The urinary bladder (vesica urinaria) is a urinary organ that is a reservoir for urine.

Its capacity in an adult person is 600-750 mL, but this measurement varies for each individual.

The urinary bladder is located in the lesser pelvis behind the pubic symphysis and changes its topography depending on the filling.

Holotopy

It is projected onto the pubic region (in an empty state) of the anterior abdominal wall, while the filled bladder may reach the umbilical region.

Skeletotopy

The empty bladder is located at the level of the pubic symphysis, the filled one may reach the 3rd-4th lumbar vertebrae.

Syntopy

In men, the rectum, seminal vesicles, and vas deferens adhere to the bladder posteriorly; the loops of the small intestine adhere to it superiorly, and the prostate gland adheres to it inferiorly. In women, the cervix of the uterus and vagina are located posteriorly to the urinary bladder, and the fundus and body of the uterus are located superiorly to it.

The urogenital diaphragm (diaphragma urogenitale), which is a muscular and fascial structure in the lesser pelvis, adheres to the urinary bladder inferiorly. It is delimited by the pubic symphysis, as well as by the branches of the pubis and ischium bones.

The space between the anterior surface of the urinary bladder and the pubic area is called the prevesical space (spatium prevesicale) or the space of Retzius.

Parts of the urinary bladder

The urinary bladder has the following parts:

1. The apex of the urinary bladder (apex vesicae), which is a narrowed anterosuperior part

2. The body (corpus vesicae), which is the middle, largest part

3. The fundus (fundus vesicae), which is the inferior, expanded part

4. The neck (cervis vesicae), which is the area of transition to the urethra.

The apex of the urinary bladder is attached to the navel with the median umbilical ligament (plica umbilicalis mediana)

The inferior part of the urinary bladder is supported by the pelvic fascia and the levator ani muscles (m. levator ani)

Men also have the pubioprostatic ligament (lig. puboprostaticum), and women have the pubovesical ligament (lig. pubovesicale), which additionally strengthen the urinary bladder.

Men also have the pubioprostatic ligament (lig. puboprostaticum), and women have the pubovesical ligament (lig. pubovesicale), which additionally strengthen the urinary bladder.

There is dense cellular tissue around the urinary bladder, which also supports the urinary bladder.

Wall of the urinary bladder

The wall of the urinary bladder consists of several layers.

The mucous membrane (tunica mucosa), which is lined with transitional epithelium and has many folds. However, at the fundus of the urinary bladder, there is a region devoid of submucosa, and therefore this region has no folds.

It is called the trigone of the urinary bladder (trigonum vesicae), or Lieto’s trigone.

It forms between the internal urinary meatus and the ureteral orifices.

The muscular coat (tunica muscularis) consists of three layers.

The internal longitudinal layer (stratum internum longitudinale)

The middle circular layer (stratum circulare)

The external longitudinal layer (stratum externum longitudinale)

The most developed is the circular layer, which forms the internal urethral sphincter (sphincter urethrae internus).

In general, all the muscular layers of the urinary bladder form the detrusor muscle (m. detrusor vesicae).

The urinary bladder is covered with the peritoneum (tunica serosa) superiorly.

When it is filled, it is located mesoperitoneally, that is, it is covered with the peritoneum on three sides. An empty bladder lies extraperitoneally, that is, the peritoneum covers it only on one side.

Blood supply

Blood supply to the bladder is carried out by branches of the following arteries:

1. The superior and inferior vesical arteries (aa. vesicales superior et inferior)
2. The middle rectal artery (aa. rectales media)
3. Uterine arteries (aa. uterinae)

Venous drainage

Venous blood drains from the bladder in the following structures:

1. To the venous plexus of the urinary bladder (plexus venosus vesicalis), uterine plexus (plexus uterinus), vaginal plexus (plexus vaginalis), rectal plexus (plexus rectalis)
2. To the internal iliac vein (v. iliaca interna)

Lymph drainage

Lymph drains into the iliac and internal iliac lymph nodes, from where the lymph goes to the lumbar lymph nodes.

Innervation

Innervation of the urinary bladder is performed by the vesical plexus. It is formed by the inferior hypogastric plexuses and internal sacral nerves.

Dictionary

Anatomy of the urinary bladder

Urinary bladder

vesica urinaria

Urogenital diaphragm

diaphragma urogenitale

Superficial transverse perineal muscle

m.transversus perinei superficialis

Ischiocavernosus muscle

m.ischiocavernosus

Deep transverse perineal muscle

m.transversus perinei profundus

Sphincter muscle of the urethra

m.sphincter urethrae

Prevesical space

spatium prevesicale

Apex of the urinary bladder

apex vesicae

Body of the urinary bladder

corpus vesicae

Fundus of the urinary bladder

fundus vesicae

Neck of the urinary bladder

cervix vesicae

Detrusor muscle

m. detrusor vesicae

Triangle of the urinary bladder

trigonum vesicae

Median umbilical ligament

plica umbilicalis mediana

Levator ani muscle

m.levator ani

Lateral pubovesical ligaments

lig.pubovesicale laterale

Medial pubovesical ligaments

lig. pubovesicale medium

Right and left vesicouterine ligaments

lig.vesicouterinum dextrum et sinistrum

Pubovesical muscle

m.pubovesicalis

Superior and inferior vesical arteries

aa.vesicales superior et inferior

Middle rectal arteries

aa.rectales media

Uterine arteries

aa.uterinae

Venous plexus of the urinary bladder

plexus venosus vesicalis

Uterine plexus

plexus uterinus

Vaginal plexus

plexus vaginalis

Rectal plexus

plexus rectalis

Internal iliac vein

v.iliaca interna