How does a rat die of old age? - briefly
Senescence causes progressive failure of vital organs—including the heart, kidneys, and liver—and frequently promotes tumor development, ultimately leading to death. The final stage involves systemic collapse and loss of essential physiological functions.
How does a rat die of old age? - in detail
Rats typically reach the end of their natural lifespan between two and three years. As they age, physiological systems undergo progressive deterioration that culminates in death.
Cellular senescence reduces the capacity for tissue regeneration. Muscle mass declines (sarcopenia), leading to reduced mobility and diminished ability to obtain food. Immune function weakens, making older individuals more susceptible to infections that they would have previously resisted.
Organ systems exhibit characteristic age‑related failures:
- Cardiovascular: arterial stiffness and reduced cardiac output increase the risk of heart failure.
- Renal: glomerular filtration rate falls, impairing waste elimination and fluid balance.
- Hepatic: metabolic clearance slows, resulting in accumulation of toxins.
- Respiratory: lung elasticity decreases, limiting oxygen exchange.
Neoplastic growth becomes more common with advancing age. Tumors in the liver, lungs, or gastrointestinal tract often develop unchecked due to impaired immune surveillance, eventually causing organ compromise.
The terminal phase is marked by:
- Progressive weight loss and cachexia.
- Marked lethargy and reduced response to stimuli.
- Diminished grooming, leading to coat deterioration.
- Failure of one or more vital organs, often precipitated by infection, tumor burden, or cardiac collapse.
These processes collectively drive the cessation of life in aged rats, reflecting the integrated decline of multiple biological systems.