Transcript The Digestive System



A classmate tells you that he missed 3 classes
due to illness. He tells you that he had no
health problems until about 2 months ago
when he started developing recurring bouts
of diarrhea, four times in the past 2 months.
Each time, the diarrhea lasted 3 days and
then went away.
Since you are in an A&P class, he had no
reservations describing that he had semisolid
BM’s with some blood after 2 days of
diarrhea.


During the bouts of diarrhea, he experienced
headaches, mild cramps, and abdominal pain
on the right side, but no fever, nausea, or
vomiting. You notice that your classmate
smokes regularly. He also has significant
stress from school and work. Your classmate
mentions that his mother had an intestinal
disorder, but cannot remember the name of
the disease.
What could be causing your classmate’s
ailments?



Americans eat about 700 million pounds of
peanut butter a year.
Americans eat over 2 billions pounds of
chocolate each year.
In your lifetime, your digestive system may
handle about 50 tons!
30-32
hours
 The
Digestive System is
responsible for the physical
and chemical breakdown of
food so it can be taken into
the bloodstream and used
by body cells and tissues.
A
long, muscular tube that
begins at the mouth and
includes pharynx,
esophagus, stomach, small
intestine, large intestine,
and anus.
The
accessory organs
include salivary
glands, tongue, teeth,
liver, gallbladder, and
pancreas
Receives
the body
Food is:
food as it enters
Tasted
Broken down physically by the teeth
Lubricated and partially digested by
saliva
Swallowed
 Special
structures in the
mouth
 Physically breaks down food
by chewing and grinding the
food, a process called
mastication.
**
 Muscular
organ
 *Contains special receptors
called taste buds that allow a
person to taste sweet, salt,
sour, and bitter sensations
 *Also aids with chewing and
swallowing of food
Bony
structure that
forms the roof of the
mouth
Separates mouth from
nasal cavities
Located behind the hard palate
 Separates mouth from the
nasopharynx
 Uvula

 Cone-shaped muscular structure
 Hangs from the middle of the soft palate
 Prevents food from entering the
nasopharynx during swallowing



Three pairs of glands
Parotid, sublingual, and submandibular
Produce a liquid called saliva
1. Lubricates the mouth during speech and chewing
2. Moistens food so it can be swallowed easily
3. Also contains an enzyme called salivary amylase.
1.
2.
Speeds up a chemical reaction
Begins the chemical breakdown of carbohydrates or
starches into sugars that can be taken into the
body



After food is chewed and mixed with saliva, it
is called a **bolus ** and it enters the
pharynx or throat
The Pharynx carries food from the mouth to
the esophagus.
When bolus is swallowed, muscle action
causes epiglottis to close over larynx
 Prevents bolus from entering respiratory tract

Bolus now enters the esophagus



Muscular tube dorsal to the trachea
Receives bolus from pharynx and
carries it to the stomach
Relies on a rhythmic, wavelike
involuntary movement of its muscles,
called **peristalsis** to move the food
in a forward direction
 The
enlarged part of
alimentary canal
 Receives food from esophagus
 Mucous membrane lining
contains folds called rugae.
They disappear as stomach
fills with food and expands.

