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The Digestive System. Function: Breaks down foods into simpler molecules that can be absorbed and used by the cells of the body. The Digestive System. Structures. Organs: mouth, pharynx, esophagus, stomach, small intestine, and large intestine.
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Function: Breaks down foods into simpler molecules that can be absorbed and used by the cells of the body. The Digestive System
Structures • Organs: mouth, pharynx, esophagus, stomach, small intestine, and large intestine. • Accessory glands: salivary glands, pancreas, and liver
Types of Digestion • Mechanical- grinding and crushing the food into smaller pieces that are easier to process. (example: teeth & chewing) Causes a physical change • Chemical- enzymes (specialized proteins) breaking to food down into simpler molecules your cells can use. Causes a chemical change
The mouth is where the digestive system begins. Mechanical and chemical digestion occur here. Teeth tear and crush food Mouth
Mouth, cont. Salivary glands release saliva into the mouth that contains enzymes like amylase to break down starches into sugars.
Bolus (food ball) passes from mouth through the pharynx into the esophagus Peristalsis- smooth muscles contract, pushing food down to the stomach. Pharynx Esophagus
Continues both mechanical and chemical digestion Smooth muscle churns and mixes food to produce chyme HCl makes it acidic Stomach: Structure/Fxn.
Chemical Digestion- Enzymes Enzyme Activity #1
Duodenum, jejunum, ileum (together= 6 m) More enzymes Absorption occurs on the villi, which are lined with capillaries Small intestine: Absorption
Large Intestinea.k.a. colon • Absorption of water • If too little is absorbed = diarrhea • If too much is absorbed = constipation • Unabsorbed material passes through rectum, then anus
Pancreas- VERY important fxns. Regulate blood sugar (diabetes) Produces several enzymes Produces sodium bicarbonate—a base Why is this important? Liver- produces bile which is then stored in the gall bladder Accessory Digestive Organs
Structures: skin, lungs, kidneys, ureters, urinary bladder, urethra • Function: Remove waste products The Excretory System
Primary organs of the excretory system. Remove waste products from the blood Maintain blood pH Regulate water content of the blood Waste is excreted as urine. The Kidneys
The kidneys, cont. • Located on either side of the spinal column near the lower back.
The functional units of the kidney are called nephrons. Each nephron is a small,independent processing unit. Function:As blood enters a nephron through the inpurities are filtered out and emptied into the collecting duct. Nephron Unit
The kidneys are the master chemists of the blood supply.In dialysis,blood is removed from the body through a tube inserted in the arm and pumped through special tubing that acts like nephrons. Dialysis/Homeostasis by Machine
Urine (waste) flows from the kidneys thru the ureters to the bladder where it is stored. Then, urine passes from bladder thru the urethra to exit the body The Bladder