Download The Digestive System

The Digestive System
3 Functions of the Digestive System
1. Digestion -
3 Functions of the Digestive System
1. Digestion – The mechanical
(physical) and chemical breakdown
of foods for use by the body’s cells.
3 Functions of the Digestive System
2. Absorption
3 Functions of the Digestive System
2. Absorption – The passage of
digested food from the digestive tract
into the circulatory system.
Where does most absorption take
place?
3 Functions of the Digestive System
2. Absorption – The passage of
digested food from the digestive tract
into the digestive system.
Where does most absorption take
place?
SMALL INTESTINE
3 Functions of the Digestive System
3. Elimination
3 Functions of the Digestive System
3. Elimination – The expulsion of
undigested food or body wastes.
Ingestion
 The
taking of food into the body
 Eating/Drinking
Structures of the Mouth
 Teeth
– Break the food you eat into smaller
pieces
– Tear, Chomp, & Grind food
Structures of the Mouth
 Tongue
– Forms food into a ball to prepare for
swallowing
– Contains taste buds – allows you to
taste food
Structures of the Mouth
 Salivary
Glands: 3 pair
– Secrete Saliva
– Lubricates food making it easier to
swallow
Saliva
A
watery solution containing an
enzyme (amylase) that starts
breaking down carbohydrates into
simple sugars.
Ooops! Wrong Pipe
 Two
passageways in the back of the
throat. (pharynx)
– Esophagus- food pipe leads to stomach
– Trachea- wind pipe leads to lungs.
Uvula
 Flap
of tissue that covers the nasal
passage so….
Food does not go out the nose
When swallowing.
epiglottis
 Flap
so….
of tissue that covers the trachea
Food does not enter the lungs
Mastication
 The
process of chewing.
Esophagus
 10
inch long muscular tube
connecting the mouth & stomach
 Food take about 9 seconds to travel
through the esophagus
 A sphincter muscle separates the
esophagus from the stomach
1.
Which arrow points
to the esophagus?
3.
2.
5.
4.
6.
Which arrow points
to the esophagus?
1.
1.
3.
2.
5.
4.
6.
Peristalsis
A
series of involuntary muscular
contractions
Digestion
 Starts
in the mouth
 Hollow
The Stomach
saclike organ enclosed in a
muscular wall.
 Continues the breakdown of food
 Stores food– controlling the rate at
which it enters the small intestine
 Mixes food & gastric juices
Gastric Juice
Secretions from the stomach lining that
contain pepsin and hydrochloric acid
 Pepsin is an enzyme that breaks down
protein.
 Hydrochloric acid kills harmful bacteria
taken in with food.

Gastric Juice
 Did
you know…
– Hydrochloric acid in your stomach is
strong enough to dissolve metal.
– If it weren’t for it’s mucus lining, your
stomach would digest itself.
Chyme

A creamy, fluid mixture of food and
gastric juices
 This
The Small Intestine
is where the major part of
digestion & absorption takes place
 20 – 23 feet long
 1 inch in diameter
 3 parts » duodenum, jejunum, ileum
 Lined with millions of villi
Which arrow points
to the Small
Intestine?
1.
3.
2.
4.
5.
6.
Which arrow points
to the Small
Intestine?
4.
1.
3.
2.
4.
5.
6.
The Large Intestine
5
– 6 feet long
 2½
inches in diameter
 Contain
harmless bacteria
The Large Intestine
 Water
is re-absorbed from the waste.
and enters the bloodstream.
 Waste
(feces) collect in the last 4 to
6 inches of the colon known as the
rectum.
Large Intestine (Colon)
 When
the rectum is full nerve
endings are stimulated to eliminate
wastes in a process called
defecation.
 Waste or feces are eliminated
through an opening called the ANUS.
One Long Tube
 The
digestive or Alimentary Canal is
one long tube from the mouth
through the esophagus, into the
stomach through the small intestine
into the large intestine and out the
anus.
Which arrow points
to the Large
Intestine?
1.
3.
2.
4.
5.
Which arrow points
To the rectum?
6.
Which arrow points
to the Large
Intestine?
5.
1.
3.
2.
5
4.
Which arrow points
To the rectum
6.
6.
rectum
Organs that aid in digestion
The Liver



