how does the bladder act in elimination?
It holds urine/urea.
The bladder is a hollow muscular organ located in the lower abdomen that plays a crucial role in the elimination of urine from the body. It acts as a storage reservoir for urine produced by the kidneys until it is ready to be eliminated.
Here's how the bladder acts in the elimination process:
1. Urine Production: The kidneys continuously filter waste products and excess fluid from the blood, producing urine. This urine flows through tubes called ureters and enters the bladder.
2. Storage: The bladder can expand and contract due to its muscular walls. As urine fills the bladder, it expands and stretches to accommodate the increasing volume. The bladder's ability to stretch is thanks to its specialized tissue called transitional epithelium.
3. Sensation of Fullness: As the bladder gradually fills with urine, specialized nerve endings in the bladder wall send signals to the brain, causing the sensation of fullness. This sensation prompts us to initiate the process of urination.
4. Control: The bladder is under voluntary control, meaning we can consciously decide when and where to empty it. The brain receives signals from the bladder indicating its fullness and assesses the appropriate time to initiate urination.
5. Elimination: When we are ready to empty the bladder, a coordinated process called micturition, or urination, occurs. During urination, the brain signals the relaxation of the bladder's muscular walls while simultaneously contracting the muscles of the urethra, the tube that carries urine from the bladder to the outside of the body. This relaxation and contraction mechanism allows urine to flow out of the bladder through the urethra and be eliminated from the body.
It's important to note that the control over urination may be impaired in certain medical conditions or during infancy and early childhood. In such cases, the control and coordination between the bladder and the brain may be disrupted, leading to issues such as incontinence or difficulties in bladder emptying.