The liver is a wedge-shaped (or prism-shaped) accessory organ of the gastrointestinal tract, with its base directed to the right side and its apex facing the left side. The liver appears pinkish brown and is a highly vascular organ. It has a soft and friable consistency.
The liver is the largest organ in the abdominal cavity, accounting for approximately 2-3% of average body weight. It is also the most prominent gland and serves as both an exocrine and endocrine organ. The exocrine function is mostly associated with the synthesis and excretion of bile salts, while the endocrine function is with glycemic control.
Additionally, the liver is also the second-largest organ in the human body after the skin. It is the central organ that is responsible for metabolic homeostasis, regulating the uptake, distribution and digestion of nutrients.
Overall, the liver is a multifunctional and important metabolic organ providing functions that are vital for the entire body. Some of the functions include the following:
- It detoxifies the blood by removing and eliminating potentially toxic substances (i.e.drugs).
- Hepatocytes (liver cells) synthesize numerous proteins (albumins), amino acids (glutamate), enzymes (ALT), and vitamins (vitamin D).
- Some vitamins (vitamins A and B12), glycogen, minerals (iron, zinc), and other nutrients are stored in the liver.
- It is involved in the regulation of coagulation by producing coagulation factors, their inhibitors and many fibrinolytic system components.
- The liver contains phagocytes called Kupffer cells that act against antigens. Therefore, it provides immune function.
- It also produces and secretes a greenish-yellow fluid called bile. The main functions of the bile include aiding in digestion and absorption of lipids and neutralization of gastric acid.
- The fetal liver is responsible for the development of erythrocytes (red blood cells).