Bladder

The bladder is a hollow organ located in the lower abdomen, responsible for storing urine before it is eliminated from the body.

ANATOMY

An adult bladder can only hold about 16 oz. (0.45 kgs) before urging its owner to go, but at night, it can hold twice that before waking its owner up.

The bladder is made up of smooth muscle tissue known as the detrusor muscle, which contracts to expel urine during urination.

The sensation of needing to urinate is triggered when the bladder reaches about half of its capacity, sending signals to the brain that it's time to find a restroom.

The average person urinates about 6-8 times a day, depending on factors such as fluid intake, diet, and overall health.

Incontinence is a condition characterized by the inability to control urine flow from the bladder. It can occur due to various factors, including weakened pelvic floor muscles or nerve damage.

The muscular sphincter at the base of the bladder, called the urinary sphincter, helps control the flow of urine. It relaxes during urination and contracts to prevent leakage between bathroom visits.

The bladder is closely connected to the kidneys, as it receives urine from the kidneys through two tubes called ureters. These tubes transport urine to the bladder for storage.

ANIMAL BLADDERS

Besides humans, many mammals have bladders that serve the purpose of storing and releasing urine. The size and capacity of the bladder vary among species depending on their physiological needs. For example, the bladder of a small rodent like a mouse would be significantly smaller than that of a larger mammal like a whale.

Scientists have found that all mammals weighing more than 2.2 pounds (a kilogram) empty their full bladders in about 20 seconds.

Most fish have a swim bladder, also known as an air bladder, which helps them control their buoyancy. It is a gas-filled organ that allows fish to adjust their depth in the water without having to constantly swim. By inflating or deflating the swim bladder, fish can either increase or decrease their overall density and achieve neutral buoyancy.

Amphibians, such as frogs and toads, have a urinary bladder that functions similarly to the human bladder. It stores urine produced by the kidneys before being eliminated. Amphibians also utilize their skin as a secondary organ for waste elimination.

Reptiles, including snakes, lizards, and turtles, have a bladder that acts as a reservoir for urine. Like amphibians, reptiles can excrete waste through their bladder and their skin.

Birds, unlike mammals, do not possess a urinary bladder. This adaptation is due to their lightweight body structure and the need to reduce weight for flight. Instead, birds excrete waste as a semi-solid substance called uric acid, which eliminates the need for water storage in a bladder.

BLADDER INFECTIONS

Bladder infections are more common in women than in men. This is because women have a shorter urethra, which makes it easier for bacteria to travel from the vagina to the bladder.

The cause of death of famous Danish astronomer Tycho Brahe is believed to be from a bladder infection after politeness kept him from excusing himself to use the bathroom during a royal banquet in October 1601, causing his bladder to rupture. He died 11 days later.

A Dutch man named Jan de Doot, in 1651, removed his own bladder stone with a kitchen knife. He pulled it out through an incision he made in his perineum. It was the size of an egg and weighed a quarter of a pound. He lived for years after, and had the stone plated in gold.