3rd Entry

The Stomach

The stomach lies between the Esophagus(which was explained in the 2nd Entry)and the duodenum(The first part of the small intestines).


Well,lets have a little recap...

Scene 1:Your mouth makes mincemeat out of some apple pie you decided to eat.Yum Yum.

Scene 2:You swallow the apple pie,and it passes through the Esophagus(OR Oesophagus.They are both the same thing) by Peristalsis.

Scene 3: ...........

The stomach generates strong acids and enzymes to help in digestion(This mixture of acids and enzymes is called gastric juice),and the inner lining of it has several mechanisms to resist the effect of gastric juice on itself, but the esophagus does not.

This means that the gastric juice from the stomach can always go up into the Esophagus and we would have a very serious gullet problem in our hands daily.

Thanks to the Lower Esophageal Sphincter(Cardia,or just Esophagus Sphincter),it helps prevent that from happening(:o you won't stare at those Super Mario games and wished you could jump like that,thank gosh).Of course,for some people who tend to eat supper daily,when they are old due to the digestive system used to eating extra food,the stomach creates more gastric acid.And that results in heartburn.

Owch.

The esophagus is protected from these acids by a one-way valve mechanism at its junction with the stomach. This one-way valve is called the esophageal sphincter (as introduced above), and prevents gastric juice from flowing back into the esophagus.

Or your apple bits from going up the esophagus.

Or last night's chicken scraps.

Whatever.

So your apple bits pass through the esophagus,go right past the esophageal sphincter,and into the stomach,with no way to go back.Looks like it's 'Game Over' for our apple bits.

In humans, the stomach has a relaxed, empty volume of about 45 ml. It generally expands to hold about 1 litre of food, but can hold as much as 1.5 liters.

The stomach is like a bag of muscles,with gastric juice inside to aid the digestion.

The stomach is lined with mucus to protect it from the stomach acid,so you don't get digested by your own stomach.Of course,that is possible,but only occurs when you do not eat regularly or for a long period of time.

Now in order to prevent the 'Once-was-your-happy-apple-pie' stuff to just pass through the stomach and into the duodenum(and then into the small intestines),the stomach's acids need time to actually dissolve the apple bits.Just a 10 second whoosh through the stomach like you're in a theme park would not do much help.

When the food is still in the stomach,the Protease enzymes are secreted into the stomach and and digest the proteins.

Thus,the Pyloric sphincter (or Pylorus) is there,working with the Esophageal sphincter,to 'lock up' the stomach for a good few hours so that the food would be rather dissolved.

Pylorus,in greek,is 'Gate guard'.Now we know where that name came from.

The pylorus is connected to the duodenum,and is divided into 2 parts:

The pyloric antrum, which connects to the body of the stomach.
The pyloric canal, which connects to the duodenum.

The pyloric sphincter, or valve, is a strong ring of smooth muscle at the end of the pyloric canal and lets food pass from the stomach to the duodenum.

Bored to TEARS with this boring chunk of english text?Lets watch a video!




Woah!Lets take a break from the stomach adventure and to something new.

The Gallbladder

This buddy stores about 50 mL of bile(created by the liver),which is released when food containing fat enters the digestive tract(The digestive system).

After being stored in the gallbladder, the bile becomes more concentrated than when it left the liver, increasing its potency and intensifying its effect on fats.

Most digestion occurs in the heat.

The human gallbladder is shaped like a pear, although the organ's shape and function vary considerably among other mammalian species.





Links:
http://en.wikipedia.org/wiki/Stomach
http://en.wikipedia.org/wiki/Cardia#Function
http://www.healthline.com/blogs/exercise_fitness/uploaded_images/VikkiHamTreeStretch-708771.jpg
http://en.wikipedia.org/wiki/Pylorus
http://en.wikipedia.org/wiki/Duodenum
http://en.wikipedia.org/wiki/Gallbladder
http://www.youtube.com/watch?v=qTEun6mHmzA&eurl=http%3A%2F%2Fbiochembloggie.blogspot.com%2F&feature=player_embedded