Lesson 1: The Digestive System
Lesson 2: Caring for the Digestive System
Lesson 3: The Urinary System
The Digestive System

Lesson 1
Functions of the Digestive System

 The functions of the digestive system can be divided
into these three main processes:
 Digestion- the mechanical and chemical breakdown of
foods for use by the body’s cells.
 Absorption- the passage of digested food from the
digestive tract into the cardiovascular system.
 Elimination- the expulsion of undigested food or
body wastes.
Functions Continued

 The nervous system and the cardiovascular system also
play a role in digestion.
 The nervous system triggers the digestive process to
begin at the sight or smell of food and controls
muscles that move through the digestive system.
 After food is broken down, the nutrients are absorbed
into the blood and the cardiovascular system delivers
the nutrients to all cells in the body.
Structures of the Digestive System

 The digestive process begins in the mouth.
 Your teeth break the food into smaller pieces.
 Your salivary glands produce saliva- the first digestive
juices used in the digestive process.
 Your tongue forms chewed food into a size and shape
that can be swallowed.
Structures Continued

• Swallowed food enters the esophagus- the muscle
tube that connects the pharynx with the stomach.
• Peristalsis- a series of involuntary muscle
contractions that move the food through the
digestive tract.
Structures Continued

 The stomach is a hollow, saclike organ enclosed in a
muscular wall. It has three tasks in digestion.
 The stomach mixes food with gastric juices- secretions
that contain hydrochloric acid and pepsin.
 The stomach stores swallowed food and liquid.
 The stomach moves food into the small intestine.
Structures Continued

• The pancreas produces enzymes that break down the
carbohydrates, fats, and proteins in food.
• The liver produces bile- a fluid important in the breakdown and
absorptions of fats.
• The gallbladder stores bile between meals.
Structures Continued

 From the stomach, food enters the small intestine,
which is 20-23 feet long and 1 inch in diameter.
 Digestive juices from glands in the lining of the small
intestines, as well as from the pancreas and liver, are
mixed with digesting food.
 Nutrients are absorbed from the wall of the small
intestine and carried through the body by the
cardiovascular system.
Structures Continued

 Undigested parts of food pass into the colon, or large
intestine, which is 5-6 feet long and 2 ½ inches in
diameter.
 The large intestine absorbs water, vitamins, and salts.
 Solid wastes are eliminated through the large
intestine. They are formed into feces- wastes excreted
through the anus during a bowl movement.
Caring for the Digestive System

Lesson 2
Health Behaviors and the
Digestive System

 These health behaviors will help keep your digestive
system healthy:
1. Follow a well-balanced diet including a variety of foods
that are low in fat and high in fiber.
2. Wash your hands before preparing a meal and before
eating.
3. Eat slowly and chew your food thoroughly.
4. Drink at least eight, 8-ounce glasses of water each day.
5. Avoid using food as a way of dealing with your
emotions.
Health Behaviors Continued

The reward for maintaining good eating habits could be a lifetime
free of digestive problems or habits that could lead to disease.
Problems of the
Digestive System

There are several functional problems of the digestive system.
Problems Continued

 Indigestion is a feeling of discomfort in the upper
abdomen. It can be caused by eating too much,
eating to quickly, or eating foods that are spicy or
high in fat.
 Heartburn is a burning sensation in the center of the
chest that may rise from the bottom, or tip, of the
breastbone up in the throat. Frequent or prolonged
heartburn can be an indication of more serious
digestive disorders.
Problems Continued

 Excessive gas can result in cramps or an
uncomfortable feeling of fullness in the abdomen.
Foods such as beans and cabbage may cause gas.
 Constipation is a condition in which feces become dry
and hard and bowel movements are difficult.
Constipation can be caused by not consuming
enough water or fiber.
Problems Continued

• Nausea is the feeling of discomfort that sometimes precedes
vomiting.
• Diarrhea is the frequent passage of watery feces.
Problems Continued

 Structural problems of the digestive system usually
require medical attention.
 Gallstones are formed when cholesterol in bile
crystallizes and blocks the bile duct between the small
intestine and the gallbladder.
 Appendicitis is the inflammation of the appendix- a
tube about 3-4 inches long that extends from the
beginning portion of the large intestine.
Problems Continued

 Gastritis is an inflammation of the mucus membrane
that lines the stomach.
 Lactose intolerance involves an inability to digest
lactose, which is a type of sugar found in milk and
other dairy products.
 A peptic ulcer is a sore in the lining of the digestive
tract.
Problems Continued

 Cirrhosis is scarring of the liver tissue. It is usually
caused by prolonged and heavy alcohol use.
 Crohn’s disease causes inflammation of the lining of
the digestive tract.
 Cancer of the colon and rectum is the second leading
cause of cancer deaths in the United States.
Problems Continued

 Colitis is an inflammation of the large intestine or
colon.
 Hemorrhoids are veins in the rectum and anus that are
swollen as a result of increased pressure.
 Tooth decay is a problem with the digestive system,
because teeth are very important in the digestive
process.
The Urinary Sytem

Lesson 3
Function of the Urinary System

The main function of the urinary system is
to filter waste and extra fluid from the blood.
Function Continued

• Urine is liquid waste material excreted from the body through
the process of urination.
• Urine consists of water and body wastes that contain nitrogen.
• These body wastes become toxic to cells if they remain in the
body for too long.
Function Continued

 Kidneys are bean-shaped organs about the size of a
fist.
 Kidneys are located near the middle of the back, just
below the rib cage
 They remove waste products from the blood through
tiny filtering units called nephrons.
Function Continued

 Ureters are tubes that connect the kidneys to the
bladder.
 The bladder is a hollow muscular organ that acts as a
reservoir for urine.
 The urethra is the tube that leads from the bladder to
the outside of the body.
Health Behaviors and
the Urinary System

Proper urinary function is important because wastes that are not
removed from the body quickly become toxic.
Health Behaviors Continued

 These health behaviors will help you keep your
urinary system healthy:
1. Drink at least eight 8-ounce glasses of water each day,
and limit your intake of caffeine and soft drinks.
2. Eat a well-balanced diet.
3. Practice good hygiene and personal care.
4. Have regular medical checkups.
Problems of the Urinary System

Kidney disorders should be monitored by a health professional.
Problems Continued

 Nephritis is the inflammation of the nephrons.
 Kidney stones form when salts in the urine crystallize
into solid stone.
 Uremia is a serious condition associated with a
decrease in blood filtration by the kidneys.
Problems Continued

 Kidney failure can be:
 acute- having a sudden onset.
 chronic- involving a progressive los of kidney
function.
Problems Continued

 Kidney damage may require one of these forms of
treatment:
1. Hemodialysis is a technique in which an artificial
kidney machine removes waste products from the
blood.
2. Peritoneal dialysis uses peritoneum- a thin membrane
that surrounds the digestive organs, to filter blood.
3. Kidney transplant involves the replacement of a
nonfunctional kidney with a healthy kidney from a
donor.