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