Urinary bladder

1. Human urinary system: 2. Kidney, 3. Renal pelvis, 4. Ureter, 5. Urinary bladder, 6. Urethra. (Left side with frontal section)
7. Adrenal gland
Vessels: 8. Renal artery and vein, 9. Inferior vena cava, 10. Abdominal aorta, 11. Common iliac artery and vein
With transparency: 12. Liver, 13. Large intestine, 14. Pelvis
Male and female urinary bladders in lateral cross-section
Bladder location and associated structures in the male
Calcifications on bladder wall caused by urinary schistosomiasis
Cross-section of the bladder showing a cancer within it. When a cancer occurs it is most likely to be a transitional cell carcinoma.
A diverticulum of the bladder
Urinary bladder (black butterfly-like shape) and hyperplastic prostate (BPH) visualized by medical ultrasound
Vertical section of bladder wall
Layers of the urinary bladder wall and cross-section of the detrusor muscle
Anatomy of the male bladder, showing transitional epithelium and part of the wall in a histological cut-out

Hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination.

- Urinary bladder

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Both an accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation.

Micrograph of benign prostatic glands with corpora amylacea. H&E stain.
Micrograph showing an inflamed prostate gland, found in prostatitis. A large amount of darker cells, representing leukocytes, can be seen. An area without inflammation is seen on the left of the image. H&E stain.
Lobes of prostate
Zones of prostate
Imaging showing the inferior vesical, inferior pudendal and middle rectal arteries arising from the internal iliac arteries.
Image showing the external iliac lymph nodes and their positions around the external iliac artery and vein
Microscopic glands of the prostate

Anatomically, the prostate is found below the bladder, with the urethra passing through it.

Pubic symphysis

Secondary cartilaginous joint between the left and right superior rami of the pubis of the hip bones.

The pubic symphysis sits between and joins of the left and right superior rami of the pubic bones.
Median sagittal section of male pelvis
Median sagittal section of female pelvis
Anterior view of the body pelvis from a dissection. Pubic symphysis anteriorly.

It is in front of and below the urinary bladder.


Serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids.

The peritoneum, colored in blue
Median sagittal section of pelvis, showing the arrangement of fasciæ
Horizontal disposition of the peritoneum in the lower part of the abdomen
Sagittal section through posterior abdominal wall, showing the relations of the capsule of the kidney
Topography of thoracic and abdominal viscera
Horizontal disposition of the peritoneum in the upper part of the abdomen

The structures within the intraperitoneal space are called "intraperitoneal" (e.g., the stomach and intestines), the structures in the abdominal cavity that are located behind the intraperitoneal space are called "retroperitoneal" (e.g., the kidneys), and those structures below the intraperitoneal space are called "subperitoneal" or "infraperitoneal" (e.g., the bladder).

Organ (biology)

Organ is a collection of tissues joined in a structural unit to serve a common function.

Many of the internal organs of the human body
The liver and gallbladder of a sheep
Relationship of major animal lineages with indication of how long ago these animals shared a common ancestor. On the left, important organs are shown, which allows us to determine how long ago these may have evolved.
The flower is the angiosperm's reproductive organ. This Hibiscus flower is hermaphroditic, and it contains stamen and pistils.
Strobilus of Equisetum telmateia
Human viscera

The hollow organs of the abdomen are the stomach, intestines, gallbladder, bladder, and rectum.

Smooth muscle

Involuntary non-striated muscle, so-called because it has no sarcomeres and therefore no striations .

Smooth muscle tissue, highlighting the inner circular layer (nuclei then rest of cells in pink), outer longitudinal layer (nuclei then rest of cells), then the serous membrane facing the lumen of the peritoneal cavity
The dense bodies and intermediate filaments are networked through the sarcoplasm, which cause the muscle fiber to contract.
A series of axon-like swellings, called varicosities from autonomic neurons, loosely form motor units through the smooth muscle.

Smooth muscle is found in the walls of hollow organs, including the stomach, intestines, bladder and uterus; in the walls of passageways, such as blood, and lymph vessels, and in the tracts of the respiratory, urinary, and reproductive systems.


For other uses of "Womb", see Womb (disambiguation).

