NOTES – DIGESTIVE SYSTEM ANATOMY

Within 2-6 hours, all food is emptied into the small intestine.

After you eat how long does it take for the stomach to empty?

Interesting Digestive System Facts

1,100

How many pounds of food does the average person eat in a year?

about 20-30 ft long.

How many feet long are your intestines?

NOTES – DIGESTIVE SYSTEM ANATOMY

• Oral Cavity • mouth, pharynx, esophagus

• MOUTH • SALIVARY GLANDS – produce saliva

• Saliva Components

• Mostly water – about 99.5%

• SALIVARY AMYLASE – digests starch• LYSOZYME – antibacterial action• MUCIN – lubricant

• chewing and saliva with food form a BOLUS

• PHARYNX

• Epiglottis • prevents food from entering the trachea (wind pipe)

• common area for food and air

• ESOPHAGUS

• transports bolus from pharynx to stomach

• involuntary muscular movement of food - PERISTALSIS

• STOMACH • a storage & mixing chamber

• secretions • mucus

• hydrochloric acid (HCl)• HCl activates pepsinogen to pepsin which is main enzyme that digests protein

• movement • mixing waves - peristalsis

• bolus becomes chyme

• SMALL INTESTINE

• parts: duodenum, jejunum, ileum

• Function: • digestion and absorption

• intestinal juice – water & mucus• epithelial cells have digestive enzymes to digest ALL classes of food

• LIVER • performs many functions – main blood filter in digestive system

• in digestion it secretes BILE into the gall bladder

• the gall bladder then dumps bile into small intestine

• bile EMULSIFIES fats – breaks fat into smaller pieces – easier for fat digesting enzymes to do their work

Normal liver

fatty liver Cirrhosis of the liver

• PANCREAS

• pancreatic enzymes are important for the digestion of all major classes of food• four enzymes and bicarbonate• all are dumped into small intestine

• LARGE INTESTINE

• Parts: ascending colon, transverse colon, descending colon, sigmoid colon

• chyme is converted to feces• absorption of water & salts• E. coli bacteria synthesizes vitamin K