Digestive System Chapter 38

Function Breaks down food into a form that can be absorbed and used by the body

Organs of the Digestive System Mouth –Teeth break food into small pieces –Saliva moistens the food Epiglottis –Flap of tissue covering the trachea –Keeps food in esophagus only

Organs of the Digestive System Esophagus –Tube from mouth to stomach –Moves food by muscle contractions Stomach –Adds pepsin that breaks down proteins –Muscles mix together until food is liquid –Wavy texture = cells constantly reproducing

Organs of the Digestive System Small Intestine –Chemical breakdown of food by enzymes –Nutrients absorbed into blood stream –Folded into tiny layers, actually ~7m long Villi –Small finger-like projections inside the SI –Increases surface area

Organs of the Digestive System Large Intestine –Removes water from solid waste –Bacteria involved in final breakdown Liver –Breaks apart fats –Stores sugars and releases them gradually Pancreas –Produces the enzymes for digestion

Vomiting Stomach contents eject from mouth Vomiting control center = brain stem Dizziness, unpleasant odors and sights, stomach cramps may trigger Excessive vomiting = dehydration, loss of vitamins

Diarrhea Frequent watery stools accompanied by cramping Large intestine fails to remove water Triggered by certain foods, bacteria, and overeating Can lead to death (dehydration) if untreated

Constipation Large intestine doesn’t move feces and too much water is absorbed Feces becomes hard and dry = painful Caused by lack of fiber/vegetables, emotions, lack of exercise

Peptic Ulcers Acid eats a hole in the stomach Caused by a bacteria (h. pylori) in the stomach Bacteria growth is triggered by acid and stress Dr. Barry Marshall = drank h.pylori to prove that it was the cause Treated with antibiotics

Crohn’s Disease Immune system attacks the intestine Results in severe cramping and diarrhea Treated with drugs and by removing pieces of the intestine Passed on genetically Disease is usually seen in females in their 20’s

Hernia Tissue from inside the abdomen bulges out through a weak spot in the muscles of the abdominal wall Tissue = abdomen (peritoneum), a loop of intestine, or fluid Caused by muscle stress and aging Treated with surgery

Lactose Intolerant Can’t digest lactose (sugar of milk) shortage of the enzyme lactase Symptoms = nausea, cramps, bloating, gas, and diarrhea, which begin about 30 minutes to 2 hours after eating or drinking foods containing lactose avoid lactose, take medications

Heartburn Acid from the stomach leaks into the esophagus Burning in the chest, sour taste in mouth, regurgitate Caused by overeating, stress, or chronic Treated with antacids (tums, pepcid)

Hepatitis A virus infection affecting the liver 3 Types: –Hepatitis A = spread through stool (contaminated food and water), not very serious –Hepatitis B = spread through infected body fluids, severe liver damage –Hepatitis C = spread through body fluids, causes liver disease, most serious

Excretory System Chapter 38

Function Rids the body of chemical wastes

Excretory System Organs Skin –Excrete salt, urea, and water as sweat Liver –Converts potentially poisonous nitrogen wastes into urea Lungs –Excrete carbon dioxide

Kidneys Removes urea (ammonia) 2 fist-sized organs along mid-back Blood travels in and out through arteries and veins Urea leaves through the ureters and is stored in the bladder until it is expelled Filtering system for the blood

Balancing Water Kidneys regulate the amount of water in blood Takes out water and puts water back in depending on the needs of the body

Kidney Dialysis Both kidneys are damaged by disease or injury Take blood out, filter it, and then put it back inside the body Very time consuming and constraining

Kidney Stones Urea in the kidneys forms stones of uric acid Caused by infection, not enough Vitamin A, not enough fluids, too much dairy Must be passed with urine (painful) or surgery

Overactive Bladder (OAB) Urinary Incontinence - loss of bladder control frequent urination, leaks, urination multiple times during the night involuntary contractions as the bladder fills surgery or medicine can repair

Chronic Kidney Disease can't remove waste or maintain the proper fluid and chemical balances in the body. waste products build up and become poisonous (toxic) to the body fatal is not treated

Urinary Retention bladder cannot empty completely or at all Still have urge to urinate Causes = blockage, nerve damage, infections, after surgery

Urinary Tract Infection bacterial infection of the urinary tract painful, frequent urination occurs mostly in women dangerous if allowed to spread through urinary system