Image showing different structures around and relating to the human uterus
Different regions of Uterus displayed & labelled using a 3D medical animation still shot
Diagram showing regions of the uterus
Uterus covered by the broad ligament
Schematic diagram of uterine arterial vasculature seen as a cross-section through the myometrium and endometrium
Vessels of the uterus and its appendages, rear view
Transvaginal ultrasonography showing a uterine fluid accumulation in a postmenopausal woman.
Vertical section of mucous membrane of human uterus
Schematic frontal view of female anatomy
Sectional plan of the gravid uterus in the third and fourth month
Fetus in utero, between fifth and sixth months.
Female pelvis and its contents, seen from above and in front
The arteries of the internal organs of generation of the female, seen from behind
Median sagittal section of female pelvis
(Description located on [[:File:Illu female pelvis.jpg|image page]])

The human uterus is located within the pelvic region immediately behind and almost overlying the bladder, and in front of the sigmoid colon.

Pelvic floor

Composed of muscle fibers of the levator ani, the coccygeus muscle, and associated connective tissue which span the area underneath the pelvis.

Female Pelvic MusclesPelvic Muscles (Male Side).pngPelvic Muscles (Female Side) (cropped).pngVesicovaginal Fistula.png
The pelvic floor muscles span the bottom of the pelvis. This image shows the left levator ani from within.

It is important in providing support for pelvic viscera (organs), e.g. the bladder, intestines, the uterus (in females), and in maintenance of continence as part of the urinary and anal sphincters.


Manneken Pis depicts a urinating boy (puer mingens).
The interior of the bladder
Male dog using urine to mark a spot with his scent.
Urinating woman
Urinating man
Painting showing the physician Constantine the African accepting urine samples for diagnosis
Location of external urethral orifice in adult human male
Location of the bladder and urethra in adult human female (sagittal section)
Woodcut of a puer mingens, from the Hypnerotomachia Poliphili, 1499
Public toilet outside the Philadelphia City Hall
Indecency, 1799 by Cruikshank
Woman Urinating, etching, Rembrandt van Rijn, 1631
A man uses a urinal while urinating in a standing position.
Body position taken by a woman for urination into many female urinals: floating half squat or "skier position".
Urination in Greek antique art: Hetaera urinating into a skyphos
A horse urinating while in formation with the Queens Guards
A maned wolf urinating on a tree to mark his territory
A cheetah marking a tree with urine

Urination, also known as micturition, is the release of urine from the urinary bladder through the urethra to the outside of the body.


Liquid by-product of metabolism in humans and in many other animals.

Sample of human urine
The chemical structure of urea
Urine under the microscope
Medical experts have long connected urine colour with certain medical conditions. A medieval chart showing the medical implications of different urine color
A Doctor Examining Urine. Trophime Bigot.
Urine of pregnant women in the first trimester is collected by a company which purifies the fertility hormone hCG from it (Ede, the Netherlands)
Urine after four months of storage, ready to be used in gardening activities (note the colour and turbidity change compared to fresh human urine).
Fresh human urine after excretion
Medieval Welsh text from the Red Book of Hergest on uroscopy, called Ansoddau’r Trwnc (the Qualities of Urine). Opening lines (translated):
Since it is through the qualities of the urine that a person's faults and his dangers and his diseases and his illness can be identified...
Image of two facing pages of the illuminated manuscript of "Isagoge", fols. 42b and 43a. On the top of the left hand page is an illuminated letter "D" - initial of "De urinarum differencia negocium" (The matter of the differences of urines). Inside the letter is a picture of a master on bench pointing at a raised flask while lecturing on the "Book on urines" of Theophilus. The right hand page is only shown in part. On its very bottom is an illuminated letter "U" - initial of "Urina ergo est colamentum sanguinis" (Urine is the filtrate of the blood). Inside the letter is a picture of a master holding up a flask while explaining the diagnostic significance of urine to a student or a patient. HMD Collection, MS E 78.
Dark urine due to low fluid intake.
Dark red urine due to blood (hematuria).
Dark red urine due to choluria.
Pinkish urine due to consumption of beetroots.
Green urine during long term infusion of the sedative propofol.

Urine flows from the kidneys through the ureters to the urinary bladder.


The urethra transports urine from the bladder to the outside of the body. This image shows (a) a female urethra and (b) a male urethra.
The human male urethra laid open on its anterior (upper) surface
Micrograph of urethral cancer (urothelial cell carcinoma), a rare problem of the urethra.
Position of the urethra in males
Transverse section of the penis
Male urethral opening on glans penis
Female urethral opening within vulval vestibule
Muscles of the female perineum
Urethra. Deep dissection. Serial cross section.
Diagram which depicts the membranous urethra and the spongy urethra of a male

The urethra (from Greek οὐρήθρα – ourḗthrā) is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males.