PHysilogy system
The digestive system is made up of the digestive tract—a series of hollow
organs joined in a long, twisting tube from the mouth to the anus—and other
organs that help the body break down and absorb food (see figure).
Organs that make up the digestive tract are the mouth, esophagus, stomach,
small intestine, large intestine—also called the colon—rectum, and anus. Inside
these hollow organs is a lining called the mucosa. In the mouth, stomach, and
small intestine, the mucosa contains tiny glands that produce juices to help
digest food. The digestive tract also contains a layer of smooth muscle that
helps break down food and move it along the tract.
Two “solid” digestive organs, the liver and the pancreas, produce digestive
juices that reach the intestine through small tubes called ducts. The
gallbladder stores the liver's digestive juices until they are needed in the
intestine. Parts of the nervous and circulatory systems also play major roles in
the digestive system.
-The main parts in the process of the Digestive
system will be highlighted.
PROCESS OF DIGESTIVE SYSTEM
A. Types of Digestion
1. Mechanical digestion is the actual physical break down of food into smaller
pieces. One example of this is mastication (chewing) which occurs in the mouth
by the teeth, which act to cut and grind food into smaller pieces. This makes
them easier to later digest as it increases the SA of the food molecules. A
certain type of food is made of lots of different chemicals but certain
chemicals are found in the center. The chewing breaks it apart and exposes these
chemicals so that they can be broken down quicker/easier.
2.Chemical digestion on the other hand, is the chemical break down of foods into
smaller pieces. An example of this is how enzymes break them down. In
particular, the enzyme salivary amylase is found in our saliva which acts to
break down starch into simpler forms (polysaccharides --> dissaccharides).
Another form of this digestion is how the HCl acid in the stomach helps to break
down food and destroy any microorganisms that accompanied the food
B. Parts of the System
Digestion in the Mouth
Teeth- Digestion starts here. The job of the teeth is to
start tearing and crushing the food down into small enough pieces so that it can
fit down our throats.
Saliva- The salivary gland in located underneath the back of
our tongue. It creates our saliva or spit. This helps soften the food in the
mouth so that it is easier to swallow. Saliva is also the first of several
chemicals that start to break down foods into simpler forms.
Tongue- The tongue is a muscle that works with the food and
saliva to form a "ball" that can be swallowed. Of course, the tongue also
contains taste buds that helps us tell the difference between salty, sour,
sweet, and bitter foods.
Esophagus- The esophagus is simply a transportation tube
from the mouth to the stomach. When we swallow, what we are really doing is
closing a trap door in our throat called the epiglottis. This sends food down
the esophagus and prevents food from going down the trachea (or windpipe) and
into our lungs. Food moves down the esophagus using muscles not gravity.
organs joined in a long, twisting tube from the mouth to the anus—and other
organs that help the body break down and absorb food (see figure).
Organs that make up the digestive tract are the mouth, esophagus, stomach,
small intestine, large intestine—also called the colon—rectum, and anus. Inside
these hollow organs is a lining called the mucosa. In the mouth, stomach, and
small intestine, the mucosa contains tiny glands that produce juices to help
digest food. The digestive tract also contains a layer of smooth muscle that
helps break down food and move it along the tract.
Two “solid” digestive organs, the liver and the pancreas, produce digestive
juices that reach the intestine through small tubes called ducts. The
gallbladder stores the liver's digestive juices until they are needed in the
intestine. Parts of the nervous and circulatory systems also play major roles in
the digestive system.
-The main parts in the process of the Digestive
system will be highlighted.
PROCESS OF DIGESTIVE SYSTEM
A. Types of Digestion
1. Mechanical digestion is the actual physical break down of food into smaller
pieces. One example of this is mastication (chewing) which occurs in the mouth
by the teeth, which act to cut and grind food into smaller pieces. This makes
them easier to later digest as it increases the SA of the food molecules. A
certain type of food is made of lots of different chemicals but certain
chemicals are found in the center. The chewing breaks it apart and exposes these
chemicals so that they can be broken down quicker/easier.
2.Chemical digestion on the other hand, is the chemical break down of foods into
smaller pieces. An example of this is how enzymes break them down. In
particular, the enzyme salivary amylase is found in our saliva which acts to
break down starch into simpler forms (polysaccharides --> dissaccharides).
Another form of this digestion is how the HCl acid in the stomach helps to break
down food and destroy any microorganisms that accompanied the food
B. Parts of the System
Digestion in the Mouth
Teeth- Digestion starts here. The job of the teeth is to
start tearing and crushing the food down into small enough pieces so that it can
fit down our throats.
