Digestive SystemJudah Higgins, Sabrina Lam, Marybelle Panlilio, Melinda Vue, Cecilia Marin, Sam Phan

Mouth● Structure of the mouth

o Lips - Forms the entrance of the mouth, marks the transition from skin to mucous membrane

o Gums - Made up of fibrous and dense tissue lining the alveolar arches and hugs teeth

o Teeth - Helps mechanically digest food by chewing ito Tounge - Helps in tasting and swallowingo Salivary Glands - Makes saliva, keeping mouth moist and

has enzyme sot break down food● Function of the mouth

o The mouth helps break down food. Salivary glands in the mouth secrete saliva when a person smells food, and increases when a person tastes the food. In the mouth, the food begins to be broken down in small pieces, able to be digested. While this is happening, more saliva is produced in order to break down the food. The saliva helps transform the food into a bolus in order for it to be swallowed safely.

Epiglottis and Pharynx● Structure of the epiglottis

o Has a leaf-like structure attached to the anterior part of the thyroid cartilage.

● Function of the epiglottiso Folds over the glottis to block it in order to stop

food and liquid from entering the trachea (windpipe) via the intrisic and extrinsic muscles

● Structure of the pharynxo Passageway leading from the mouth and nose

to the esophagus and larynx.● Function of the pharynx

o Permits passage of swallowed solids and liquids into the esophagus, or gullet. Also conducts air to and from the trachea during respiration.

Esophagus● The esophagus is connected to the pharynx (throat) then to

the stomach. ● It is 8 inches long and lined with mucosa (pink moist tissue). ● Located behind the heart, trachea (windpipe), and in front of

the spine. ● Main functions of the esophagus’s task is to carry food,

liquids, and saliva in the mouth to the stomach to digest. ● When a person swallows food is able to travel down to the

stomach by a muscle, sphincters. ● Sphincters will relax to let food pass to the stomach and then

quickly closes to prevent food flowing from the stomach back to the mouth.

● Typically the esophagus is a food tube transporting the food to the stomach for digestion.

Stomach● The stomach is located below the diaphragm and on the

upper left abdomen. ● It has 3 regions: fundus, body, and the antrum. ● The walls of the stomach has longitudinal, circular and

oblique muscle with submucosa and mucosa in it. ● Main functions of the stomach is as a storage until

digestive enzymes act. ● In the esophageal sphincter, the stomach releases acids

and enzymes which break down the pathogen on the food. ● Then the stomach muscles periodically churn the food

enhancing digestion. ● Finally, the pyloric sphincter (a muscular valve) opens

passing the food to the small intestine to do it’s task.

Liver● The liver is found just above the stomach

and it has a wide variety of functions● One main function of the liver is releasing

two very important hormones, insulin and glucagon

● Another role that the liver plays is in digestion

● The liver grants us the ability to create bile which helps us greatly with the digestion of lipids

● The tissues that make up the liver regulate many different biochemical which breakdown of complex molecules

Gallbladder● The gallbladder is a small organ located

underneath the liver● Its job is to produce and store bile, which is

used in digestion● Within the gallbladder the stored bile is

concentrated and then later released into the small intestine

● While the bile is very important in the digestion of fats (lipids) the gallbladder is not necessary for humans to survive

● The removal of the gallbladder would show little to no effects in a healthy human

PancreasThe pancreas produces important hormones like insulin, glucagon. It also helps digest food by releasing digestive enzymes into the food tube that help receive nutrients from the food.

DuodenumWhat is the duodenum?

● The duodenum is placed in between the stomach and jejunum which is the central part of the small intestine. It’s also considered the 1st portion of the small intestine

What is the structure of the duodenum?● It’s placed very near and below stomach and its front end is very close to pancreas and liver● Anatomically it is segmented into four parts: descending, superior, horizontal and ascending

duodenum● The inner linings of this small organ comprise of crypts which increase the surface area in

the intestinal membrane. Due to this, better digestion can be achieved. It also comprise of smooth muscles which enable the flow of waste materials to large intestine

What are the functions of the duodenum?● Accepting partially digested food from the abdomen● Ensures proper digestion along with gallbladder, liver and pancreatic juices from pancreas● Controls the gastric emptying rate● Triggers off the hunger signals● When digestion process complete, it absorbs nutrients

Small IntestineWhat is the small intestine?

