What Are the Main Parts and Functions of the Urinary Bladder?
The urinary bladder is a delicate organ of our body, which serves the function of storing urine or waste fluids that come out of the Kidneys. It is a vital organ that can cause trouble, like a stone in the urinary bladder, when not taken proper care of. Situated at the pelvis, near the pubic bone, it is a sac-like structure that facilitates the flow of the urine through expansion and contraction.
We shall focus on the structure of the urinary bladder through a urinary bladder diagram and also try to understand its various parts.
What is the Urinary Bladder?
The urinary bladder is a part of the urinary system that is concerned with the removal of waste products from the body through the medium of urine and the facilitation of blood purification. It is somewhat triangular and has a hollow within itself to allow urine storage. Its features are:
Urinary bladder capacity: It has an average capacity of 500 ml, which can vary from individual to individual.
Contraction and expansion: The muscles in the bladder contract and expand according to the need to facilitate retention or excretion.
Storage time: Generally, a person can hold urine for 5 hours. With more practice, it can extend to 7- 8 hours. However, it is not advisable to do so.
Location: It is located in the lower abdomen, near the pubic bone.
Parts and Structure of Urinary Bladder
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The urinary bladder has the following parts and structures.
The transitional epithelium layer: This is the initial sheath that surrounds the inside of the bladder. This lining tends to expand when the bladder is filled with urine.
Lamina Propia: Lamina propia has nerve endings, adipocytes, fibrocytes, and interstitial cells. They jointly create a matrix.
Muscularis propia layer: It is elastic like a muscle which is also known as a detrusor. It is thick and smooth and is situated beside the Lamina Propia.
Other parts include the perivesical tissue that is composed of fat and blood vessels. It acts as a segregation between the bladder and kidneys. The tubes of the ureter are attached to the bladder directly.
Moreover, the bladder consists of sphincters of two types which act as valves to control the urine flow. The detrusor muscles act to contract them during important situations like continence. If you want to have a clearer view of the structure of the urinary bladder, take a look at the urinary bladder diagram.
Stone in Urinary Bladder
Sometimes, minerals of the urine can start to form a stone inside the bladder. Under inadequate care, they crystallize inside and disrupt the regular flow of urine, thereby causing extreme pain. A major symptom is the inability to urinate. Some other symptoms of having a stone in the urinary bladder are:
Severe to moderate pain in the lower abdomen,
Painful urination
Blood in urine
Extreme discomfort during urination
Peculiar coloured urine that is generally dark.
Smaller stones can be treated with medicines. However, when the stones grow out of control, an operation is the only way out. These stones can be prevented by consuming adequate and clean water every day. Additionally, one should not control urine for extreme durations for long.
FAQs on Urinary Bladder: Structure, Functions, and Importance
1. What is the urinary bladder and where is it located in the human body?
The urinary bladder is a hollow, muscular, and elastic organ that functions as a reservoir for urine before it is expelled from the body. It is a key component of the urinary system. In humans, it is located in the pelvic cavity, situated just behind the pubic bone. Its exact position varies slightly between males and females due to surrounding organs.
2. What is the primary function of the urinary bladder and why is it important?
The primary function of the urinary bladder is to store urine produced by the kidneys, allowing urination to be infrequent and voluntary. This is important because it provides conscious control over the process of micturition (urination), preventing constant leakage. An average adult bladder can comfortably hold between 400 to 600 millilitres of urine.
3. What are the main anatomical parts of the urinary bladder?
The urinary bladder is typically described as having four main parts or surfaces:
- Apex: The top-front part of the bladder, pointing towards the abdominal wall.
- Body: The main, large section of the bladder located between the apex and the fundus.
- Fundus (or Base): The posterior wall of the bladder, which is triangular in shape.
- Neck: The lowest, most constricted part that connects to the urethra.
4. Why is the urinary bladder lined with a special tissue called transitional epithelium?
The urinary bladder is lined with transitional epithelium, also known as urothelium, because of its unique ability to stretch. This tissue allows the bladder to expand significantly to accommodate increasing volumes of urine and then recoil to its original size after emptying. This elasticity is crucial for its function as a storage organ and prevents the urine from leaking back into the bloodstream at high pressure.
5. How does the nervous system control the process of urination?
The process of urination, or micturition, is controlled by the nervous system through a mechanism called the micturition reflex. As the bladder fills, stretch receptors in its wall send signals to the spinal cord. This initiates a reflex that causes the bladder's detrusor muscle to contract and the internal urethral sphincter to relax. However, the brain's cerebral cortex can voluntarily override this reflex, allowing for conscious control over the external urethral sphincter to decide the appropriate time to urinate.
6. What are the key differences in the urinary bladder between males and females?
While the fundamental structure and function of the urinary bladder are the same in both sexes, there are key differences related to its anatomical position and neighbours. In males, the prostate gland lies directly underneath the neck of the bladder. In females, the bladder is located beneath the uterus and in front of the vagina. This proximity means that issues with the uterus or vagina can sometimes affect bladder function, and vice versa.
7. What are some common causes and signs of a urinary bladder infection?
A urinary bladder infection, medically known as cystitis, is most commonly caused by bacteria entering the urethra and travelling up to the bladder. The most common signs and symptoms include:
- A strong, persistent urge to urinate.
- A burning sensation during urination.
- Passing frequent, small amounts of urine.
- Urine that appears cloudy or has a strong odour.
- Pelvic discomfort or pressure.
8. What are the potential health risks of consistently holding urine for too long?
While holding urine occasionally is generally safe, consistently doing so can pose health risks. Regularly ignoring the urge to urinate can weaken the bladder muscles over time, potentially leading to urinary retention. More significantly, it increases the time that bacteria can multiply in the bladder, raising the risk of developing a Urinary Tract Infection (UTI). In extremely rare and severe cases, chronic over-distension can damage the kidneys or even lead to bladder rupture.
