Department of Biology, Mekelle University, Mekele, Ethiopia
Received: 24 -Mar-2022, Manuscript No. JOB-22-58353 ; Editor assigned: 26-Mar-2022, PreQC No. JOB-22-58353 (PQ); Reviewed: 07-Apr-2022, QC No. JOB-22-58353; Revised: 09-Apr- 2022, Manuscript No. JOB-22- 58353 (R); Published: 14-Apr-2022, DOI: 10.4172/2322- 0066.10.4.004.
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In humans and other animals, the abdomen (also known as the belly, tummy, midsection, belly, tucky, or stomach) is the part of the body that lies between the thorax (chest) and the pelvis. The abdomen is the front half of the torso's abdominal section. The abdominal cavity refers to the space occupied by the abdomen. It is the body's posterior tagma in arthropods, and it follows the thorax or cephalothorax.
The thoracic diaphragm connects the thorax to the pelvis, while the pelvic brim connects the two. The pelvic brim is the margin of the pelvic inlet, stretching from the lumbosacral joint (the intervertebral disc between L5 and S1) to the pubic symphysis. The abdominal cavity is the area above this inflow and beneath the thoracic diaphragm. The front of the abdominal cavity is defined by the abdominal wall, while the back is defined by the peritoneal surface.
The abdomen is a huge bodily cavity in vertebrates that is surrounded on both sides by abdominal muscles and on the back by a portion of the vertebral column. Lower ribs can also provide a barrier between the ventral and lateral walls. The abdominal cavity is connected to the pelvic cavity and extends above it. The diaphragm connects it to the thoracic cavity.
The diaphragm is where the aorta, inferior vena cava, and stomach pass through. The parietal peritoneum is a serious membrane that lines the abdominal and pelvic cavities. The visceral peritoneum, which lines the organs, is continuous with this membrane. In vertebrates, the abdomen houses a variety of organs, including those of the digestive, urinary, and muscle function.
Most of the digestive system's organs, including the stomach, small intestine, and colon with its connected appendix, are located in the abdominal cavity. The liver, gallbladder, and pancreas are among the accessory digestive organs, and they connect with the rest of the system via numerous ducts. The spleens, as well as organs of the urinary system such as the kidneys and adrenal glands, as well as many blood veins such as the aorta and inferior vena cava, are all located within the abdomen. The urinary bladder, uterus, fallopian tubes, and ovaries can all be classified as abdominal or pelvic organs. Finally, the peritoneum is a large membrane found in the abdomen. A pericardial fold may entirely cover some organs, while only one side of organs that are closer to the abdominal wall may be covered. The kidneys and ureters are called retroperitoneal organs because they are located in the retro peritoneum.
Some animals' abdominal organs are highly specific. Ruminants' stomachs, for example, are separated into four chambers: rumen, reticulum, omasum, and abomasum (a suborder of mammals that includes cattle and sheep). The abdominal wall is made up of three layers of muscles. External oblique, internal oblique, and transverse abdominal are the three types, from outside to inside. Between the spinal column, the lower ribs, the iliac crest, and the pubis of the hip are the first three layers. Their nerves all converge at the midline and form a sheath around the rectus abdominis before merging on the opposing side at the anterior surface. The external oblique, which runs downward, and forward, the internal oblique, which runs upward and forward, and the transverse abdominal, which goes horizontally forward, produce strength.
The fibres of the transverse abdominal muscle run horizontally and are flat and triangular. It's located between the internal oblique and the transverse fascia beneath it. The inguinal ligament, costal cartilages 7–12, iliac crest, and thoracolumbar fascia all contributes to it. Inserts into the pubic crest, xiphoid process, linea alba, and conjoint tendon.