**Gastric Juices**
◦ Produced by glands in the stomach
◦ Converts food into a semi-fluid material called
chyme.
◦ Juices contain hydrochloric acid
 Kills bacteria
 Facilitates absorption of iron
◦ Juices also contain enzymes
 Lipase-begins chemical breakdown of fats
 Pepsin-starts protein digestion
 Rennin-only present in infants, aids in digestion of milk
 The
Cardiac Sphincter
Circular muscle between
esophagus and stomach
Closes after food enters
stomach
Prevents food from going
back up into the esophagus
 The
Pyloric Sphincter
 Circular muscle between
stomach and small intestine
 Keeps food in stomach until it
is ready to enter small
intestine
 *Food usually remains in the stomach for about two to
four hours
Cardiac
Sphincter
Pyloric Sphincter
1.
Completes the process of
digestion
2. Absorbs products of digestion
into bloodstream for use by
body cells
 The
Small Intestine is a coiled
section of the alimentary canal
about 20 feet long and 1 inch
in diameter.
 Receives food, in form of
chyme, from the stomach.
 There are three sections of the
small intestine.
 The
first 9-10 inches of the
small intestine.
 Bile from the gallbladder and
liver and pancreatic juice from
pancreas enter this section
through ducts or tubes.
 Liquid
that enters small intestine
from liver and gallbladder
 Emulsifies,
down fats
or physically breaks
 Liquid
that enters small intestine
from pancreas
 Contains
enzymes that complete
the process of digestion
About
Forms
8 feet long
the middle
section of small
intestine
 Final
12 feet
 Connects with large intestine at
the cecum
 Circular muscle called ileocecal
valve separates ileum and cecum
and prevents food from returning
to ileum.
Produced by small intestine
 Contains the enzymes maltase, sucrease, and
lactase, which break down sugars into
simpler forms
 Contain enzymes known as peptidases, which
complete digestion of proteins
 Contain the enzyme steapsin (lipase) which
aids in digestion of fat.
*In your workbook pages*




Fingerlike projections that line the wall of
small intestine that contain blood capillaries
Allow food to be absorbed or taken into
bloodstream
Blood capillaries absorb digested nutrients
and carry them to the liver where they are
stored or released into general circulation for
use by body cells
If you flattened out all
the villi of the small
intestine…..it would
cover an entire tennis
court!
 Final
canal
section of the alimentary
 About
5 feet long and 2 inches
in diameter



Absorption of water and any remaining
nutrients
Storage of indigestible materials before they
are eliminated from the body
Transportation of the waste products out of
the alimentary canal
 Cecum
 Colon
 Rectum

First section

Connects with ileum of small intestine

Contains a small projection called the
vermiform appendix





Four divisions:
Ascending colon continues up on the right side
of the body from cecum to lower part of liver.
Transverse colon extends across the abdomen,
below liver and stomach, but above the small
intestine
Descending colon extends down left side of body
Sigmoid colon
 Connects with descending colon
 S-shaped section that joins with rectum
Final 6-8 inches
 Storage area for the indigestible
material, or wastes
 Has a narrow canal called the anal
canal, which opens at a hole called the
anus
 Fecal material, or stool, the final waste
product of the digestive process, is
expelled through this opening




The liver is the largest gland in the
body
It is an accessory organ for the
digestive tract
Located under the diaphragm in right
upper quadrant of abdomen. (RUQ)
1.
Secretes bile
a)
b)
2.
Stores sugar in the form of glycogen
a)
b)
3.
4.
Used to emulsify, or physically break up fats
Also makes fats water soluble, which is necessary for
absorption
Glycogen is converted to glucose
Released into bloodstream when additional blood sugar
is needed
Stores iron and certain vitamins
Produces blood proteins such as fibrinogen
and prothrombin, which aid in clotting of
blood
5. Produces cholesterol
6. Detoxifies (renders less harmful) substances
such as alcohol and pesticides and destroys
bacteria that have been taken into the blood
from the intestine

Small, muscular sac

Located under the liver and attached to it by
connective tissue

Stores and concentrates bile, which it receives
from the liver

When bile is needed in the digestive tract to
emulsify fats, the gallbladder contracts and
pushes the bile through the cystic duct into
the common bile duct, which drains into the
duodenum.



Fish-shaped organ located behind the
stomach
Produces pancreatic juices
 Juices enter duodenum through
pancreatic duct
 Contain enzymes to digest food
Produces insulin
 Secreted into the bloodstream
 Regulates metabolism, or burning of
carbohydrates to convert glucose (blood
sugar) to energy
Acute inflammation of the
appendix usually caused by
an obstruction and/or
infection
1.
Generalized abdominal pain that later
localizes at the lower right quadrant (RLQ)
2.
Nausea and vomiting
3.
Mild fever
Elevated white blood cell count
**Rebound tenderness**
4.



