The human body possesses a remarkable capacity for adaptation, allowing individuals to survive and thrive even after the removal of certain organs. While some organs are necessary for immediate survival, others can be removed due to disease, injury, or donation without ending life. The body often compensates for the absence of these organs.
Understanding Organ Redundancy
The ability of the human body to function without certain organs is rooted in biological redundancy, a design where multiple components can perform similar functions. Paired organs, such as the kidneys, exemplify this principle; if one is lost, the remaining organ can often increase its capacity to take over the workload. Beyond paired organs, some bodily functions are distributed across multiple systems, allowing other organs to compensate for a removed one. The liver and lymph nodes, for example, can assume some of the immune functions typically performed by the spleen.
Organs We Can Live Without
Humans can live without several organs, each with unique implications for the body’s functioning post-removal.
Spleen
The spleen, located in the upper left abdomen, filters blood, removes old red blood cells, and plays a role in the immune system by producing white blood cells and antibodies. It is often removed due to injury, rupture, or certain blood disorders like immune thrombocytopenic purpura (ITP). After a splenectomy, the liver, bone marrow, and lymph nodes take over most of its functions, though individuals may face an increased risk of specific infections.
Kidney
The body can also function effectively with only one kidney. Kidneys filter waste products from the blood and regulate fluid balance. One kidney may be removed due to disease, injury, or for living organ donation. The remaining kidney undergoes a process called compensatory hypertrophy, increasing in size and efficiency to handle the full filtration load. Studies indicate that the remaining kidney can recover approximately 70% of the baseline renal function within a year after donation.
Appendix
The appendix is a small, finger-shaped organ extending from the large intestine, once thought to be entirely vestigial. While its precise function remains debated, it may have some immune tissue. Appendicitis, an inflammation of the appendix, necessitates its removal (appendectomy) to prevent rupture and widespread infection. There are no known long-term adverse health effects associated with its removal, and individuals lead normal lives without it.
Gallbladder
The gallbladder, situated beneath the liver, stores and concentrates bile produced by the liver, releasing it into the small intestine to aid fat digestion. Gallstones are a common reason for its removal (cholecystectomy). After removal, bile flows directly from the liver to the small intestine, allowing continued fat digestion. The body gradually adjusts to this continuous, less concentrated bile flow.
Reproductive Organs
Reproductive organs, such as the uterus, ovaries, and testicles, can be removed for various medical reasons, including cancer, fibroids, or gender affirmation. The uterus is involved in menstruation and pregnancy, while ovaries and testicles produce hormones and gametes. Removal of these organs results in infertility. If ovaries are removed in premenopausal women, it induces immediate menopause, necessitating potential hormone replacement therapy to manage symptoms.
Stomach
Portions or even the entirety of the stomach can be removed in a procedure called a gastrectomy, typically for cancer or severe ulcers. The stomach’s primary role is initial digestion and food storage. After gastrectomy, the small intestine takes on a greater role in digestion, and individuals must adapt to eating smaller, more frequent meals. This adjustment helps manage nutrient absorption and prevents discomfort.
Large Intestine
The large intestine, or colon, absorbs water and forms waste for excretion. It may be partially or totally removed (colectomy) due to conditions like Crohn’s disease or colorectal cancer. The implications vary depending on the extent of removal, sometimes requiring an ostomy (a surgical opening for waste collection) or significant dietary modifications to manage stool consistency and nutrient absorption.
Life After Organ Removal
Adapting to life without a previously present organ involves a series of physiological adjustments and often requires lifestyle modifications. This adaptive process can lead to new routines and considerations for maintaining overall health.
Following the removal of organs like the gallbladder or parts of the stomach or colon, dietary adjustments are frequently necessary. For example, after gallbladder removal, some individuals may experience difficulty digesting fatty foods or develop diarrhea due to continuous bile flow, necessitating dietary changes like avoiding high-fat meals. Similarly, after a gastrectomy, eating smaller, more frequent meals and chewing food thoroughly becomes important to aid digestion and nutrient absorption. Individuals who have undergone colon removal may need to follow a low-fiber diet initially and gradually reintroduce foods to manage bowel movements and prevent discomfort.
Beyond diet, ongoing monitoring and specific care needs are common after organ removal. Individuals without a spleen require vaccinations and may need preventive antibiotics due to an increased infection risk. Those living with a single kidney are advised to maintain a healthy lifestyle, including a balanced diet and regular exercise, to support the remaining kidney’s function. Regular follow-ups with healthcare providers are important to monitor the body’s adaptation and address any long-term effects, ensuring continued well-being.