Download the digestive system

THE DIGESTIVE SYSTEM
HEALTH TERMS:
Digestion: the mechanical and chemical breakdown of foods for body’s cell
Absorption: the passage of digested food from digestive tract into circulatory system
Elimination: the expulsion of undigested food or body wastes
Ingestion: the taking of food into the body—earliest stage of digestion
Mastication: the process of chewing
Peristalsis: a series of involuntary muscular contractions that move food through the
digestive tract
Gastric Juices: secretions from the stomach lining that contains pepsin & hydrochloric
acid
Chyme: a creamy fluid mixture of food and gastric juices
Bile: a yellowish-greenish bitter fluid important in breakdown of fats- excreted from the
liver
Villi: finger-like projections that line the small intestine that aid in peristalsis & contain
Capillaries that extract nutrients from chyme
Indigestion: burning discomfort in upper abdomen—heartburn
Appendicitis: inflammation of the appendix
Peptic Ulcer: sore in the lining of the digestive tract
FUNCTIONS of the DIGESTIVE SYSTEM:
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Digestion
o Breakdown of food
 Mechanical
 Chemical
Absorption
o Nutrients occurs in the Small Intestines
 By way of the villi
o Any leftover fluid/ moisture occurs in the Large Intestines
Elimination
o Any food not broken down exits as waste (Poop)
STRUCTURE of the DIGESTIVE SYSTEM:
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Path of Food
o Mouth
 Ingestion- taking of food into the body
 Digestion begins
o Teeth
 Responsible for the mechanical breakdown of food
 Mastication- the process of chewing
 Prepares the food to be swallowed
o Salivary Glands
 Responsible for the chemical breakdown of food
 Secretions of watery fluid that contains enzymes to soften and
moisten food
 Converts carbohydrates to soluble form of sugar
o Tongue
 Forms food into a ball (bolus) to prepare for swallowing
 Responsible for wave-like motions that begin process of
swallowing
o Uvula
 Flap of skin suspended from the back of your mouth
 Closes over nasal passage when swallowing
o Epiglottis
 Flap of tissue that covers the trachea
 Closes to keep food from entering the respiratory system
o Esophagus
 Muscular tube that extends from the pharynx to the stomach
 Situated behind the trachea and the heart
 ~10 inches long with two sphincter muscles- one on each end
 Peristalsis- a series of involuntary muscular contractions- moves
food through the digestive tract- starts in the esphogus
o Stomach
 Hollow, saclike organ enclosed in a muscular wall
 Consists of three layers of muscles
 Continues the breakdown of Food
 Serves as a storage organ for food until it is ready to enter sm.
Intestine
 Mixes food with gastric juices
 Called Chyme
 Pepsin & hydrochloric acid
o Pepsin- enzyme that breaks down protein
o Hydrochloric acid- kills bacteria & creates
environment for Pepsin to do its work
o Mucous lining inside stomach protects organ from
digesting itself
o Small Intestine
 Major part of digestion and absorption occurs here.
 20-23 feet long, and 1 inch in diameter
 Consists of three parts
 Duodenum- Entrance for Chyme to the sm. intestine
 Jejunum- absorption takes place
 Ileum- opens into the large intestine
 Chyme takes 3-5 hours to move through Sm. Intestines
 Lined with millions of villi- fingerlike projections that absorb
digested food particles to deliver nutrients to the body through the
blood.
o Large Intestine
 Unabsorbed material leaves the small intestine in the form of liquid
and fiber into the large intestine.
 A.K.A. colon
 5-6 feet long, and 2.5 inches in diameter
 Movement of undigested material is very slow.
 Absorbs water back into the body to maintain hydration
 Home to harmless bacteria that changes the consistency of waste
material to semi-solid—called feces
 Elimination of feces occurs through the rectum/ anus.
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Organs that Aid Digestion
o Liver
 Second largest organ in your body
 Acts as body’s chemical factory
 Regulates the levels of most chemicals in your blood
 Absorbs substances, changes their chemical structure, makes them
water soluble
 Excretes changed substance in Bile- yellowish-green, bitter fluid
important in breakdown of fats
o Gall Bladder
 Storage organ for bile
 Small, pear-shaped sac—3-4 inches long, located under the liver
 Releases bile into the small intestine to aid in breakdown of fat.
o Pancreas
 Also a part of the endocrine system (it is considered a gland)
 Produces hormone Insulin, to regulate blood sugar.
