Anatomy, Abdomen and Pelvis: Bladder

Excerpt

The bladder is a subperitoneal, hollow muscular organ that acts as a reservoir for urine. The bladder is located in the lesser pelvis when empty and extends into the abdominal cavity when full. In children, the bladder is located in the abdomen and does not completely descend into the pelvis until puberty. The bladder is a distensible organ and is typically able to hold up to 500 milliliters of urine.

The size of the pediatric bladder can be predicted by the following: (Age + 2) x 30 mL.

The bladder is situated just posterior to the pubic symphysis. Posteriorly, the anterior wall of the vagina sits behind the bladder in females. In males, the rectum is located posterior to the bladder. Inferiorly, the muscles of the pelvic diaphragm support the bladder. The bladder is a relatively free organ in the subcutaneous fat of the sub peritoneum except for some fixed ligamentous connections at the bladder neck. The superior and part of the posterior surfaces of the bladder are covered by peritoneum. The inferior portion and inferolateral sides of the bladder are covered by endopelvic fascia.

Anatomically, the bladder is contiguous with the ureters above and the urethra below. It is divided into four anatomical parts: the apex or dome, body, fundus, and neck. The apex is the anterosuperior part of the bladder that points towards the abdominal wall. The fundus, or base, is the posteroinferior part of the bladder. The body is the large area situated between the apex and the fundus. The neck of the bladder is the constricted part of the bladder that leads to the urethra.