T H E J O U R N E Y O F D I G E ST I V E S Y S T E M - Y O U T U B E

THE DIGESTIVE SYSTEM

I. OVERVIEW

* break down food into small molecules that can be ABSORBED and used by cells in the body

* ALIMENTARY CANAL is 9 m long

II. MOUTH

* MECHANICAL & CHEMICAL digestion

* enzymes in saliva (ex. AMYLASE breaks down starch)

* BOLUS - ball of chewed food

III. ESOPHAGUS

* PERISTALSIS moves food by muscle contractions (contract & relax)

IV. STOMACH

* PEPSIN, HCl acid, & mucus – CHEMICAL digestion

* PROTEIN DIGESTION STARTS HERE!!! (add this)

* CHYME – THIN, SOUPY LIQUID

V. SMALL INTESTINE

* covered w/ VILLI (fingerlike projections lined with capillaries; increases SURFACE AREA)

* nutrients absorbed INTO BLOOD (CARBS & PROTEINS)

* JEJUNUM, duodenum, & ileum

VI. LARGE INTESTINE

* water, cellulose, & other UNDIGESTABLEsubstances left behind

* WATER reabsorbed & VITAMINS absorbed

* NO DIGESTION TAKES PLACE!!!

* FECES formed – stored in RECTUM - eliminated through ANUS

VII. ACCESSORY ORGANS

A. PANCREAS* pancreatic juice w/ENZYMES

(pancreatic DUCT delivers to small intestine)

* neutralizes STOMACH ACID

B. LIVER* produces BILE (breaks down fats)

C. GALLBLADDER* stores BILE

My X Ray swallows – YouTube

Peristaltic Wave in the Gastric Antrum – YouTube

Peristalsis... what your insides do that you can't see – YouTube

Peristalsis after a PB &J sandwuch - YouTube

THE EXCRETORY SYSTEM

I. OVERVIEW 

* maintain HOMEOSTASIS by removing WASTE products from the BLOOD, regulate blood VOLUME, & maintain pH

 

I. SKIN

* excrete SWEAT – water, salts, UREA

UREA???

* produced when the liver breaks down protein * average person excretes about 30 grams of

urea a day, mostly through urine, but a small amount is also secreted in perspiration

* one million pounds of urea is manufactured in the U.S. each year, most of it used in fertilizers

* used commercially and industrially to produce some types of plastics, animal feed, glues, toilet bowl cleaners, dish washing machine detergents, hair coloring products, pesticides, and fungicides

II. LUNGS

* excrete CARBON DIOXIDE

III. KIDNEYS

* blood cleaned & FILTERED (every 45 min. all blood)

* URINE = urea, water, & other waste* made up of millions of NEPHRONS

- filtration, REABSORPTION, secretion

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UROPHAGIA (ewww…gross!!!)

* Urophagia is the consumption of urine* Urine, which consists almost entirely of water, is

completely sterile when it leaves the body.* auto-urine therapy is said to boost the immune

system, cure migraines and other chronic conditions, stave off a cold and work wonders on eyesight problems; can work wonders on skin conditions, such as eczema or psoriasis; can apply it directly for athlete's foot, bee stings and jellyfish stings; you can gargle it for toothache and gum disease.

* Bacterial infections of the urinating person's urethra, or disease in the person urinating may pose a risk.