● It’s the section of your digestive tract where the majority of food digestion and nutrient absorption takes place

What is the structure of the small intestine?● It’s framed by the large intestine and is by far, the longest

section of your alimentary canal.● It’s divided into three sections: the duodenum, the jejunum

and Ileum and Peyer’s PatchesWhat are the functions of the small intestine?

● Absorption of nutrients and minerals● Food left undigested is sent to the large intestine

AppendixThe appendix is a vestigial organ that has no known function. It is located at the beginning of the large intestine. It is thought to possibly be what’s left of a once larger cecum.

Large Intestine● Final section of the gastrointestinal tract that performs

the vital task of absorbing water and vitamins while converting digested food into feces.

● The absorption of water allows the body to retain water to be used in other metabolic processes.

● The large intestine is about 5 feet (1.5 m) in length and 2.5 inches (6-7 cm).

● Vitamin K is produced by the gut bacteria and is essential in the proper clotting of blood. Gases such as carbon dioxide and methane are also produced as a byproduct of bacterial fermentation and lead to flatulence, or gas passed through the anus.

● Ions and nutrients released by gut bacteria and dissolved in water are also absorbed in the large intestine and used by the body for metabolism.

Large Intestine Cont.● Ascending Colon: Superior region that forms a hollow

tube that climbs along the right side of the abdomen. ● Transverse Colon: The ascending colon toward the

middle of the body at the hepatic flexure and continues across the abdomen .

● Descending Colon: At the left side of the abdomen, the transverse colon turns at the splenic flexure and runs down the left side of the abdomen.

● Sigmoid Colon: At the end of the descending colon, the large intestine bends to form the S-shaped sigmoid colon.

● Rectum: 8 inch chamber that stores the dried, condensed fecal matter,and pathway for gases to evacuate the Large Intestine.

● Anus: Last part of digestive tract that is made up pelvic floor muscles and anal sphincters. These lets us know when the contents are liquid, gas or solid and decide when is the right time to defecate.

Sources:● http://upload.wikimedia.org/wikipedia/commons/c/c5/Digestive_system_diagram_en.svg● http://www.ivyroses.com/HumanBody/Digestion/Structures-of-the-Mouth.php● http://my.clevelandclinic.org/health/ns_overview/hic-the-structure-and-function-of-the-digestive-system● http://www.newhealthguide.org/Epiglottis-Function.html● http://www.britannica.com/EBchecked/topic/1081754/human-digestive-system/45316/Pharynx● http://healthfavo.com/wp-content/uploads/2013/08/oralcavity.jpg● http://faculty.college-prep.org/~bernie/sciproject/project/humbody00/Digestion/Epiglottis/q64swallow34.jpg● http://www.drugs.com/health-guide/images/205299.jpg● http://www.webmd.com/digestive-disorders/picture-of-the-pancreas● http://www.webmd.com/digestive-disorders/picture-of-the-stomach ● http://umm.edu/programs/gi-hepatology/services/barretts/normal-function ● http://www.innovateus.net/health/what-duodenum● http://www.humanillnesses.com ● http://my.clevelandclinic.org/health/ns_overview/hic-the-structure-and-function-of-the-digestive-system● http://study.com/academy/lesson/small-intestine-anatomy-and-functions.html● http://www.ivyroses.com/HumanBody/Digestion/Function-of-the-Small-Intestine.php● http://www.webmd.com/digestive-disorders/small-intestine● http://my.clevelandclinic.org/health/ns_overview/hic-the-structure-and-function-of-the-digestive-system● http://www.webmd.com/digestive-disorders/picture-of-the-liver● http://www.webmd.com/digestive-disorders/picture-of-the-gallbladder● http://en.wikipedia.org/wiki/Pancreas