Digestive System
By: Morgan Jensen
The digestive system is a group of organs that work together to ensure proper digestion and absorption of nutrients.
Main Organs of the digestive System
- mouth (teeth tongue salivary glands)
- pharynx
- esophagus
- stomach
- small intestine (duodenum, jejunum, ileum)
- large intestine (vermiform appendix)
- cecum
- colon (ascending, transverse, descending, sigmoid)
- rectum
- anal canal
- liver
- gallbladder
- pancreas
Mouth
- a hollow chamber with a roof, floor, and walls
- food enters here and digestion starts right away
- teeth, tongue, and salivary glands found here
teeth and tongue
oral cavity
salivary glands
Pharynx
nasopharynx
oropharynx
laryngopharynx
Pharynx (Throat)
- tube-like structure made of muscle
- food passes through in its way to the stomach
Esophagus
- muscular, mucus lined tube that connects the pharynx with the stomach
- 25 cm long
- food travels through to get to stomach
Stomach
- lies in the upper part of the abdominal cavity
- pouch that holds food after its been chewed, swallowed, and passes through the esophagus
- contractions of the stomach walls mix food with gastric juices to break it down into chyme
Small Intestine
- 7 meters long
- 3 areas: duodenum, jejunum, and ileum
- intestinal glands secrete the intestinal digestive juice
- the products of carbs and proteins digestion get absorbed in here
small intestine
duodenum
small intestine
jejunum
ileum
small intestine
Liver
- found in the upper right section of the abdominal cavity and partially on the left side
- largest gland in the body (exocrine gland)
- the liver detoxifies chemicals and metabolizes drugs
Gall Bladder
- pear shaped, hallow structure
- stores and concentrates digestive liquid called bile that the liver makes
Gall Stones
- gall stones are solid clumps of material that form in the gall bladder
- some never cause problems and some produce painful symptoms and medical complications
- gallstones form when cholesterol concentration in bile becomes excessive causing precipitation to occur
- some symptoms are: pain in upper abdomen or back, nausea, vomiting, bloating, indigestion, or gas
- gall stones are treated with surgery sometimes otherwise they can be "passed"
Pancreas
- found behind the stomach
- it secretes panreatic juice into ducts and also secretes hormones into blood
- pancreatic juice is the most important digestive juice because it digests all three major kinds of food
Large Intestine
- about 1.5 meters long
- undigested and unabsorbed food material enters the large intestines
- it includes the cecum; ascending, transverse, descending, and sigmoid colons; rectum; and anal canal
Appendix
- worm-like, tube-like structure
- contains lymphatic tissue
- may play a minor role in the immunological defense mechanism of the body
- directly attached to the cecum
- 1 inch long
Some Digestive Juices
- saliva- digests starch
- gastric juice- digests proteins
- pancreatic juice- digests proteins, fats emulsfied by bile, and starch
- intestinal enzymes (peptidases, sucrase, lactase, maltase)- digests peptides, sucrose, lactose, and maltose
Gastroesophageal Reflux Disease (GERD)
- a set of symptoms resulting from a hiatal herniam that allows the stomach contests to flow back into the esophagus
- symptoms include: heartburn or chest pain and coughing or choking during or just after a meal
- avoid problem foods or beverages, stop smoking, or lose weight if needed to solve the problem
- acid-blocking medications may also be used to treat
Malocclusion
- abnormal contact between the teeth of the upper jaw and lower jaw
- caused by childhood habits such as sucking thumbs, pacifier use, and sucking on a bottle, extra teeth, lost teeth, impacted teeth, or abnormally shaped teeth
- symptoms include spaces between teeth, discomfort when chewing or biting, and speech problems or lisp
- treatment is braces, removal of teeth, jaw surgery, and wires or plates to stabilize jaw