The urogenital system
The urinary system is related to the genital system both in male and female. The urinary system is composed of two kidneys, two ureters, bladder, penis including urethra in the male and the urethra in the female. The genital system is composed of the two testis, the two epidedymis, the two vas deferens (sperm stings), the two seminal vesicles, the two ejaculatory ducts and the prostate.

The female genital system is composed of  the two ovaries, the two fallopian tubes, the uterus, the vagina and the enteriotus. The genital system is controlled by the pituitary gland the adrenal gland in both sexes and the sertoli cells of the testis in the male and the ovarian cells in the female. Both systems are related to a common tract, the urethra, and they are related in their innervations, arterial supply and venous return. That is why one system may be vulnerable if the other is affected.

To understand the urinary system, please consider the following simplification: The kidney plays the role of a filtration apparatus which filtrate the blood pumped by its arteries to separate urine. The urine is transferred through pipes known as the ureters to the reservoir (the bladder) where it is stored until it is evacuated through the draining pipe (the urethra) to the outside.

The kidney:
It has a characteristic shape, situated in the flanks under the liver on the right side and the spleen on the left side and hence the characteristic site of the renal colic. They are supplied by the renal artery directly from the aorta and drained to the vena cava through the renal veins. The lymph drainage is along sides of the aorta. The kidney is composed of a solid substance called the cortex (outer part) and medulla (inner condensed part made of tubules). The medulla opens in the calices which unite to form the renal pelvis, a triangular reservoir which collects the urine in the ureters.

The kidney contains the units of blood filtration to produce urine they are about 2 million units (nephrons). It is supplied with blood in a very high pressure that should exceed 100mmgh. This means it receives 1500 liters of blood every 24 hours (20% of the blood volume pumped by the heart every minute). It filters the blood constituents in a selective manner to reabsorb some of the high molecular weight particles as well as electrolytes, glucose and urea and regulate the potassium, kreatinin and others. The kidney is also affected by the anti diuretic hormone which regulates the water secretion and re absorption to keep the body constantly hydrated.

The kidney may be affected by diseases like trauma, infection, stone formation, cysts, tumors and congenital malformations (born defects). It my also be affected by renal high blood pressure (renal hypertension), metabolic disease or secondarily as a result of obstruction of the ureters. The obstruction of the ureters may lead to increased pressure inside the collecting system which may reduce the function the of the kidney if the system is not released by a catheter or puncture.

The ureter:
The ureters are bilateral tubes made of smooth muscles and fibers. They connect the kidneys (renal pelvis) to the bladder. They run through the abdomen behind the peritoneum alongside of the tips of the lateral wings of the vertebrae to sink inside the pelvis and join the bladder. They end in the bladder through a valve-like structure that keep them closed during the evacuation of the bladder. The ureters transport the urine as separate drops through its propulsive contractions to the bladder.They are supplied with innervations that is strictly related to the testis. That is why a ureteric colic resulting from a stone may be related with testicular pain. They also run above a part of the fallopian tubes which explains the ovarian pain related to ureteric stones and the ureteric pain related to the ovarian disease. The blood supply of the ureters is variable. The ureters are vulnerable to stones which may obstruct them. They may be also affected by narrowing (obstruction) related to pressure from the surrounding organs or from tumors of the wall of the ureter or its lining.

The bladder:
This unique muscular organ is situated at the floor of the pelvis, namely its muscles. The bladder receives the urine through the ureters. It stores up to a capacity of 500ml. When contracts, it evacuates the urine through the urethra to the outside allowing only a residual urine between 0-50ml. When the bladder fills to its maximum capacity, it elevates the peritoneum and can be palpated behind the muscle wall of the lower abdomen where it can be punctured for its evacuation through a suprapubic catheter.