Appendectomy
Antibiotics
**If appendix ruptures, infectious material
spills out into peritoneal cavity and causes
peritonitis, a serious condition**
Inflammation of the
gallbladder
 Frequently
the inflammation
is caused by Cholelithiasis
or gallstones. They form
from crystallized
cholesterol, bile salts, and
bile pigments.

Symptoms frequently occur after eating fatty
foods
 Indigestion, nausea, and vomiting
 Pain under rib that radiates to right
shoulder
 If gallstone blocks bile ducts,
gallbladder can rupture and cause
peritonitis



Low-fat diets
Lithotripsy: shock waves to shatter
gallstones
Cholecystectomy: surgical removal of
gallbladder
Chronic destruction of
liver cells accompanied by
formation of fibrous
connective and scar tissue
 Malnutriiton
 Alcoholism
 Hepatitis
 Bile
duct disease
 Chemical toxins

Symptoms vary and become more severe as
disease progresses:
Enlargement of the liver
Anemia and nosebleeds
Indigestion, nausea, and vomiting
Edema in legs and feet
Hematemesis, or vomiting blood
Jaundice or yellow discoloration
Ascites, or an accumulation of fluid in abdominal
peritoneal cavity
 When liver function fails, disorientation, hallucinations,
hepatic coma, and death occur







Ascities:

Treatment is directed toward preventing
further damage to the liver





Avoiding alcohol and preventing infections
Proper nutrition and vitamin supplements
Diuretics to reduce ascites and edema
Rest and appropriate exercise are encouraged
Liver transplant may be performed in too much
of the liver is destroyed
Condition that occurs
when fecal material
remains in the colon too
long, causing excessive
re-absorption of water


Poor bowel habits
Chronic use of laxatives causing a “lazy”
bowel

Diets low in fiber

Certain digestive diseases
 Usually
corrected by a diet high in
fiber, adequate fluids, and
exercise
 At times, laxatives are used to stimulate
defecation
Condition characterized
by frequent watery
stools

Infections

Diet

Irritated colon

Toxic substances

Eliminate the cause

Provide adequate fluid intake

Modify the diet

**Extremely dangerous in infants and small
children due to the excessive loss of
fluids**
Inflammation of diverticulum, pouches or
sacs that form in the intestine as the
mucosal lining pushes through the
surrounding muscles


When fecal material
and bacteria
become trapped in
diverticulum,
inflammation
occurs
Can cause an
abscess or rupture,
leading to
peritonitis

Symptoms vary depending on the amount of
inflammation
 Abdominal pain
 Irregular bowel movements and flatus
(gas)
 Constipation or diarrhea
 Abdominal distention (swelling)
 Low-grade fever
 Nausea and vomiting

Antibiotic

Stool softening

Pain medications

High-fiber diet

Surgery to remove the affected section of the
colon
http://www.youtube.com/watch?v=Q1
27uOBRtok&feature=related
Irritable Bowel
Syndrome (IBS)
A functional bowel disorder characterized by
chronic abdominal symptoms
Nervous
Colon
Mucous Colitis
Spastic Bowel
 Abdominal
pain
 Bloating
 Constipation
 Diarrhea
 Occasional
bleeding
 Nutritional
counseling
 Psychological counseling
(stress)
 Analgesics
 Anti-inflammatory
medications
Inflammation of mucous
membrane lining of the
stomach and intestinal
tract
 Food
poisoning
 Infections
 Toxins

Abdominal cramping

Nausea

Vomiting

Fever

Diarrhea


Usually rest and increased fluid intake
In severe cases, antibiotics, intravenous
fluids, and medications to slow peristalsis
may be used.
Painful, dilated (or
varicose) veins of the
rectum and/or anus
1.
2.
3.
4.
5.
Straining to defecate or
constipation
Pressure during pregnancy
Insufficient fluid intake
Abuse of laxatives
Prolonged sitting or standing
 Pain
 Itching
 Bleeding

