralizes the chem. and is used to excrete waste products such as billing and bile acids. T is produced by the liver and then stored in the gallbladder where it will BRB released to he small intestine via the bile duct Pancreatic Juice-made by the pancreas, which secretes enzymes such as pancreatic amylase, pancreatic peas, and transporting Intestinal Juice-secreted by the intestinal glands in the small intestine. Let contains enzyme such as antidepressant, repine, trying, chemotherapy, maltase, lactate, and sucrose. The pH level increases in the small intestine as all three fluids are alkaline. Small, finger-like structures called villa, and their epithelial cells covered with numerous microvolt to improve the absorption of nutrients by increasing the surface area of the intestine enhancing speed at which nutrients are absorbed.
The small intestine and remainder of the digestive tract undergoes resistless to transport food from the stomach to the rectum and allow food to be mixed with the digestive Juices and absorbed. 6. Large Intestine As undigested food leaves small intestine, which is shorter but much broader than the small intestine. It absorbs water and mineral salts from undigested food material. It is less vigorous in absorptive activity. It produces calculation, renews epithelial cells, and provides protective mucus and mucosa immunity. It is about 1. 5 meters long with three parts: the CACM at the junction with the small intestine, the colon, and the rectum. Food products that cannot go through the villa, such as cellulose are mixed with other waste products from the body and become hard and concentrated feces. Ill.
Processes that takes place in the system Digestion is separated into four steps: Ingestion Intake of food Mouth is responsible for its function, as it orifices through which all food enters the body. The mouth and the stomach are also responsible for the storage of food as it is waiting to be digested. Digestion Foods are broken down into nutrients. The breakdown of food into simpler substances for use by the body is the work of he digestive system. Once food is broken down into nutrients,the nutrients are carried to all the cells of the body by the blood. The nutrients in the cell are used to provide energy and the raw materials for cell growth and repair.
Absorption After food has been reduced into building blocks, it is ready for the body to absorb It begins in the stomach wit simple molecules like water and alcohol being absorbed directly into the bloodstream It takes place in the walls of the small intestine, which are densely folded to maximize the surface area in contact with ingested food Large intestine is also involved in the absorption of water and vitamins B and K before feces leave the body Excretion Also known as defecation It removes indigestible substances from the body so that they do not accumulate inside the gut. It’s timing is controlled voluntarily by the conscious part of the brain, but must be accomplished on a regular basis to prevent a backup of indigestible materials. Mixing and Movement The system uses 3 main processes to move and mix food 1 . Swallowing Process of using smooth and skeletal muscles of the mouth, tongue, pharynx to push food out of the mouth through the pharynx and into esophagi. 2.
Peristalsis It is a muscular wave that travels the length of the GIG tract,moving partially digested food a short distance down the tract It takes many waves for food to travel from the esophagi, through the stomach and intestines, and reach the GIG tract. 3. Segmentation Occurs only in the small intestine as short segments of intestine contract like hands squeezing a toothpaste tube. Helps increase the absorption of nutrients by mixing food and increasing its contact with the walls of the intestine.. IV. Diseases Disease Symptoms Causes Treatment Picture Peptic Ulcer-the most common ulcer of an area of the gastrointestinal tract that ism usually acidic thus extremely painful.