Transcript The Digestive System

 Also called the Gastrointestinal System
 Responsible for the physical and chemical breakdown of food.
 System consists of the Alimentary Canal and its accessory organs
 Alimentary Canal-Long tube begins at the mouth and includes: mouth, pharynx,
esophagus, stomach, small intestine, large intestine and anus
 Accessory Organs: Salivary glands, tongue, teeth, liver, gallbladder and pancreas
 AKA Buccal Cavity
 Function to take in food, taste it, physically break it down by teeth, lubricate it and
partially digest it with saliva and swallow
 Teeth physically break food down by chewing and grinding it through a process
called mastication
 The Tongue contains special receptors called taste buds that can taste (sweet, salty,
sour and bitter), also aides in chewing and swallowing food
 The Hard Palate-boney structure that forms the roof of the mouth and separates the
mouth from the nasal cavities
 Soft Palate-Seperates the mouth from the nasopharynx, the Uvula a cone shaped
muscular structure hangs from the middle of the soft palate and prevents food from
entering the nasopharynx during swallowing.
 Salivary Glands
 Three glands: Parotid, Sublingual, and Submandibular
 Saliva lubricates the mouth during speech and chewing and moistens food so that
it can be swallowed easily.
 Contains an enzyme called Salivary Amylase that begins the chemical breakdown
of carbohydrates, or starches into sugars that can be taken into the body.
 Once food has been chewed and mixed with saliva it is called a bolus.
 Tube that carries both air and food
 Air goes to the trachea
 Food goes to the Esophagus
 When food is swallowed muscle action causes the epiglottis to close over the
larynx preventing the bolus from entering the trachea.
 Bolus is force into the esophagus
 Muscular tube dorsal to the trachea
 Receives bolus from pharynx and
delivers it to the stomach
 Relies on rhythmic(wave like)
involuntary muscle contractions
called peristalsis
 Peristalsis moves food in a forward
direction through out the remainder
of the alimentary system
 Enlarged section of the alimentary canal
 Mucus membrane of the stomach contains folds called Rugae that disappear as the
stomach fills with food, allowing for expansion.
 The Cardiac Sphincter- a circular muscle between the esophagus and stomach
closes after food enters keep it from traveling back up the esophagus
 The Pyloric Sphincter-Circular muscle between the stomach and small intestine
keeps food in the stomach until it is ready to enter the small intestine, usually 2-4
hours after it enters
 During that time the bolus is converted into a semifluid material called Chyme, by
gastric juices.
 Gastric Juices are made of; Hydrochloric Acid (kills bacteria, facilitates iron
absorption and activates Pepsin), Lipase (starts chemical breakdown of fats),
Pepsin (chemical break down of proteins)
 Coiled section of the alimentary canal that is approximately 20 feet in length and 1 inch
in diameter.
 Divided into three sections: Duodenum, Jejunum and the Ileum
 Digestion is completed in the small intestine and products are absorbed directly into the
blood stream for use in the body
 Many intestinal juices act on the various nutrients to break them down to usable forms.
These juices originate in accessory organs, gall bladder, pancreas and liver
 The walls of the small intestine are lined with finger like structures called Villi.
 Villi contain capillaries and lacteals which absorb nutrients and either take them to the
liver for direct release into the system or to the thoracic duct where they are stored or
released depending on nutrient and need
 Small intestine empties into Cecum via ileocecal valve which prevents waste from
returning into small intestine
 Final section of the Alimentary Canal
 Five feet in length and 2 inches in diameter
 Absorbs water and any remaining nutrients, primarily stores indigestible materials
before elimination from the body, synthesizes B-vitamins and vitamin k via bacteria
present.
 Divided into series of sections
 Cecum-connects to small intestine, contains appendix
 Colon-Three sections, Ascending, Transverse, Descending (connects to sigmoid colon)
 Sigmoid Colon S shaped section that connects to Rectum
 Rectum final 6-8 inches of intestine which stores waste product
 Anal Canal-Narrow canal that ends the rectum has a hole called the anus in which waste
material leaves the system
 The Liver-Largest gland in the body
 Located upper right quadrant of the body
 Secretes bile which is used to emulsify fats
 Bile makes fats water soluble which is necessary for absorption
 Liver stores sugar as glycogen and releases it into blood stream when needed
 Produces Heparin for clot prevention, blood proteins fibrinogen and prothrombin
that aide in clotting and cholesterol
 Detoxifies the blood contaminated with alcohol, pesticides, or bacteria
 Small muscular sac under the liver
attached by connective tissue
 Stores and concentrates bile
 When need it contracts squeezing
bile out of the cystic duct into the
common bile duct which empties into
the duodenum
 Glandular organ located behind the stomach
 Processes pancreatic juices which contain enzymes that digest food
 Enter the duodenum through the pancreatic duct
 Enzymes include: Pancreatic amylase (breaks down sugar), Trypsin and
chymotrypsin (break down proteins), Lipase and steapsin to (break down fats)
 Produces Insulin, which is secreted into the blood stream, helps with metabolism
and converting glucose into ATP
 Appendicitis
 Acute inflammation of the appendix
 Usually results from obstruction or
infection
 Symptoms include: generalized
abdominal pain, later localized to the
lower right quadrant, nausea and
vomiting, mild fever, elevated white
blood cell count
 If ruptured infection will spill into
peritoneal cavity causing serious
infection called peritonitis
 Treated with appendectomy (removal
of appendix)
 Cirrhosis
 Chronic destruction of liver cells
accompanied by formation of scar
tissue and lose of liver function
 Causes include: hepatitis, bile duct
disease, chemical toxins, malnutrition
associated with alcoholism
 Symptoms; liver enlargement, anemia,
indigestion, nausea, edema in the legs
and feet, hematemesis, nose bleeds,
jaundice, liver failure
 Treatment directed toward preventing
further damage to the liver, Transplant
is an option.
