Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
18 Cards in this Set
- Front
- Back
Digestive System
|
Made of digestive tract and the other organs associated with digestion. The digestive tract is also known as the alimentary canal. Digestion takes place from the mouth to the anus
|
|
Digestion
|
Breakdown of food into molecules the body can use
|
|
Absorption
|
movement of nutrient molecules into the blood vessels
|
|
Mechanical Digestion
|
physical tearing and grinding of food
|
|
Chemical Digestion
|
changes food particles into molecules the body can use
|
|
Mouth
|
Begin both mechanical and chemical digestion. Food is moved about by the tongue and muscles of mastication. Food is moistened by saliva that is produced in teh salivary glands. There are 32 adult teeth
|
|
Incisors
|
teeth that cut and tear
|
|
Canines
|
teeth that tear
|
|
Premolars/Molars
|
teeth that crush and grind
|
|
Salivary Glands
|
Comes in pairs.
1. Parotid glands 2. sublingual glands 3. submaxillary It lubricates food so that it moves smoothly through the digestive tract. Kills some bacteria. Begins breakdown of starch and glucose |
|
Swallowing
|
Food and saliva form a soft moist ball called a bolus. Tongue presses against hard palate and the pressure forces the bolus to the soft palate. Bolus then moves into the pharynx. The soft palate closes off the nasal cavity and the epiglottis seals off the trachea.
|
|
Esophagus
|
Once past the pharynx the food enters the esophagus. Muscular tube leading to the stomach. Food moved along by the peristalsis. One set of muscles run circular while the other runs lengthwise
|
|
Stomach
|
Esophagus ends at the cardiac sphincter, which prevents stomach contents from re-entering the esophagus. J-shaped bag like organ. Capacity of 2-4 L. Mechanical and chemical digestion.
3 Layers: circular, lengthwise, and diagonal. Peristaltic action causes mixing and grinding. Begin protein digestion. About 35 million glands produce HCl, Pepsin, and mucus. Pepsin split protein into smaller amino acids. HCl dissolves minerals and kills bacteria. Mucus protects stomach lining. Pyloric sphincter - muscular valve that controls the passage of food out of hte stomach cell layer replaces itself every 3 days. Gastroesophageal reflux - cardiac sphincter allows stomach contents to re-enter the esophagus. Peptic ulcer - too much Hcl which eats away stomach lining |
|
Small Intestines
|
where most digestion occurs. Food leaving the stomach as a semi-fluid mass is called chyme. About 23 ft in length and 1.2 in. in diameter.
Three sections: Duodenum, Jejunum, lleum. Most chemical digestion occurs in duodenum. Duodenum is protected by heavy mucus. Peptidase - break down proteins Maltase, Lactase, and Sucrase - converts disaccharides into monosaccharides. Intestinal lipase - splits fats into fatty acids and glycerol. Amino acids, monosaccharides, fatty acids, glycerol, water and minerals are quickly absorbed here. Surface covered by villi and microvilli. Absorption by diffusion and active transport. Capillaries - abstorb monosaccharides and amino acids (hydrophilic) Lacteals - absorbs fat (hydrophobic) |
|
Large Intestines
|
Minerals, water, and undigested food enter. Aka. colon. Absorption of water and minerals take place here. Three sections of the large intestine ascending, transverse, and decending. Last portion fo the large intestine is called the rectum. Ecoli (bacteria) naturally found in the large intestine and feeds on undigested food which produces some amino acids and vitamin K.
Appendix - blind sac like structure Constipation and diarrhea can result from abnormal content |
|
Pancreas
|
secrete digestive juices into the small intesine. Located behind stomach. Secrete sodium bicarbonate to neutralize acidity of chyme leaving stomach. Secrete amylase, lipase, and trypsin and chymotrypsin.
|
|
Pancreatic Enzymes
|
Amylase - breaks down carbs
Lipase - breaks down fats Trypsin and Chymotrypsin - breaks down proteins |
|
Liver
|
Largest internal organ. Produces bile which breaks fat molecules into fat droplets which will increase the surface area for lipase to work on. Bile enter duodenum from gall bladder. Gall bladder is a storage organ for bile. Fat emulsifier separates large fats from small fats
|