Basic Functions of Abdominal Organs

Most EMT level providers are square on the primary function of the stomach. We can name several things our liver is doing for us and we get the whole kidney concept as well. But when we start drifting beyond the basics, the conversation can turn fuzzy.

OK … It’s been a little while since I studied this. What was the spleen doing again?

Something about the immune system right?

Oh, the Pancreas that produces Insulin doesn’t it?

Or was that the gallbladder?

Fear not. I put together a handy reference for you. Here’s a list of all those abdominal organs for your review. Now you can sort your large intestine from your small and your kidney from you appendix. Let’s get started.

The Liver:

Taking up a large portion of the upper right quadrant, the liver also extends down into the lower right quadrant and across the epigastrium to take up a fair chunk of room in the upper left quadrant as well. When we look at the list of functions for the liver it makes sense why it feels the need to take up some real estate in the upper abdomen. It is the largest gland in the body and there is currently no know way to survive in the complete absence of liver function.

The liver acts as a filter and processing unit for circulating blood. It is a solid organ and very vascular. Complex carbohydrates in the bloodstream are broken down in the liver and stored as glycogen for later use. Proteins and fats are also processed and stored in the liver as alternate energy sources. While it’s busy collecting and storing energy sources – minerals, amino acids and vitamins also get processed, stored and released in the liver.

As part of its filtering duties, the liver plays a primary role in the removal of toxins, poisons, chemicals and drugs from the bloodstream and stores them for later removal by the kidneys. Many of our essential blood clotting factors are also generated here. The liver also plays a minor role in bile production and fat digestion.

Bonus Function– The liver stores a one year supply of vitamin A and always keeps 1-4 months of vitamin D on hand as well.

The Spleen:

The spleen is a solid organ tucked up against the diaphragm in the upper left quadrant nestled between the stomach and the left wing of the liver. It is made of lymphatic tissue and is the largest node in the lymphatic system.

The spleen produces lymph, a fluid necessary for the normal function of the immune system. It also produces B-cells which are critical in the creation of antibody producing plasma cells. It filters and removes bacteria and old cells from the blood. Old cells are recycled as bile and gifted to the liver.

Bonus function– Along with its blood cleaning and immune function responsibilities, the spleen aids the body in blood regeneration in cases of significant blood loss. 30% of your red blood cells and a good supply of platelets are stored in the spleen for just such an emergency.

The Stomach:

Positioned in the mid-epigastrium, the stomach is a J-shaped hollow organ that extends across the left upper quadrant. The stomach can vary dramatically in size depending on the patient and volume of food recently eaten.

Attached to the esophagus, the stomach begins the process of digestion. It receives and stores food. The stomach also excretes enzymes and gastric juices that break down food products and prepare them for the small intestine. Food passes from the stomach to the duodenum, the beginning of the small intestines.

Bonus Function – After a large meal, the stomach can store up to 1.5 liters of food while the small intestine is still working on your appetizer sampler.

The Pancreas: 

Between 4.8 and 6 inches long, the pancreas lies sideways in the lower portion of the upper left quadrant with its head at the midline and its tail resting against the rib cage. The pancreas produces an alkaline juice that is needed in the small intestine to aid digestion. The alkaline pancreatic juice, combined with blie from the gallbladder makes the perfect cocktail to neutralize stomach acids and allow the small intestine to extract nutrients.

When it’s done with its digestive duties, the pancreas also has critical endocrine functions. It manufactures and releases the proper amount of insulin to regulate circulating blood glucose. Insulin is necessary for cells to use sugar for fuel.   

Bonus function– the pancreas produces and releases the hormone glucagon. Glucagon stimulates the liver to release stored glycogen (carbohydrates)

The Kidneys

Well guarded in the retroperitoneal space behind the upper abdominal organs and surrounded by the rib-cage the kidney are solid organs each only slightly larger than a persons ear.

Stored toxins from the liver are passed to the kidneys for elimination. The kidneys regulate body fluids and electrolyte levels. Filtering body fluids, the kidneys withdraw waste such as uria and ammonium and pass it out of the body in urine. Each kidney will pass approximately three cups of urine on to the bladder for elimination each day. This filtering and removal of body fluid also plays a role in blood pressure regulation.

The kidneys are also home to the adrenal glands which produce epinephrine, the primary neurotransmitter of the sympathetic nervous system. 

Bonus function– Your kidneys produce erythropoietin, the substance that cycling athletes can get in hot water over injecting. Erythropoietin is a precursor to red blood cell production.

The Small Intestine:

Beginning at the base of the stomach, the small intestine is a hollow digestive organ that winds its way laterally through the lower left and right quadrants. It is comprised of three sections known as the duodenum, the jejunum and the ileum. Most of the absorption of nutrients from foods takes place in the small intestine.

Large Intestine (Colon):

Beginning in the lower right quadrant, the large intestine extends up (ascending colon) to the umbilicus region, across (transverse colon) to the left peritoneal boarder and down, (descending colon) to the rectum. This is also a hollow organ of digestion, however, the colon primarily withdraws fluid for re-absorption and forms digested food into fecal matter for elimination from the rectum.

Gall Bladder:

Tucked under the liver and attached to the common bile duct, the gall bladder is a hollow organ that stores bile for use in the stomach and duodenum for digestion. Bile plays an essential role in the breakdown of fats in the stomach and small intestine. Approximately 50ml of bile are available in the gal bladder at any given time.

Bonus function – The gal bladder not only stores but also concentrates bile so it is more effective at its job.


Sometimes called a vestigial structure, the appendix has no known useful function. It is theorized to have once played a role in digestion. This theory places the useless structure at the center of some evolution debates.

Bonus function – The appendix may harbor bacteria critical for the normal breakdown of food in the intestinal tract.

With the exception of reproductive organs, that’s a fairly comprehensive fly-by of the organs of the abdomen, their locations and functions. The next time you palpate an abdomen, keep in mind, there’s a lot going on in there.

 Related Articles:

What Is Blood Anyway?

A Guide To Abnormal Behavior

Remembering The Glasgow Coma Score




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