Urogenital System

Learning & Test Objectives

  1. Components of the urinary and genitals systems individually and as a unit at the gross level as well at the microscopic anatomy level.
  2. Retroperitoneum & Pelvis topographies.
  3. Pelvic floor muscles, perinela muscles and compartmentalization.   
  4. Urinary tract parts and course plus constrictions and dilations sites.
  5. Development of the urogenital system and gonadal embryogenesis (anatomical basics).
  6. Anatomy of the nephron system.
  7. Anatomy of the micturition reflex.
  8. Functional anatomy of testes and ovaries.

Description of the test

The test is held by the general rules of written tests (see Continuous Testing – Organisation).

The test of the urogenital system is in written format and follows the general rules for written tests (see continuous testing – organisation). The main topics of the test are the general structure of the urinary and genital systems, the structure, location, syntopy, blood supply and innervation of their individual organs and the muscles of pelvic floor as well as perineal muscles. For each organ is necessary to know the supplying arteries and their source and the draining veins and lymphatic vessels. Increased attention must be given to the lymphatic drainage of the scrotum, testes, prostate, ovaries, uterus and vagina. The test may also include questions on topography of the retroperitoneum and male/female pelvis, basic histological structure and development of the urogenital organs, projection of organs, muscles of the pelvic diaphragm, perineal muscles, ishcioanal fossa, clinical notes, other interesting notes and radiological images. At the end of the test the student must draw and describe one of the required schemes (listed below).

 

Clinical notes

Renal artery stenosis is a narrowing of the renal artery. Decreased blood flow in the renal vascular bed disrupts the regulation of blood pressure and can result in hypertension.

A floating kidney (ren migrans / nephroptosis) describes a situation in which the renal capsule is weakened due to an excessive loss of perinephric fat (extreme weight loss), and the kidney descends within the retroperitoneal space to the pelvic cavity. Although the renal vessels descend with kidney, their origin remains at the level of vertebra L2.

An ectopic kidney is a kidney located in an abnormal position. It results from failure of the kidney to reach its normal position during development and is usually located more caudal than the normal position. Its arteries arise from the aorta at the corresponding level.

A transplanted kidney is usually positioned in the right iliac fossa. It is more common than an ectopic or floating kidney in the same location.

Hydronephrosis describes a situation where the renal pelvis is dilated due to either obstruction in the flow of urine or upstream flow of urine from the urinary bladder to the ureters and renal pelves and calices.

The female urethra is short and in close proximity to the rectum. This is why females have a higher incidence of urinary tract infections than males.

The external urethral sphincter in males is the main mechanism for providing continence. During prostate and urinary bladder surgery, it may be damaged, which can lead to urinary incontinence.

Due to the origin of the testis in the retroperitoneal space, it is necessary to check the retroperitoneal lymph nodes for potential metastases as a part of surgical treatment of testicular tumors.

Testicular torsion describes an acute situation when the testis twists around the vessels passing in the spermatic cord. The symptoms are swelling of the scrotum, intense pain projecting to the inguinal region and nausea. It usually occurs in adolescent males and requires urgent surgical treatment to prevent complete necrosis of the testis. After 12 hours, the testis is usually irreversibly damaged and it is necessary to remove them.

Varicocele is a term describing dilation of the pampiniform plexus inside the spermatic cord. In young males, the cause remains unknown. In older men varicocele may arise as a result of impeded blood flow caused by various renal diseases and tumors. It is one of the most common causes of male infertility, as the impeded blood flow results in an increase in temperature inside the testis. Varicocele occurs more commonly on the left side, since the left testicular vein drains into the left renal vein perpendicularly.

Benign prostatic hyperplasia is characterised by an increase in number of the submucosal prostate glands. This leads to the enlargement of transitional zone, which can lead to obstruction of urinary flow. The enlarged transitional zone compresses the fibromuscular stroma of the peripheral zone, eventually transforming it into the ‘surgical’ capsule of the prostate. This allows surgical enucleation of transitional zone, sparing the peripheral part.