 Constipation
 Fecal matter remains in the colon for
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too long
Causes excessive reabsorption of
water
Matter becomes hard, dry and difficult
to eliminate, which leads to poor bowel
habits, chronic laxative use, “lazy”
bowel
Associated with diet low in fiber and
certain digestive diseases as well as
medication use
Treatment includes; high fiber diet,
adequate fluids and exercise, laxatives
on occasion
 Frequent watery stools
 Caused by; infection, stress, diet,
irritated colon and toxic substances
 Very dangerous in infants and small
children due to excessive fluid loss
 Treatment: eliminate cause, adequate
fluid intake and modifying diet
 Diverticulitis
 Inflammation of the pouches that form
in the intestine as the mucosal lining
pushes through the surrounding
muscle.
 Results in abscess or rupture leading
to peritonitis
 Symptoms include: abdominal pain,
irregular bowel movements, flatus,
constipation or diarrhea, abdominal
distension, low grade fever, nausea
and vomiting
 Treatment; antibiotics, stool softeners,
pain medication, high fiber diet,
Sugery
 Gastroenteritis
 Inflammation of the mucus membrane
that lines the stomach and intestinal
tract
 Causes include; food poisoning,
infection, and toxins
 Symptoms: Abdominal cramping,
nausea, vomiting, fever, diarrhea
 Treatment; rest, increased fluid intake,
antibiotics, intravenous fluids, and
medications to slow peristalsis
 Hemorrhoids
 Painful dilated or varicose veins of the
rectum and or anus
 Caused: straining to defecate,
constipation, pressure during
pregnancy, laxative abuse, insufficient
fluid intake, prolonged sitting of
standing
 Symptoms; pain, itching, and bleeding
 Treatment; high fiber diet, increased
fluid intake, stool softeners, sitz bath,
warm compress, surgical removal
 Hepatitis
 Viral inflammation of the liver
 Type A is highly contagious and is
transmitted through food and water
contaminated through the feces of and
infected person
 Other Types include B, C, D and E
 Symptoms: fever, anorexia, nausea,
vomiting, fatigue, dark colored urine,
clay colored stool, myalgia, enlarged
liver, and jaundice
 Treatment; rest, diet high in protein
and low in fat, transplant if severe
damage
 Hernia
 Internal organ pushes through a
weakened area or natural opening in a
body wall
 Hiatal Hernia is when the stomach
pushes through the diaphragm into the
chest cavity
 Symptoms; heartburn, stomach
distension, chest pain, difficulty
swallowing
 Treatment; bland diet, small frequent
meals, staying upright after eating,
surgical repair
 Inguinal Hernia
 Part of small intestine pushes through
the inguinal rings of the lower
abdominal wall
 Push back through opening
 Surgically reduce if nessecary
 Pancreatitis
 Inflammation of the pancreas due to
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enzymes beginning to digest the
pancreas itself
Can lead to hemorrhage and shock if
the blood vessels are damaged
Causes by alcoholism or blockage due
to gallstones
Symptoms; severe abdominal pain,
nausea, vomiting, diaphoresis, and
jaundice
Treatment; removal of gallbladder,
removal of alcohol and nutrient
intervention if alcoholism is the cause
 Peritonitis
 Inflammation of the peritoneal cavity
usually occurring when intestine
ruptures
 Ruptured appendix or gallbladder
most likely cause
 Symptoms; abdominal pain, distension,
fever, nausea, vomiting
 Treatment; antibiotics, surgical repair
of the intestine
 Ulcer
 Open sore in lining of digestive tract
 Peptic include gastric and duodenal
ulcers
 Major cause is bacteria
 Symptoms; burning pain, indigestion,
hematemesis, melena
 Treatment; antacids, bland diet,
decreased stress, avoidance of
irritants, antibiotics, pepto-bismol,
surgery
 Ulcerative Colitis
 Severe inflammation of the colon
 Accompanied by formation of ulcers
and abscesses
 Caused by stress, food allergy,
autoimmune reaction
 Symptom; diarrhea with blood, pus or
mucus, weigh loss, abdominal pain,
anemia, anorexia
 Treatment; control inflammation,
reduce stress, proper nutrition, avoid
substances that aggravate the
condition, Surgery(Colostomy Bag)