Chapter 22 The Digestive System Flashcards
When food and beverage in a digestive tract via the mouth
Ingestion
The muscular tube through which food passes begins with the mouth and continues through the oral cavity, pharynx, esophagus, stomach, small intestine, and large intestines which opens to the exterior anus
Gastrointestinal tract (alimentary canal)
Chewing, mixing of food with salvia, churning of food in the stomach
Mechanical processing
The mechanical processing in the intestine is called?
Segmentation
Movement of food through the Alimentary canal by swallowing and peristalsis
Propulsion
The chemical and enzymatic breakdown of food into small organic molecules that can be absorbed
Chemical digestion
Emission of water, enzymes, buffers, and acid into the lumen
Secretion
Movement of small organic and products and other important molecules such as water, electrolytes, vitamins, and minerals… From the lumen of the G.I. tract into the interstitial fluid’s,blood, or lymph
Absorption
The progressive dehydration of indigestible materials and organic waste prior to elimination from the body
Compaction
The elimination of feces via the anus
Defecation
The inner most lining containing the mucous membrane of epithelial tissue supported by a basement membrane and thin layer of muscle tissue
Mucosa
Epithelium Found in the oral cavity, pharynx, the upper portion of the esophagus, and rectum
Stratified squamous epithelium
Epithelium found within the lower portion of the esophagus, stomach, small intestine, and most of the large intestine possess numerous goblet cells and mucus producing cells… For absorption of water and electrolytes, no villi no plicae circularis, no enzyme secreting cells
Simple columnar epithelium
Composed of Areolar connective tissue, contains blood vessels, sensory nerve endings, lymphatic vessels, scattered areas of lymphoid tissue (Peyer’s patches and MALT), and mucous glands
Lamina propria
Two concentric layers of smooth muscle, the inner layer encircles the lumen (circular layer) and the outer layer runs parallel to the long axis of the G.I. tract (longitudinal layer)… Create the folds that project from the internal surface of the G.I. tract such as rugae, plicae circularis, and villi
Muscularis mucosae
A layer of dense irregular connective tissue surrounding the Mucosa… Contains large blood vessels, lymphatic vessels, nerves and in some regions exocrine glands that secrete enzymes and buffers into the lumen of the G.I. tract
Submucosa
Dominated by smooth muscle oriented into layers in inner circular layer and in outer longitudinal layer. These layers are essential in the mechanical processing of food and the propulsion of food through the digestive tract
Muscularis externa
These cells are present in areas where peristalsis or rhythmic contraction is necessary
Pacesetter cells
Along most portions of the organs in the peritoneal cavity the muscularis externa is covered by a layer of visceral peritoneum called? Hint… The outermost layer below the diaphragm
Serosa
A dense network of collagen fibers form a sheath called? Anchor the organs to the surrounding tissues hint…above the diaphragm
Adventitia
In the abdominal cavity the serosa often pulls away from the surface of the organs to create an important membrane such as the? Holes approximately 20 feet of intestines into a tight mass
Mesenteries
Located in the fundus and body, secrete most of the stomach juices used for gastric digestion, and they are dominated by several types of cells… Chief, parietal, and G cells
Gastric glands
Hormone, increase stomach motility and churning and stimulates the release of HCI from parietal cells
Gastrin
Inhibits stomach motility and emptying
Somatostatin
Secrete hydrochloric acid for activating the pepsinogen and intrinsic factor which is important in the absorption of vitamin B 12
Parietal cells
Secrete the inactive enzyme pepsinogen, which when activated to form pepsin and can begin the process of protein digestion
Chief cells
Materials arriving from the ileum through the ileocecal valve collects and stores material from the ileum and begins the process of compaction… Hint: expanded sac-like region
Cecum
Synthesizes vitamin B5, biotin and most of the vitamin K that the liver requires to make blood clotting proteins, bacteria produce several compounds that contribute to the odor of feces including ammonia
Bacterial flora
Liver cells that produced bile and process nutrients
Hepatocytes
An important emulsifier (produced by the liver and stored and concentrated by the gallbladder until needed)
Bile