The bladder ends by the bladder neck, a muscular condensation that closes when it is empty and during ejaculation to prevent escape of sperms inside the bladder. The bladder neck rests on the base of the prostate and it demarcates the beginning of the urethra. The bladder is innervated by the nerves of the lower segments of the spinal cord and is also under control of the higher centres of the brain. These centres reach their maturity after one year of birth. This is why it is expected for a child to socially be able to control his bladder starting from this age. The injury of these higher centres leads to a self controlling (automatic) bladder and sometimes to a spastic bladder while injury to the lower centres results in loss of control of urine and to a flaccid bladder. The blood supply of the bladder is from the main arteries  of the pelvis. The veins follow the same route. The bladder fills with 60 ml of urine every hour and the rhythm of its evacuation is nearly every 3-4 hours.Normally it does not disturb the sleep and perhaps it evacuates once at night, usually very early in the morning. The lymph drainage of the bladder is to the big veins of the pelvis. The urinary bladder has a very special lining which plays a role in the development of cancer and the protection of the bladder from the invasion of bacteria through its protective lining layer.

The diseases that may affect this organ are infection, stones, cancer, functional diseases related to its reservoir and evacuation function and changes in its wall related to affection of the nearby organs or the very related prostate.

The urethra:
This is the connection between the bladder and the outside. It is lined by a protective lining of cells starting from the bladder neck to the external orifice. The urethra runs inside the lower spongy body of the penis (corpus spongiosum). It is surrounded by the prostate in its first part (prostatic urethra) followed by the muscles of the floor of the pelvis, the so called external sphincter which is necessary for the voluntary control of urine. It is then surrounded by the muscles of the corpus spongiosum along its course. The diameter of the urethra varies at its different parts. Its length in the male is about 18 cm and in the female is about 4,5 cm. It receives the ejaculatory duct son top of an elevation called the Colliculus Seminalis in the male. It is innervated by the nerves coming from the pelvis and related to the lower segment of the spinal cord.The blood supply is coming also from the pelvis. The urethra is the only natural way for endoscopic examination and treatment where instruments are inserted up stream to the bladder and the kidneys through the ureters.

The diseases that may affect this organ are the narrowing of the urethra (stricture), stones, Condyloma (virus infection) or rarely tumors. The born defects or the failure of development of a part or all of the urethra is known as hypospadius and is a common disease of children in some parts of the world. The first part of the urethra passes from inside the pelvis to the outside underneath the pubic bones. It is vulnerable to traumatic injuries during its course in this place.

The penis:
This is the pendular part of the urinary tract which is composed of three bodies; one lower called the spongy body which is surrounded by circular muscles and contains the urethra and two upper bodies each is called the corpus cavernosum. Each corpus cavernosum is made of a tube of tough fibrous tissue of white glistening color called the tunica albugenia (the white investment).

The corpus cavernosum is filled with sponge like tissue which contains smooth muscles and special blood lakes. The penis is innervated by the nerve of the penis which is related to the lower part of the spinal cord. The blood supply of the penis is related to the vessels of the pelvis. The vein system of the penis is very complicated. It is connected to the veins of the front surface of the prostate and the vein network of the pelvis. The veins of the penis have valves that close to prevent the return of the blood to the body during erection.

For erection to take place, stimulation of the penis through the nerves is the first step. The smooth muscles of the corpus cavernosum relax under the effect of some substances leading to filling of the spongy tissue with blood under a pressure exceeding the systolic blood pressure. At the same time the valves of the veins close to prevent the return of  the engorged blood to the body leading to erection.

Any factor disturbing the anatomical structures of the penis may affect erection. The diseases which may affect the organ are infection, impotance, cancer, trauma or venereal diseases. That is why it is important to enjoy a healthy sex through a safe sex..

Priapism is a state of permanent erection which is painful and may lead to complete loss of the erection. It should be treated as an emergency. The erection, whether naturally or drug induced, should not last for more than 4 hours after which urological advise must be looked for.

The scrotum:
This is the fibro muscular sac that includes the testicles. The wall of the scrotum is lined by a muscle called the dartos. It may be very active under the change of temperature to push the testicles upwards and results in decreasing the size of the scrotum. the ascend of the testicle may result from its pull by the muscle of the testicular cord (dartos). This may be painful sometimes. The sac is divided by a septum into two compartments, each includes a testis.