Saliva- The salivary gland in located underneath the back of
our tongue. It creates our saliva or spit. This helps soften the food in the
mouth so that it is easier to swallow. Saliva is also the first of several
chemicals that start to break down foods into simpler forms.
Tongue- The tongue is a muscle that works with the food and
saliva to form a "ball" that can be swallowed. Of course, the tongue also
contains taste buds that helps us tell the difference between salty, sour,
sweet, and bitter foods.
Esophagus- The esophagus is simply a transportation tube
from the mouth to the stomach. When we swallow, what we are really doing is
closing a trap door in our throat called the epiglottis. This sends food down
the esophagus and prevents food from going down the trachea (or windpipe) and
into our lungs. Food moves down the esophagus using muscles not gravity.
Stomach
The first stop after the esophagus is the stomach.
Once the food gets to the stomach the stomach uses chemicals to try to make
the food tinier. These chemicals are called gastric juices and the include
hydrochloric acid and enzymes (chemicals that break down food). The food is
moved around in the stomach and mixed with the chemicals for about 3 or 4 hours.
When it is done in the stomach, the food is now a cream-like liquid
call chyme. The food is still not small enough the get into our blood
stream and it has not provided the body with anything useful yet. Now a
valve at the end of the stomach opens sending the food past the
liver.
Liver/Gall Bladder
At this point, our food is hit with more chemicals.
The liver makes a chemical called bile but bile is not
stored in the liver. Instead it is stored in the gall bladder. When the
gall bladder mixes bile with our food, it does an important job: breaking
down the fat (from milk, butter, cheeses) into tiny droplets. This fat will
supply us with much energy later.
Pancreas
The pancreas also adds a digestive chemical as the
food leaves the stomach. This digestive juice works on breaking down the
carbohydrates (from breads, potatoes, etc.) and the proteins (from meats,
cereals, peanut
butter).
Small Intestine
The small intestine is the real hero of the
digestive system. The small intestine is a tube that is about
22 feet long! This is where the real digestion takes place. As the food
passes through, it is mixed with the new chemicals and soon our "food" is
now digested small enough to be put to use by the body. Along the walls of
the intestine are thousands of tiny fingers called villi. Blood vessels
(capillaries) in the villi can absorb the tiny food molecules and send them
off to the rest of our body through the
blood.
Large Intestine
Whatever the body cannot put to use is sent to the large intestine.
Many plants, for example, contain cellulose which cannot be digested
The big job of the large intestine is to remove water. Water has
been necessary up until now but it is no longer needed and in the large
intestine water is sent into the blood stream . Food spends about 12 hours
in the large intestine where it become feces and later leaves the body
through the anal opening when we go to the bathroom
Colon
Is the last part of the digestive system in most vertebrates.It extracts water and salt from solid waste before they are eliminated from the body and is the site in which
flora-aided (largely bacterial) fermentation of
unabsorbed material occurs. Unlike the small intestine, the colon does not play a major
role in absorption of foods and nutrients. However, the colon does absorb water,
sodium and some fat soluble vitamins.
Rectum
The rectum is a chamber that begins at the end of the large intestine,
immediately following the sigmoid colon, and ends at the anus. Ordinarily, the
rectum is empty because stool is stored higher in the descending colon.
Eventually, the descending colon becomes full, and stool passes into the
rectum, causing an urge to move the bowels.
c.Condtions of the digestive system
1. Peptic Uclers- In the digestive system, an ulcer is an area where tissue has been destroyed
by gastric juices and stomach acid. Peptic ulcer disease is a general term for
ulcers that occur in the stomach or duodenum (upper part of thesmall
intestine). In the digestive system, an ulcer is an area where tissue has been destroyed
by gastric juices and stomach acid. Peptic ulcer disease is a general term for
ulcers that occur in the stomach or duodenum (upper part of the small
intestine). A peptic ulcer is an erosion or sore in the wall of the gastrointestinal tract.
2. Heart Burn- Despite its name, heartburn has nothing to do with the heart. Some of the
symptoms, however, are similar to those of a heart attack or heart disease.Heartburn is an irritation of the
esophagus that is caused by stomach acid. This can create a burning discomfort
in the upper abdomen or below the breast bone.
Understanding Heartburn
With gravity's help, a muscular valve called the lower esophageal sphincter,
or LES, keeps stomach acid in the stomach. The LES is located where the
esophagus meets the stomach -- below the rib cage and slightly left of center.