Filters drugs, alcohol &
other poisonous
substances from your
blood.
Stores vitamin A,D,E and
K
Removes worn out red
blood cells.
Liver
 The
largest gland in the body
 Produces
bile- a greenish fluid that
helps “emulsify” fat.
 Your
body’s chemical factory
regulating most of the main
chemicals in the body.
1.
Which arrow points
to the Liver?
3.
2.
4.
5.
6.
1.
Which arrow points
to the Liver?
2.
3.
2
4.
5.
6.
 Liver
Functions
Gallbladder
A
small, pear-shaped sack 3-4 inches
long
 Located underneath the liver
 Stores bile (a yellowish-green, bitter
fluid important in the breakdown of
fats)
1.
3.
2.
4.
5.
6.
Pancreas
 Produces
the hormone insulin
 Produces:
Enzyme
Digests
Trypsin
Proteins
Amylase
Carbohydrates
Lipase
Fats
1.
3.
2.
4.
5.
6.
 Digestive
Process
 Summary
Digestive System
Problems of the Digestive System
 Indigestion
– A burning discomfort in the upper
abdomen
– May be caused by eating too much,
eating too quickly, eating certain foods,
stomach disorders or stress
Problems of the Digestive System
 Heartburn
– A burning pain in the center of the chest
that may travel from the tip of the
sternum to the throat
– Caused by acid reflux – a backflow of
stomach acid into the throat
Problems of the Digestive System
 Gas
– A certain amount of gas in the stomach
or intestine is normal
– Excessive amounts may be caused by
certain foods and may cause discomfort
Problems of the Digestive System
 Nausea
– A feeling of distress, fullness, and
weakness that usually precedes
vomiting
– It can be caused by motion, pathogens,
medicines, drugs or other substances in
the stomach
Problems of the Digestive System
 Diarrhea
– A condition in which the feces are watery and
expelled frequently
– Can be caused by food poisoning, overeating,
stress, nutritional deficiencies, viral and
bacterial infections
Problems of the Digestive System
 Constipation
– A condition in which feces become dry & hard
making bowel movements difficult.
– Caused by medications, lack of fiber, too
little water, lack of exercise, unhealthy eating
Problems of the Digestive System
 Gallstones
– Small crystals that form in the gallbladder
when an upset occurs in the chemical
composition of the bile
– They may block the bile duct causing pain
– Can be treated with medicine, ultrasound –
guided shock waves or surgery
Problems of the Digestive System
 Appendicitis
– The inflammation of the appendix
– Caused by bacteria or other foreign matter
lodging in the appendix
– If the appendix ruptures the infection may
spread to the abdomen which is an extremely
serious condition
1.
3.
2.
4.
5.
6.
Problems of the Digestive System
 Gastritis
– An inflammation of the mucus membrane
that lines the stomach
– Symptoms may include pain, nausea, and
vomiting
– Treated with antibiotics or acid controller
Problems of the Digestive System
 Lactose
Intolerance
– The inability to digest lactose (one of the
sugars present in milk & other dairy
products)
– Caused by and absence of the enzyme
lactase
– Symptoms include severe abdominal cramps,
bloating, gas, & diarrhea.
Problems of the Digestive System
 Peptic
Ulcer
– A sore in the lining of the digestive tract
– Occurs when something damages the
protective lining of the digestive tract &
allows stomach acid to eat away at it
Problems of the Digestive System
 Colitis
– Inflammation of the colon (large intestine)
– Caused by a virus, amoeba, bacterium, or
stress
– Symptoms include diarrhea, abdominal pain,
& sometimes fever
Problems of the Digestive System
 Hemorrhoids
– Swollen veins in the lower rectum and anus
– May be caused by chronic constipation
 Tooth
decay
– Weakens a tooth and affects the way a
person bites & chews
Problems
 Hepatitis
– Inflammation of the liver
– Jaundice- a yellowish coloring of the
skin and mucous membranes