Digestive & Excretory System Notes

The Digestive System Digestion is the process by which the body breaks down food into smaller nutrient molecules. Breaks down food into molecules Molecules are absorbed into blood and carried through the body Wastes are eliminated

The Digestive System Upper Digestive System Mouth Chemical digestion - saliva Mechanical digestion - teeth Esophagus - peristalsis moves food to stomach

The Digestive System II. Upper Digestive System Stomach Chemical digestion Hydrochloric acid (HCl)- provides acidic Environment for pepsin to work best Pepsin- breaks down protein into amino acids

The Digestive System Upper Digestive System Stomach Mucus protects stomach lining Cells in stomach lining are quickly replaced Mechanical digestion - stomach churning

The Digestive System Lower Digestive System Small Intestine Site of chemical digestion Liver secretes bile into the small intestine Pancreas secretes enzymes that help break down starches, proteins, and fats Absorption of nutrients by villi

The Digestive System Lower Digestive System Large intestine Bacteria feed and produce vitamins for the body Water is absorbed Passes wastes (undigested food) to rectum, then anus for disposal.

Digestive System

Excretory System

Excretory System Function of the Excretory System Collect wastes produced by cells and removes the wastes from the body. Excretion-process of removing waste from the body.

Excretory System--Components Kidneys Eliminate urea, a chemical that comes from the breakdown of proteins Eliminate excess water and other waste materials Contain about a million nephrons which are filters that remove waste from blood and produce urine, the watery fluid that exits our body.

Excretory System--Components Ureters Narrow tubes that move urine from the kidneys to the urinary bladder (a sac like muscular organ that stores urine)

Excretory System--Components Urethra A small tube that sends urine out of the body

Excretory System--Other organs of excretion Lungs-the respiratory system removes carbon dioxide and some water from the body. Skin-the integumentary system removes waste by perspiration Liver-part of the digestive system and gets rid of toxins in your blood.

Excretory System A = Kidney B = Ureter C = Urinary bladder D = Urethra