High-fiber diet and increased fluid intake

Stool softeners

Sitz baths or warm, moist compresses

Hemorrhoidectomy in severe cases
http://www.youtube.com/watch?v=CJY
mqyHGl-I&NR=1&feature=fvwp
Viral inflammation
of the liver
 Type
A (HAV) or infectious
Hepatitis
◦ Highly contagious
◦ Transmitted in food or water that has
been contaminated by the feces of an
infected person
◦ Most benign form of hepatitis and is
usually self-limiting
◦ Vaccine is available to prevent Hepatitis A

Type B (HBV), or serum Hepatitis
◦ Transmitted by body fluids including
blood, serum, saliva, urine, semen, vaginal
secretions, and breast milk
◦ More serious than type A and can lead to
chronic hepatitis or cirrhosis of the liver
◦ Hepatitis B vaccine recommended for all
healthcare workers
 Type
C, or HCV
◦ Also spread through contact with blood or
body fluids
◦ Main methods of transmission include
sharing needles while injecting drugs,
getting stuck with a contaminated needle
or sharp object on the job, or passing the
virus from an infected mother to the infant
during birth
◦ More likely to progress to chronic
hepatitis and/or cirrhosis.
◦ No vaccine for Hepatitis C



Rest
Diet high in protein and calories and low in
fat
Liver transplant may be necessary if liver is
severely damaged
Occurs when an internal
organ pushes through a
weakened area or
natural opening in a
body wall

Stomach protrudes through diaphragm into
chest cavity through opening for esophagus

Symptoms: heartburn, distention of the

Treatment: bland diet; small, frequent meals;
stomach, chest pain, and difficulty swallowing
not lying down after eating; and surgical
repair.


Section of small intestine protrudes through
inguinal rings of the lower abdominal wall
If the hernia cannot be reduced, or pushed
back in place, surgical repair is done.
Umbilical Hernia
Inflammation of the pancreas
in which pancreatic enzymes
begin to digest the pancreas
 The
pancreas becomes necrotic,
inflamed, and edematous
(swelling)
 When
damage extends to blood
vessels in the pancreas,
hemorrhage and shock occur



Excessive alcohol consumption
Blockage of pancreatic ducts by
gallstones
Many cases are idiopathic, or of
unknown cause





Severe abdominal pain that radiates to the
back
Nausea
Vomiting
Diaphoresis (excessive perspiration)
Jaundice if swelling blocks the common bile
duct

Treatment depends on the cause
◦ Cholecystectomy if gallstones are the cause
◦ Analgesics for pain
◦ Nutritional support if the cause is alcoholism.
(Pancreatitis caused by alcoholism has a poor
prognosis)
Inflammation of
the abdominal
peritoneal cavity
Usually occurs when a rupture in the
intestine allows fecal contents to enter
this cavity


Ruptured appendix or gallbladder are
some causes.
 Abdominal
pain
 Abdominal distention
 Fever
 Nausea
 Vomiting
 Antibiotics
 Surgical
repair
Open sore on
the lining of the
digestive tract
 Major
cause is Heliobacter
pylori (H. pylori)
 Bacterium that burrows into
stomach membranes
 Allows stomach acids and
digestive juices to create an
ulcer
 Burning
pain
 Indigestion
 Hematemesis (bloody
vomitus)
 Melena (dark, tarry stool)
1.
2.
3.
4.
5.
6.
Antacids and bland diet
Decreasing stress
Avoid irritants such as alcohol, fried food,
tobacco, and caffeine
If H. pylori bacteria are present, treatment
with antibiotics are usually recommended.
In severe cases, surgery to remove the
affected area
Antibiotics to kill bacteria that can cause
ulcers
Severe
inflammation of the
colon with the
formation of ulcers
and abscesses
Ulcers
Polyps
Stress
!?!?!?
Allergic reactions to
food
Autoimmune reaction


Main symptom DIARRHEA, including blood,
pus, and mucus
Others:
 Weakness
 Weight loss
 Abdominal pain
 Anemia
 Anorexia
Ulcerative
Colitis has
periods of remission
and exacerbation
***Control inflammation***
 Reduce stress
 Maintain proper nutrition
 Avoid substances that aggravate condition
 In some cases, surgical removal of an
affected colon.
(Possible colostomy)