Digestive and Urinary Systems
Lesson 1
Functions of the
Digestive System

 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 of the
Digestive System

 Digestion involves both mechanical and chemical
processes
 Mechanical- chewing, mashing, and breaking food
into smaller pieces.
 Chemical- Digestive juices change the food into
simpler substances.
 The nervous system triggers the digestive process to
begin at the sight or smell of food and controls
muscles involved with digestion.
 The cardiovascular system moves the nutrients to the
cells of the body.
Ingestion

 Ingestion is the process of taking food into the body,
 3 Primary Structures involved:
 Teeth- Breaks the food into smaller pieces by chewing,
or mastication, which prepares food to be swallowed.
 Salivary glands- Produces saliva which aids in
breakdown of starches and sugars in food. It also
helps lubricate food, making it easier to swallow.
 Tongue- Forms chewed food into size and shape that
can be swallowed.
Swallowing

 As you swallow, muscular
contractions force food
into the throat (pharynx).
 The Uvula, which is a
small flap in the back of
the throat closes the nasal
passage.
 The epiglottis, another
small flap, closes the
opening to the trachea
(windpipe) to prevent
food from entering the
respiratory system.
The Esophagus

 When food is swallowed, it moves into the
esophagus, which is a muscular tube that extends
about 10 inches from the pharynx to the stomach.
 Food moves through the esophagus, stomach, and
intestines through a series of rhythmic, wavelike
muscular contractions called peristalsis.
 The esophageal sphincter sits at the junction of the
stomach and esophagus and allows food to enter the
stomach.
The Stomach

 The stomach is a hollow, saclike organ that is enclosed in
a muscular wall. These muscles allow the stomach to
expand when you eat.
 The Stomach has 3 tasks in digestion:
 Mixing foods with gastric juices
 Gastric juices are secretions from the stomach lining that
contain acid and peptin, which helps break down protein.
Mucus in the stomach lining prevent the strong acids from
digesting the stomach.
 Storing swallowed food and fluids
 The stomach holds food and liquid for further digestion
before they move into the small intestine
 Moving food into the small intestine
 As food is digested, it is converted to chyme, which is a
creamy, fluid mixture of food and gastric juices.
The Pancreas, Liver, &
Gallbladder

 Pancreas- Produces enzymes that break down fats,
carbohydrates, and proteins in food.
 Liver- Produces bile, a yellow-green, bitter fluid
important in the breakdown and absorption of fats.
 Gallbladder- Stores bile in times between meals.
 These fluids mix with other digestive juices and
chyme in the small intestine.
The Small Intestine

 About 23- 23 feet in length and 1 inch in diameter.
 The inner wall of the small intestine contains
millions of fingerlike projections called villi.
 These villi contain capillaries that collect nutrients
and carry them throughout the body through the
cardiovascular system.
 Undigested material leaves the small intestine and
enters the large intestine through peristalsis.
The Large Intestine

 The large intestine is about 5 to 6 feet in length and
about 2.5 inches in diameter.
 It’s main functions are to absorb water, vitamins, and
salts, and to eliminate wastes.
 http://www.youtube.com/watch?v=lm3oIX6jjn4
Removing Wastes From
the Body

 The body produces wastes in the forms of solids, liquids,
and gasses.
 Solid wastes are removed through the large intestine
where bacteria convert the undigested food materials into
a semisolid mass called feces. Feces are excreted through
the anus during a bowel movement.
 The skin excretes some wastes through the pores by
perspiration.
 The lungs expel carbon dioxide, a gaseous waste when
you breathe.
 Liquid wastes are filtered through the urinary system.
 http://www.youtube.com/watch?v=b20VRR9C37Q
Lesson 2
Health Behaviors and
the Digestive System

 These behaviors will help lead to a lifetime free of
digestive problems:





Eat a well balanced diet
Wash your hands before and after preparing food
Eat slowly and chew your food thoroughly
Drink at least 8 8oz. Glasses of water daily
Avoid using food as a way of dealing with stress and
emotion
Problems of the
Digestive System

 Can range from minor discomfort caused by gas or
indigestion to more serious problems that need
immediate medical attention such as appendicitis
 Problems can either be Functional or Structural
Functional Problems of
the Digestive System

 Indigestion
 Feeling of discomfort in the upper abdomen.
 Can be accompanied by gas and nausea
 Can be caused by eating too much, eating too quickly, &
spicy foods that are high in fat.
 Stomach orders and stress can lead to indigestion
 Heartburn
 Burning sensation in the center of the chest that may rise
from the tip of the breastbone up to the throat.
 Results from acid reflux, or backflow of stomach acid into
the esophagus.
 As acid enters the esophagus, it irritates the tissues, causing
a burning sensation
Functional Problems of
the Digestive System

 Hiatal Hernia
 Condition in which part of the stomach pushes through an
opening in the diaphragm.
 Persistent heartburn can be a symptom of hiatal hernia.
 Gas
 Certain amounts of gas are considered normal.
 Excessive gas can result in cramps or uncomfortable
feelings of fullness.
 Certain foods may cause excess gas in some people, but not
in others.
 Constipation
 Condition in which feces become dry and hard and bowel
movements become difficult.
 Can be caused by not getting enough fiber or water.
Functional Problems of
the Digestive System

 Nausea
 Feeling of discomfort that sometimes precedes vomiting.
 Caused by motion sickness, pathogens, some medications,
and dehydration.
 Vomiting is a reflex in which the contents of the stomach are
brought back up the esophagus and out of the mouth. This
is caused by powerful muscular contractions in the
stomach.
 Diarrhea
 Frequent passage of watery feces.
 Occurs when digested food passes too quickly through the
large intestine
 Can be cause by changes in eating style, overeating,
pathogens, or nutritional deficiencies.
 Large concern is dehydration.
Structural Problems of
the Digestive System

