Gross Anatomy of the Urinary Bladder

Gross anatomy, anatomical relations, blood supply, and innervation of the human urinary bladder as detailed by Dr. Mahvish Javed.

Kidneys

The two organs that perform all urinary system functions except for the actual excretion of urine.

Ureters

The two tubes that convey urine from the Kidneys to the Urinary Bladder.

Space of Retzius

The anterior prevesical space or retropubic space that separates the adult bladder from the pubic symphysis.

Urachal remnant

Also known as the medial umbilical ligament, it courses from the apex of the bladder along the anterior abdominal wall to the umbilicus.

Transitional epithelium

The specific type of tissue that lines the body of the urinary bladder.

Bladder Capacity

The urinary bladder can typically hold between $400\,ml$ to $1000\,ml$ of urine.

Lesser pelvis

The anatomical location of the adult urinary bladder when it is empty.

Greater Pelvis

The region the bladder enters as it fills with urine.

Apex

The part of the bladder directed anteriorly toward the umbilicus, connected by the median umbilical ligament.

Fundus

Also called the base of the bladder, it is shaped like an inverted triangle and faces postero-inferiorly.

Neck

The lowest portion of the bladder, or inferior angle, through which the urethra arises.

Trigone

A smooth triangular part of the bladder fundus firmly attached to the underlying wall and formed by the right and left ureteral orifices.

Ureteral Orifices

Slit-like openings where the ureters enter the bladder on the posterolateral angles of the trigone.

Bar of Mercier

Also called the Interureteral Fold, it is the mucous membrane present between the two ureteral orifices.

Internal Urethral Sphincter

A smooth muscle at the junction of the urethra and bladder innervated by $S2-S4$ nerves; it prevents urine leakage and retrograde ejaculation of semen.

Detrusor Muscle

Also referred to as Muscularis Propria, this smooth muscle comprises inner and outer longitudinal layers and a middle circular layer.

Vesicouterine pouch

Also known as the anterior cul-de-sac, it is the posterior peritoneal reflection in females continuous with the uterus and vagina.

Superior vesical artery

A branch of the internal iliac artery that supplies the anterosuperior parts of the bladder.

Vaginal arteries

In females, these arteries replace the inferior vesical arteries and supply the posteroinferior parts of the bladder.

Pelvic Nerve

A parasympathetic nerve from the sacral region of the spinal cord that causes contraction of the Detrusor muscle.

Pudendal nerve

A somatic nerve that causes contraction of the External Sphincter to hold urine.

Hypogastric nerve

A sympathetic nerve that causes relaxation of the Detrusor muscle and contraction of the Internal sphincter.

Vesical venous plexus

The venous network that drains from the bladder into the internal iliac veins.

External iliac lymph nodes

The lymph nodes that receive lymphatic vessels leaving the superior surface of the bladder in both sexes.