Carcinoma of the prostate is a malignant neoplasia arising in the glandular epithelium of the peripheral zone or, less commonly, in the central or transitional zones.

A hydrocele is an enlargement of the scrotum caused by accumulation of fluid inside the vaginal cavity of the testis. A congenital hydrocele results from a persistent communication between the peritoneal cavity and the layers of the scrotum via a patent vaginal process of peritoneum. An acquired hydrocele can occur as result of inflammation of the testis or epididymis or from a tumour. However, in the majority of cases, its cause remains unknown.

Cabanas' lymph node (nodus lymphoideus inguinalis superficialis superomedialis) is the sentinel node of the skin of the penis.

Clinically, the urethra can be divided in two parts: the anterior and posterior parts. From the anatomical point of view, the posterior urethra consists of the intramural part, prostatic urethra and membranous urethra. The anterior urethra consists of the spongy urethra.

Epispadias is a rare atypical location of the external urethral orifice on the dorsum of the penis (1:30000).

Hypospadias is a more common atypical location of the external urethral orifice on the ventral (urethral) surface of the penis (1:300).

Ectopic pregnancy (graviditas extrauterina / GEU) occurs when a zygote (a fertilised ovum) implants in a different location than its normal implantation site within the uterus. This occurs most commonly within the uterine tube. However, other locations, such as the cervical canal, ovary or peritoneal cavity are possible. In the majority of cases the embryo does not survive. However, sometimes its development may continue and it may rupture the uterine tube causing life threatening bleeding and sepsis.

A myoma / leiomyoma is a benign tumor of the myometrium. It is the most common tumour of the body of the uterus. Its symptoms include long heavy bleeding that occurs independently from menstrual bleeding.

The recto-uterine pouch/pouch of Douglas is a clinically important place for palpation and evacuation of fluid that has accumulated inside the peritoneal cavity.

Episiotomy is a surgical incision of the perineum during labour to prevent uncontrolled injury of the vagina, perineum and the baby. Mid-line episiotomy crosses the perineal body, medio-lateral episiotomy (30° from the midline) cuts through the 3 bulbospongiosus and the superficial transverse perineal muscle. Left medio-lateral episiotomy is easily sutured, heals faster and therefore is performed more often.

The loose connective tissue of the retroperitoneal space continues smoothly into the connective tissue of the pelvis and lower limbs. It forms an extensive topographical area from the diaphragm to as low as the popliteal fossae. In this cavity, inflammatory processes can spread (tuberculosis in the past).

 

Interesting points

There are approximately 1 to 1.5 million nephrons in a single kidney.

The functional tissue of the ovary is its cortex (cortex ovarii). The functional tissue of the testis is its medulla with the seminiferous tubuli (tubuli seminiferi).

The pampiniform plexus and the testicular veins work as a countercurrent blood cooling system.

The exocervix is the clinical term for the vaginal part of the cervix (portio vaginalis cervicis). Endocervix is the clinical term for the supravaginal part of the cervix (portio supravaginalis cervicis).

The urogenital floor (diaphragma urogenitale) is an obsolete term for the fibromuscular plate formed by the perineal membrane, transverse perinei muscles, ischiocavernosus and bulbospongiosus. In modern anatomy, this term is no longer used, however, it is frequently applied in clinical terminology, which is why we mention it in this text.

 

List of required schemes for drawing

  • Syntopy of the kidney
  • Transverse section of the penis
  • Sagittal section of the male urethra – parts, constrictions and dilations
  • Sagittal section of the male pelvis
  • Sagittal section of the female pelvis
  • Frontal section of the male pelvis

 

Radiological images

Radiological images of urogenital system

Created: 27. 2. 2017 / Modified: / Responsible person: MUDr. Azzat Al-Redouan