Normally it opens to allow food into the stomach or to permit belching; then it
closes again. But if the LES opens too often or does not close tight enough,
stomach acid can reflux, or seep, into the esophagus and cause the burning
sensation.Occasional heartburn isn't dangerous, but chronic heartburn or
gastroesophageal reflux disease (GERD) can sometimes lead to serious problems.
Heartburn is a weekly occurrence for about 20% of Americans and very common in
pregnant women.
What Causes Heartburn?
The basic cause of heartburn is a lower esophageal sphincter, or LES, that
doesn't tighten as it should. Two excesses often contribute to this problem: too
much food in the stomach (overeating) or too much pressure on the stomach
(frequently from obesity or pregnancy). Certain foods commonly relax the LES,
including tomatoes, citrus fruits, garlic, onions, chocolate, coffee, alcohol,
caffeinated products, and peppermint. Dishes high in fats and oils (animal or
vegetable) often lead to heartburn, as do certain medications. Stress and lack
of sleep can increase acid production and can cause heartburn. And smoking,
which relaxes the LES and stimulates stomach acid, is a major contributor.
Digestion of Sugars
Simple carbohydrates, or sugars,
are digested by an enzyme in the lining of the small intestine
Digestion of Proteins
Most proteins are decomposed to single amino acids in digestion.
Digestion typically begins in the stomach when pepsinogen is converted
to pepsin by the action of hydrochloric acid, and continued by trypsin
in the small intestine.
Digestion of Fat
Fat taken in the diet is digested in the Small Intestine with the aid of Bile acids and
salts which act as emulsifiers and break down the larger fat droplets into
smaller ones. These are then acted upon by "lipases" which are secreted in the
intestinal digestive.
by gastric juices and stomach acid. Peptic ulcer disease is a general term for
ulcers that occur in the stomach or duodenum (upper part of thesmall
intestine). In the digestive system, an ulcer is an area where tissue has been destroyed
by gastric juices and stomach acid. Peptic ulcer disease is a general term for
ulcers that occur in the stomach or duodenum (upper part of the small
intestine). A peptic ulcer is an erosion or sore in the wall of the gastrointestinal tract.
2. Heart Burn- Despite its name, heartburn has nothing to do with the heart. Some of the
symptoms, however, are similar to those of a heart attack or heart disease.Heartburn is an irritation of the
esophagus that is caused by stomach acid. This can create a burning discomfort
in the upper abdomen or below the breast bone.
Understanding Heartburn
With gravity's help, a muscular valve called the lower esophageal sphincter,
or LES, keeps stomach acid in the stomach. The LES is located where the
esophagus meets the stomach -- below the rib cage and slightly left of center.
Normally it opens to allow food into the stomach or to permit belching; then it
closes again. But if the LES opens too often or does not close tight enough,
stomach acid can reflux, or seep, into the esophagus and cause the burning
sensation.Occasional heartburn isn't dangerous, but chronic heartburn or
gastroesophageal reflux disease (GERD) can sometimes lead to serious problems.
Heartburn is a weekly occurrence for about 20% of Americans and very common in
pregnant women.
What Causes Heartburn?
The basic cause of heartburn is a lower esophageal sphincter, or LES, that
doesn't tighten as it should. Two excesses often contribute to this problem: too
much food in the stomach (overeating) or too much pressure on the stomach
(frequently from obesity or pregnancy). Certain foods commonly relax the LES,
including tomatoes, citrus fruits, garlic, onions, chocolate, coffee, alcohol,
caffeinated products, and peppermint. Dishes high in fats and oils (animal or
vegetable) often lead to heartburn, as do certain medications. Stress and lack
of sleep can increase acid production and can cause heartburn. And smoking,
which relaxes the LES and stimulates stomach acid, is a major contributor.
Digestion of Sugars
Simple carbohydrates, or sugars,
are digested by an enzyme in the lining of the small intestine
Digestion of Proteins
Most proteins are decomposed to single amino acids in digestion.
Digestion typically begins in the stomach when pepsinogen is converted
to pepsin by the action of hydrochloric acid, and continued by trypsin
in the small intestine.
Digestion of Fat
Fat taken in the diet is digested in the Small Intestine with the aid of Bile acids and
salts which act as emulsifiers and break down the larger fat droplets into
smaller ones. These are then acted upon by "lipases" which are secreted in the
intestinal digestive.
Process Of Digestive SySTem VIDEO
Please Click on the link below for a video which informs you about you about the
steps in the Digestive System.
http://www.neok12.com/php/watch.php?v=zX680f4e7e6e7c420f746402&t=Digestive-System
steps in the Digestive System.
http://www.neok12.com/php/watch.php?v=zX680f4e7e6e7c420f746402&t=Digestive-System