 Gallstones
 Formed when cholesterol in bile crystalizes and blocks the
bile duct between the small intestine and gallbladder.
 Symptoms include pain, nausea, vomiting, and fever
 Can be treated with medication, ultrasound or surgery.
 Appendicitis
 Inflammation of the appendix
 Symptoms include pain, fever, loss of appetite, nausea,
vomiting, and tenderness in the area.
 Can be a very serious problem if the appendix bursts
 Treatment includes surgical removal of the appendix.
Structural Problems of
the Digestive System

 Gastritis
 Inflammation of the mucus membrane that lines the
stomach.
 Caused by use of tobacco or alcohol, infection, and certain
medications (aspirin)
 Symptoms include pain, indigestion, decreased appetite, &
nausea and vomiting.
 Lactose Intolerance
 Cause by underproduction of enzyme Lactase, which aids
in breaking down dairy products.
 Bacteria in the small intestine ferment and cause symptoms
of abdominal cramps, bloating , gas, and diarrhea.
 People with lactose intolerance should avoid dairy products
and switch to alternate sources of calcium.
Structural Problems of
the Digestive System

 Peptic Ulcer
 A sore in the lining of the digestive tract
 Can be caused by regular use of medications (aspirin), or by
infection
 Symptoms include nausea, vomiting, and abdominal pain that
worsens when the stomach is empty.
 Cirrhosis
 Destruction of liver tissue, usually caused by prolonged and
heavy alcohol use.
 Can lead to total liver failure and death unless a liver
transplant is performed.
 Crohn’s Disease
 Causes inflammation of the linin of the digestive tract.
 Symptoms include diarrhea, weight loss, fever, and abdominal
pain.
 No known cause but has been thought to have stemmed from
immune disorders
Structural Problems of
the Digestive System

 Colon Cancer
 Second leading cause of cancer deaths in the United States
 Usually develops in the rectum and blocks the colon or causes
bleeding with elimination.
 Slow spreading- early medical help yields much higher
survival rates.
 Colitis
 Inflammation of large intestine or colon
 May be caused by bacterial or viral infection
 Symptoms include fever, abdominal pain, and diarrhea that
may contain blood
 Hemorrhoids
 Veins in the rectum and anus that are swollen as a result of
increased pressure.
 May occur with constipation, during pregnancy, and after
childbirth
 Symptoms include itching, pain, and bleeding
Lesson 3
Function of the Urinary
System

 Main function is to filter waste and extra fluid from
the body.
 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 wastes become toxic to the cells if they remain
in the body for too long.
The Kidneys

 Bean shaped organs that are about
the size of a fist near the middle of
the back, just below the rib cage.
 Remove waste products from the
blood through tiny filtering units
called nephrons.
 Each kidney contains millions of
nephrons.
 Each nephrons contains a small
ball of capillaries called a
glomerulus and a small tube
called a renal tubule that functions
as a filtering funnel.
 As part of the filtering process, the
kidneys adjust the amount of salt,
water, and other materials
excreted in the urine according to
the body’s needs.
 They monitor and maintain the
body’s acid-base and water
balances.
The Ureters

 The ureters are tubes that connect the kidneys to the
bladder.
 Each ureter is about 8-10 inches long
 Muscles in the ureter walls tighten and relax to force
urine down and away from the kidneys
 Some amount of urine is passed from the ureters and
the bladder every 15 seconds.
The Bladder and the
Urethra

 The bladder is a hollow muscular organ that acts as a
reservoir for urine.
 Located in the pelvic cavity, the bladder is held in
place by ligaments attached to other organs and the
pelvic bones.
 Until the bladder is ready to be emptied, sphincter
muscles close tightly around the opening into the
urethra.
 The urethra is the tube that leads from the bladder to
the outside of the body
Healthy Behaviors and
the Urinary System

 Drink at least 8 8oz. Glasses of water each day
 Limit the amount of caffeine and soft drinks as they
can lead to dehydration
 Eat a well balanced diet
 Practice good hygiene and personal health to avoid
bacterial infection
 Have regular medical check-ups.
 Report any changes in color, odor, or frequency of
urine elimination to a doctor as they can be warning
signs of urinary system disorders
Problems of the Urinary
System

 Can result from several different conditions, including
infection or blockage of urine.
 Cystitis is an inflammation of the bladder, most often
caused by bacterial infection, which can spread to the
kidneys
 Urethritis is the inflammation of the urethra that can be
caused by a bacterial infection.
 Symptoms of both can include burning pain during
urination, increase frequency of urination, fever, and the
presence of blood in the urine.
Kidney Problems

 Nephritis
 Inflammation of the nephrons. Symptoms include
fever, tissue swelling, and changes in urine production
 Kidney Stones
 Form when salts in the urine crystallize into stones.
Small stones can normally pass naturally but larger
ones my need ultrasound treatment in order to break
them into small pieces.
 Uremia
 Associated with decreased blood filtration by the
kidneys. Leads to abnormally high concentrations of
nitrogen which can cause tissue damage.
Kidney Failure

 Can be acute or chronic. Treatment includes
reducing symptoms and slowing progression.
 Hemodialysis
 Technique in which an artificial kidney machine
removes waste products from the blood.
 Peritoneal dialysis
 Uses a thin membrane that surrounds the digestive
organs to filter blood.
 Kidney transplant
 Involves replacing non-functional kidney with healthy
kidney from a donor.