The Digestive System

DIGESTION

Digestive System

To Know- Digestion

• 4 Basic processes of Digestion

• Parts of Gastrointestinal Tract (GI)

• Function of organs of GI

• Know order of food from mouth to anus

• Peristalsis

• Facts

Vocabulary

• mouth esophagus

• pharynx stomach

• peristalsis liver

• pancreas small intestine

• large intestine/colonrectum

• anus epiglottis

• bolus chyme

• gallbladder

Purpose of System

• Ingestion- Eating or Drinking

Mechanical/chemical

• Digestion- Process of breaking down food

Mechanical/chemical

• Absorption- Cells obtain nutrients from food molecules

• Elimination- Undigested food leaves body

Food Processing Stages

Gastrointestinal Tract- GI25-30 feet from mouthanus

Organs of Digestive System

• Six main organs: the mouth, pharynx, esophagus, stomach, small intestine, and large intestine

• Accessory organs: salivary glands, pancreas, liver, and gallbladder

The Mouth• Mechanical

(chemical) digestion

• Lips, Cheek, Tongue, and Teeth

• Saliva Glands• Amylase- sugar

Bolus- “Ball of Food”

• Taste buds determine if food is sweet, salty, sour, or bitter. (Umami)

Pharynx• “Gone down the

wrong pipe”

• Epiglottis

Connects pharynx to stomach10 inches long

Peristalsis-contraction of muscles in GI tract.

Sphincter- where esophagus meets stomach

esophagus

sphincter

Pharynx

• The bolus, is pushed down the pharynx

• Cartilage flap, epiglottis, seals off airway to prevent food from entering.

Common Common DiseasesDiseases►Hiatal Hernia

►Gastro Esophageal Reflux Disease (GERD)

►Heartburn

►Barrett’s Esophagus

►Esophageal Cancer

A thick muscular sac, mechanical/chemical digestion

Located below diaphragm in the abdomen

Gastric Fluids Mucus- lubricates stomach Hydrochloric Acid- breaks

down food pH 1-2 Pepsin- protein breakdown

**Can hold up to 2 liters of food

Digestion Time• Water- leaves immediately

when stomach is empty

• Fruits- about 30 minutes

• Vegetables- about 30 minutes – 1 hour

• Starches- 1 hour

• Grains- 90 minutes

• Seeds and Nuts- 2-3 hours

• Dairy- 90 minutes – 4-5 hours

• Whole egg - 45 min.

• Fish - 30 min – 60 min.

• Chicken - 1½ to 2 hours

• Turkey - 2 to 2 ¼ hours

• Beef, lamb - 3 to 4 hours

• Pork - 4½ to 5 hours

Common Diseases or Disorders

• Stomach Ulcers

• Stomach Cancer or Gastric Cancer

• Gastroenteritis

• Chronic Gastritis

After stomach digestionAfter stomach digestion Chyme: a pasty mixture Pyloric Valve

Between the stomach and the small intestine Peristalsis

Absorption of nutrients

Located between the stomach and the large intestine- Chyme enters

Duodenum- beginning ph5

Jejunum- middle

illium- end

Approximately 7 meters

Small Intestine

• Longest organ in body- • 1 inch dia. 3 sections• 1, Duodenum: mixes up

chyme and enzymes- liquifies food.

• 2. Jujenum- most carbs/proteins absorbed.

• 3. iIlium- absorbs fats, water, bile salts.

• Food leaves SI, it is 90% nutrient free except water.

Small intestine • Purpose- Villa,

microvilli, soak up nutrients from food.

Pancreas

• Pancreas: helps digests carbohydrates, fats, and proteins- releasing most digestive enzymes.

• Pancreatic Amylase- Carbohydrates• Lipase- Fats• Trypsin-

– duodenum Protein

• Insulin- sugar • regulation

Liver

• Liver: 1 quart of blood/min passes through.

• Produces bile- stored in Gall Bladder

• Bile - breaks down fat,

• All blood from

• stomach/intestine filtered by liver removes toxins.

Colon- about 5 ft long diameter of 2½ inches

Removes water

Produces feces

The Large Intestine• Elimination of waste

• Ascending Colon- up

• Transverse Colon- across

• Descending Colon- down

• Sigmoid- sharp left turn

What’s in that brown stuff?

• Approx. 50% dead bacteria

• Remaining- indigestible food residue, and mucus form the bulk of matter!!!! !!!!

• The water of the bulk is absorbed.

• Peristalsis contractions = #2 out anus.

Factoids• The lifespan of a taste bud is 7-14 days.• Stomach cells live about 2-3 days • Humans make about 1.5-2 liters of spit/day• 90 percent of digestion and absorption

takes place in the small intestine.

• Stomach growling is the muscles moving around a hollow empty stomach.

• You can swallow upside down. (not recommended)

FactoidsThe average male will eat about 40-50 tons of

food during his lifetime in order to sustain a weight of 150 lbs

Food takes from 1-3 days from mouth to anus

Within the colon, a typical person harbors more than 400 distinct species of bacteria

On average, the stomach produces 2 liters of Hydrochloric Acid (HCl) daily

The liver is the largest organ in the body

Factoids

• It takes about 20 minutes for your brain to receive the “full stomach” signal.

• We burp/fart about 13 to14X daily!

To Know- Digestion

• 3 Basic processes of Digestion

• Parts of GI

• Function of organs

• Tract of food from mouth to anus

• Peristalsis

• Facts

**Be able to identify the parts of digestion.

QUIZ TIME

Are you ready?!

BibliographyBibliography• http://www.mayoclinic.com/invoke.cfm?id=DS00099• http://www.naturalways.com/toxic-gut.htm• http://www.umm.edu/digest/stomach.htm• http://digestive.niddk.nih.gov/ddiseases/pubs/barretts/• http://www.mamashealth.com/Stomach.asp• http://www.healthsquare.com/fgpd/fg4ch05p2.htm

• http://www.becomehealthynow.com/article/bodydigestive/730

• http://health.allrefer.com/health/upper-gi-and-small-bowel-series-small-intestine.html

• http://www.absoluteastronomy.com/encyclopedia/S/Sm/Small_intestine.htm

• http://www.canceranswers.com/Mouth.Cancer.html

• http://www.perio.org/consumer/2a.html

• http://www.tonguecancer.com/tongue_cancer.htm