CARE of the DIGESTIVE SYSTEM:
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Eat a Variety of Foods
Avoid Fried foods
Choose foods low in fat and high in fiber
Do not hurry through meals
Do not wash food down with liquid—swallow first, then take a sip
Drink plenty of water.
Do not eat while under stress.
PROBLEMS of the DIGESTIVE SYSTEM:
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Functional Problems
o Indigestion
 Burning discomfort in the upper abdomen
 Accompanies buildup of gas and nausea
 Caused by eating too much, eating too fast, eating certain foods,
stomach disorders, or stress
o Heartburn
 Burning pain in the center of the chest
 AKA acid reflux
 Caused by weak sphincter muscle that connects the esophagus and
stomach—irritating stomach acids overflow into the esophagus
causing burning sensation
o Gas
 Excess gas in the system
 Causes discomfort due to certain foods
o Nausea
 Feeling of distress, fullness and weakness and often precedes
vomiting
 Caused by motion, pathogens, medicines, drugs, or other
substances in the stomach
 Vomiting is a reflex response that provides a built-in protection in
case one swallows a foreign substance
 Vomiting is result of reverse peristalsis
o Diarrhea
 Condition in which feces are watery and are expelled frequently
 Food residue passes too quickly through the large intestines,
keeping the large intestine from absorbing enough water
 Causes include change in eating style, food poisoning, overeating,
emotional turmoil, nutritional deficiencies, viral and bacterial
infections.
 Remain hydrated.
 Medical help may be necessary
o Constipation
 Condition in which feces become hard and dry.
 Bowel movements are difficult
 Too much water is absorbed in the large intestines
 Caused by lack of fiber, erratic eating habits, drinking too little
water, or lack of exercise.
 Remain hydrated
 Medical help may be necessary
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Structural Problems
o Gallstones
 Small crystals that form in the gallbladder when an upset occurs in
the chemical composition of the bile
 Can possibly block the bile duct to the sm. Intestines causing back
pain
 If there is no pain, they can be left alone; or can be treated with
medicine that dissolve them
 When pain is severe, stones can be shattered with ultrasound
shock-wave, or gallbladder can be surgically removed
o Appendicitis
 Inflammation of the appendix (3-4 inch extension of the large
instestine)
 When bacteria or foreign matter lodges in the appendix it becomes
blocked, swollen & fills with puss
 If appendix ruptures, infection spreads into the abdomen—
extremely serious—sepsis occurs (poisoning)
 Symptoms include pain and cramps in lower right quadrant of the
abdomen, fever, loss of appetite, nausea, and vomiting
 Medical care is necessary—surgical removal of appendix

o Gastrititis
 Most common disorder of the digestive system
 Inflammation of the mucous membrane that lines the stomach
 Caused by irritation from certain foods, asprin, tobacco smoke,
alcohol or by bacterial infection
 Medication may be prescribed—something that coats the stomach
o Lactose Intolerance
 Inability for small intestine to produce enzyme, Lactase, that
breaks down the Lactose sugar
 Abdominal cramps, bloating, gas and diarrhea result from
undigested, fermented Lactose
 Avoid Dairy foods; however fermented milk products i.e. yogurt
can be eaten without a problem
o Peptic Ulcer
 A sore in the lining o f the digestive tract
 Factors that increase risk of ulcer include regular use of asprin,
ibuprofen, and other drugs, smoking, and bacterial infection
 Symptoms include a gnawing pain in the abdomen when stomach
is empty.
 Can be treated with medicines that neutralize or reduce stomach
acids or with antibiotics.
o Colitis
 Inflammation of the Colon
 Could be caused by a virus, an amoeba, a bacterium, or stress
 Symptoms include diarrhea (usually with blood and mucous),
abdominal pain, sometimes fever.
 Medical treatment recommended
o Hemorrhoids
 Swollen veins in the lower rectum and anus
 Result of increased pressure in the veins
 Most common in people who sit a lot, pregnant women after
childbirth, constipated people
 Regular exercise and eating fiber-rich foods can reduce risk of
developing hemorrhoids
o Tooth Decay
 Weakens tooth and affects person’s bite and how they chew food.
 Brush your teeth