digestive system by Emily Alcaraz

1. digestive system

ea13357 — 2024-11-15 16:10:10 UTC

The digestive system, also known as the gastrointestinal system, is responsible for the physical and chemical breakdown of food so that it can be taken into the bloodstream and used by body cells and tissues. The system consists of the alimentary canal and accessory organs.

2. alimentary canal

ea13357 — 2024-11-15 16:11:21 UTC

The alimentary canal is a long, muscular tube that begins at the mouth and includes the mouth (oral cavity), pharynx, esophagus, stomach, small intestine, large intestine, and anus.

3. mouth

ea13357 — 2024-11-15 16:13:31 UTC

the mouth, also called the buccal cavity, receives food as it enters the body. While food is in the mouth, it is tasted, broken down physically by the teeth, lubricated and partially digested by saliva, and swallowed.

4. teeth

ea13357 — 2024-11-15 16:14:36 UTC

The teeth are special structures in the mouth that physically break down food by chewing and grinding. This process is called mastication.

5. tongue

ea13357 — 2024-11-15 16:16:01 UTC

The tongue is a muscular organ that contains special receptors called taste buds. The taste buds allow a person to taste sweet, salty, sour, and bitter sensations, in addition to a fifth taste, umami, that detects meaty or savory sensations. The tongue also aids in chewinng and swallowing food.

6. hard palate

ea13357 — 2024-11-15 16:17:09 UTC

The hard palate is the bony structure that forms the roof of the mouth and separates the mouth from the nasal cavities.

7. soft palate

ea13357 — 2024-11-15 16:18:46 UTC

Behind the hard palate is the soft palate, which separates the mouth from the nasopharynx. The uvula, a cone-shaped muscular structure, hangs from the middle of the soft palate. It prevents food from entering the nasopharynx during swallowing.

8. salivary glands

ea13357 — 2024-11-15 16:21:28 UTC

Three pairs of salivary glands, the parotid, sublingual, and submandibular, produce a liquid called saliva. Saliva lubricates the mouth during speech and chewing and moistens food so that it can be swallowed easily. Saliva also contains an enzyme called salivary amylase, formerly known as ptyalin. Salivary amylase begins the chemical breakdown of carbohydrates, or starches, into sugars that can be taken into the body. After the food is chewed and mixed with saliva, it is called a bolus.

9. pharynx (throat)

ea13357 — 2024-11-15 16:23:37 UTC

When the bolus is swallowed, it enters the pharynx (throat). The pharynx is a tube that carries both air and food. It carries the air to thhe trachea, or windpipe, and food to the esophagus. When a bolus is being swallowed, muscle action causes the epiglottis to close over the larynx, preventing the bolus from entering the respiratory tract and causing it to enter the esophagus.

10. esophagus

ea13357 — 2024-11-15 16:25:55 UTC

The esophagus is the muscular tube dorsal to (behind) the trachea. This tube receives the bolus from the pharynx and carries the bolus to the stomach.

11. peristalsis

ea13357 — 2024-11-15 16:27:40 UTC

The esophagus, like the remaining part of the alimentary canal, relies on rhythmic, wavelike, involuntary movement of its muscles called peristalsis to move the food in a forward direction.

12. stomach

ea13357 — 2024-11-15 16:29:55 UTC

The stomach is an enlarged part of the alimentary canal. It receives the food from the esophagus. The mucous membrane lining of the stomach contains folds, called rugae. These disappear as the stomach fills with food and expands. The cardiac sphincter, a circular muscle between the esophagus and stomach, closes after food enters the stomach and prevents food from going back up into the esophagus.

13. small intestine

ea13357 — 2024-11-15 16:31:39 UTC

The small intestine is a coiled section of the alimentary canal. It is approximately 20 feet in length and 1 inch in diameter, and is divided into three sections: the duodenum, the jejunum, and the ileum.

14. duodenum

ea13357 — 2024-11-15 16:35:04 UTC

The duodenum is the first 9-10 inches of the small intestine. Bile (froom the gallbladder and liver) and pancreatic juice (from the pancreas) enter this section through ducts, or tubes.

15. jejunum

ea13357 — 2024-11-15 16:35:51 UTC

The jejunum is approximately 8 feet in length and forms the middle section of the small intestine.

16. ileum

ea13357 — 2024-11-15 16:37:32 UTC

The ileum is the final 12 feet of the small intestine, and it connects with the large intestine at the cecum. The circular muscle called the ileocecal vavle separates the ileum and cecum and prevents food from returning to the ileum.

17. large intestine

ea13357 — 2024-11-15 16:40:19 UTC

The large intestine is thhe final section of the alimentary canal. It is approximately 5 feet in length and 2 inches in diameter.

Functions include absorption of water and any remaining nutrients; storage of indigestible materials before they are eliminated from the body; synthesis (formation) and absorption of some B-complex vitaminns and vitamin K by bacteria present in the intestine; and transportation of waste products out of the alimentary canal.

The large intestine is divided innto a series of connected sections. The cecum is the first section and is connected to the ileum of the small intestine.

18. vermiform appendix

ea13357 — 2024-11-15 16:41:26 UTC

vermiform appendix - small projection in the cecum

19. rectum

ea13357 — 2024-11-15 16:42:43 UTC

The rectum is the final 6-8 inches of the large intestine and is a storage area for indigestibles and wastes. It has a narrow canal, called the anal canal, which opens at a hole, called the anus.

20. anus

ea13357 — 2024-11-15 16:43:53 UTC

Rectum has a narrow canal, called the anal canal, which opens at a hole, called the anus. Fecal material, or stool, the final waste product of the digestive process, is expelled through this opening.

21. liver

ea13357 — 2024-11-15 16:46:53 UTC

The liver is the largest gland in the body and is an accessory to the digestive system. It is located under the diaphragm and in the upper right quadrant of the abdomen.

The liver secretes bile, used to emulsify fats in digestive tract. Bile also makes fats water solublle, necessary for absorption. Liver stores sugar in form of hlycogen. liver also stores iron and certain vitamins. Produces heparin, prevents clotting of blood, blood proteins, and cholesterol. Liver detoxifies (render less harmful) substances such as alcohol and pesticides, and destroys bacteria that have been taken intoo the blood from the intestine.

22. gallbladder

ea13357 — 2024-11-15 16:48:21 UTC

The gallbladder is a small, muscular sac located under the liver annd attached to it by connective tissue. It stores and concentrates bile, which it receives from the liver. When bile is needed to emulsify fats in the digestive tract, the gallbladder contracts and pushes the bile through the cystic duct into the common bile duct, which drains into the duodenum.

23. pancreas

ea13357 — 2024-11-15 16:49:53 UTC

The pancreas is a glandular organ located behind the stomach. It produces pancreatic juices, which contains enzymes to digest food. Juices enter duodenum through pancreatic duct.

24. colon

ea13357 — 2024-11-15 16:52:06 UTC

colon has several divisions. Ascending colon- continued up on right side of the body from the cecum to lower part of liver. Transverse colon- extends across abdomen, below liver and stomach and above small intestine. Descending colon- extends down thee left side of body. Connects with sigmoid colon- S shaped section that joins with the rectum

25. villi

ea13357 — 2024-11-15 16:53:27 UTC

These are found in the small intestine's inner walls. Functions: Villi enhance the absorption surface area. The blood vessels of the villi transport ingested food to every cell in the body, where it is used to obtain energy, develop new tissues, and repair damaged ones.