Abdominal Cavity | Definition, Organs, and Functions
Abdominal Cavity Definition
What is the abdominal cavity: The cavity of the abdomen is called the abdominal cavity. It is a space in the body where many organs are located, including the stomach, small intestines, large intestines, liver, spleen, and kidneys.
It has a closed top and open bottom that allow for passaging materials out of or into it. The diaphragm forms its upper boundary, while the pelvic floor forms its lower boundary. It contains 3 layers; the innermost lining is the peritoneum (folds) which covers most of the abdominal organs inside to prevent friction between them and keeps them in place; next, there’s fat tissue forming an adipose layer (which stores energy); at lastly is a (connective tissue).
Abdominal Cavity Anatomy:
Abdominal Cavity Organs:
Organs of the abdominal cavity are described below:
The stomach is a muscular, simple sack-shaped organ in the upper abdomen. It receives food from the esophagus through a muscular valve called the esophageal sphincter and passes small portions of partially digested food into it for digestion.
Functions of Stomach
The stomach has three mechanical tasks. The first is to increase and decrease the pressure inside the abdominal cavity (through contractions). This helps mix up food with digestive juices.
Second, it prepares food for further processing by grinding it up with enzymes.
Third, store indigestible until it can pass out of the body through feces.
The liver is one of our biggest organs and acts as an industrial complex. It turns nutrients and toxins into usable substances.
Functions of Liver
The liver has two functions:
- Help in the synthesis of proteins, lipids, blood clotting factors, and other products.
- Also, aids in the detoxification of harmful substances by the secretion of bile.
3. Gall bladder
The gall bladder is a small sac-shaped organ that lies under the liver. The gall bladder stores bile produced by the liver and assists in the digestion of fatty foods. The gall bladder can store two to three ounces of bile.
The spleen is mostly a blood filtration organ. It filters red blood cells and helps the body’s immune system fight off infections and other foreign invaders.
The pancreas is behind the stomach in an area called the epigastric region. The pancreas makes enzymes that aid in cell digestion or break down large food molecules into smaller ones so they can absorb them through the small intestine walls, as well as hormones including insulin, glucagon, somatostatin, and pancreatic polypeptide.
6. Small Intestines
The small intestine is the central part of the digestive tract in animals, which mainly absorbs nutrients from food. The small intestine is composed of three parts: duodenum, Jejunum, and Ileum. The duodenum is a short segment that begins at the pyloric sphincter of the stomach and leads into the jejunum and then to the thin, tubular section called the ileum.
The small intestine has three major functions:
The first is to break down food molecules into particles small enough to be absorbed through the intestinal wall.
Second, it absorbs nutrients into the body, including proteins, carbohydrates, fats, vitamins, and minerals.
Third, it helps pass non-absorbed materials out of the body as feces.
Small Intestine Parts & Functions:
Duodenum – breaks food down further for absorption; secretes hormones that help control stomach acid secretion via bile released by the gallbladder and pancreatic juices via enzymes produced in the pancreas
Jejunum – begins at pyloric sphincter of the stomach leading up to Ileum
Ileum – leads to the large intestine
7. Large intestine
The large intestine, also called the colon, is the last part of the digestive system, which absorbs water from indigestible residue and prepares for defecation. Excretion of feces occurs here. It is composed of three parts: the cecum, colon, and rectum. The large intestine has three main functions:
First, it absorbs water back into the body.
Second; it helps in making solid wastes more compact by removing more fluid from them.
Third, deposits of feces are a waste product that goes out through defecation.
Large Intestine Parts & Functions:
Cecum – the first part of the large intestine where the appendix is attached
Colon – stores fecal matter temporarily before emptying into the rectum
The kidneys are two bean-shaped organs that sit on either side of the spine in the back and just below the rib cage. The kidneys filter out wastes and extra fluid from the blood, which passes from the body through urine.
Kidneys also produce hormones such as erythropoietin, which controls bone marrow production of red blood cells. They maintain proper levels of electrolytes (salts) in the bloodstream by adjusting excretion to keep a steady concentration of ions.
The bladder is a hollow organ inside your pelvis. It stores urine until it’s full, then forces it out of your body through your urethra when you urinate.
Abdominal Cavity Vessels
1. Abdominal Aorta and Vena Cava
The abdominal aorta is the major artery that supplies blood to the lower half of the body and the legs. It branches into arteries that send blood to each part of your lower body.
The vena cava is a large vein that carries blood from throughout the body back up to your heart. The liver, pancreas, and spleen receive a dual blood supply from both the aorta and vena cava, which helps meet their high metabolic demands for oxygen and nutrients.
2. Celiac trunk
The celiac trunk is a short artery on the left side of the upper abdomen near where it meets the stomach. It branches off to form major arteries supplying blood flow to your stomach, spleen, liver, gallbladder, superior part of the duodenum. It is formed by the anterior division of the abdominal aorta.
3. Superior Mesenteric Artery
The superior mesenteric artery (or SMA) is located on the front of your abdomen, below your diaphragm. Its branches run up and down both sides of your small intestine to supply it with blood.
4. Inferior pancreatic artery
The inferior pancreatic artery is one of three main arteries that branch off from the celiac trunk to provide blood flow to the pancreas. The other two are called anterior and posterior superior pancreaticoduodenal arteries.