Date post: | 31-Oct-2014 |
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Health & Medicine |
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Digestive System
Digestive System
Digestive System - breakdown food to facilitate effective transport of nutrients to different parts of the body to be used for energy and other body functions
Digestive tract - is also called alimentary canal, alimentary tract or gastro-intestinal tract
Digestive Tract
Mouth and Teeth
Mouth - where mechanical breakdown occurs
Teeth - tear food into several pieces *Mastication - action of chewing or
grinding food
Mouth and Teeth
Subparts: Incisors, Canines - bite and tear down food Molars - grind food Parotid, Submandibular, Buccal - salivary
gland, secrete saliva Enzymes/Excretions: Amylase - digests carbohydrates Residue: No residue yet; Food
Pharynx and Esophagus
Pharynx/throat - where food is placed after swallowing
Esophagus - conveyor of food from pharynx to the stomach
*Peristalsis movement - tiny, rhythmic, wavelike contractions
Pharynx and Esophagus
Subparts: Enzymes/Excretions: Mucin - lubricate esophagus Residue: Masticated food
Stomach
Stomach - principal organ of digestion Subparts: Pylorus - where chyme passes Pyloric sphincter - where chyme exits
the stomach and enters small intestine
Stomach
Enzymes/Excretions: *Gastric juice Hydrochloric acid - activator of
pepsinogen, destroy microorganisms Zymogen - inactive form of proenzyme Pepsinogen - inactive form of pepsinogen Mucin - protect stomach lining Residue: Chyme
Small Intestine
Small intestine - where most of the nutrients are absorbed
Subparts: Duodenum - produce enzyme that signals
pancreas and liver to release its secretion Jejunum - where absorption mainly takes place Ileum - where Vitamin B12 and bile is being
absorbed Villi - increase surface area for absorption Pancreas - secretes glucagon and insulin
Small Intestine
Enzymes/Excretions: Lipase - digests fats and oils Glucagon - raises the amount of sugar Insulin - lowers down amount of sugar Somatostatin - inhibits production of
more enzymes Residue: Chyme
Large Intestine
Large intestine/colon - where water is absorbed
Subparts: Caecum, Ascending colon, Transverse
colon, Descending colon, Sigmoid colon - parts of large intestine
Enzymes/Excretions: Residue: Feces
Rectum and Anus
Rectum - where feces is stored *Bowel movement - rectum expands to
hold the feces until nerves around tell the brain that we have to push it out of our body.
Anus - where feces/bowels exit our body Subparts: Enzymes/Excretions: Residue: Feces
Types of Digestion
Physical digestion Chemical digestion
Processes of Digestion
Ingestion Absorption Assimilation Excretion
Carbohydrates
Carbohydrates
-monosaccharides: glucose, fructose -dissaccharides: lactose, sucrose,
maltose -polysaccharides: glycogen, starch,
cellulose Enzyme: -amylase: lactase, sucrase, maltase
Carbohydrates
Place of digestion: -mouth (salivary gland releases
salivary amylase) -small intestine (pancreas releases
pancreatic amylase) After digestion: -stored in the liver to be used as
energy for all body processes in the cells, tissues and organs
Proteins
Proteins
-amino acids Enzyme: -pepsinogen that becomes pepsin -trypsinogen that becomes trypsin
Proteins
Place of digestion: -stomach (releases pepsinogen,
activated by HCl to become pepsin) -duodenum (pacreas releases
trypsinogen) After digestion: -become components of hair, skin,
eyes, muscles, body organs and connective tissues
Lipids
Lipids
-fats, oils, triglycerides Enzyme: lipase, bile Place of digestion: -mouth (salivary gland releases lingual
lipase) -small intestine (pancreas releases
pancreatic lipase) After digestion: -it will serve as stored energy