The diseases of the scrotum are very related to the testicles. The scrotum may be infected, enlarged as in case of the infection of the epidedymis, collection of serum in the coverings of the testis (hydrocele) or testicular tumors. The sac may also suffer venereal diseases. One of the most agonizing diseases of the scrotum is the descent of the abdominal contents inside it (hernia) which may need surgical correction.

The prostate:
The prostate is the male gland situated  underneath the bladder neck and resting on the muscles of the pelvic floor. It surrounds a part of the urethra (the prostatic urethra).

It is composed of two lateral lobes, a median lobe and the so called seminal Colliculus. This is a small rounded part at the tapered region of the prostate distally situated where the semen ejects during ejaculation and is considered as the lowest limit of the prostate during operations. The organ is surrounded by a capsule of fibro muscular origin.

The prostate is responsible for the secretion of the largest part of the semen. It is highly influenced by the male hormone testosterone. It enlarges at aging as a natural aging process causing trouble at micturition. The mechanism of enlargement is not yet understood. It is supplied by the blood vessels of the pelvis and innervated from the lower segment of the spinal cord. The seminal vesicles which are two ampullary structures behind the prostate are connected to the Colliculus by two ejaculatory ducts through the semen ejects to the urethra.

The most  common diseases of the prostate are the benign enlargement, infection (prostatitis), cancer. The benign enlargement takes place in the substance of the lobes of the prostate while the cancer appears in the capsule. This is why the removal of the  enlarged inside core of the prostate in case of its benign enlargement does not prevent the development of cancer of the prostate in its capsule which is left behind.

The reproductive system:
The reproductive system of the man is composed of 2 testicles situated in the
testicular sac (the scrotum). They are followed by the epidedymis which tubes unite to form the vas. The vas  connects the extra abdominal part of the reproductive system to the intra abdominal one. It runs with the testicular vessels surrounded by a special investing muscle called the cremaster muscle through the inguinal canal and to unite with the seminal vesicle behind the prostate on both sides. These evacuate  through the ejaculatory duct and through the elevation situated at the tip of the prostate intera urethral  (Colliculus Seminalis) into the urethra and to the outside.

The testis:
It is an oval organ situated inside the scrotum. It is limited by a capsule and is divided into many partitions which are filled with the cells producing the sperms and those producing important regulatory hormones like testosterone. They are connected to the epidedymis. It is supplied with blood through the testicular artery and is drained through the testicular veins. These veins may widen to produce the so called varices of the testis.

The epidedymis:
This is a  long spiral tube which plays as a passage for the sperms from the testicles to the vas. It is very important because some important development of the sperms takes place inside it.

The vas:
It is a fibro muscular tube and is the route of connection between the urethra and the epidedymis. The is the descending route of infection to develop inflammation of the epidedymis (Epidedymitis). It is also the route of the sperms to ascend to the seminal vesicles. This is helped by its very smooth lubricated linings and the contractile power of its muscles. The pressure inside the vas is well regulated. The vas itself is invested from outwards inward with a facial sheath followed by many muscular layers, vessels and nerves and is lined by a smooth, lubricated membrane called the mucous membrane. On a cut section it appears as a tube with a radiating lumen and the wall of this tube is white jelly-like in structure. It is subjected to trauma in its outer part and where it runs in the inguinal canal. On a surface view it looks like a glistening white thin strong rounded structure. It many be subjected to obstruction resulting by birth or developed due to some disease. It is very easy to grasp and feel the vas inside the scrotum by rolling it at the hind part of the scrotum between the thumb and index fingers. This is the place where I feel it for any operation. This is the upper hind part of the neck of the scrotum. The vas is superficial and is only covered by thin skin.

The seminal vesicles:
These are oval structures present behind the prostate which collect the sperms and mix them with a part of the seminal fluid until they evacuate during ejaculation through the ejaculatory duct. They produce and metabolize a special substance (Prostate specific antigen; PSA) which is very related to the prostate and its activity.

The ejaculatory ducts:
These are minute tubes through which the semen spurts from the seminal vesicles to the side openings of the Colliculus Seminalis

The Colliculus Seminalis:
It is a remnant of a developmental structure. It is a lump located inside the urethra at the area of the tapered part of the prostate. It is very related to the muscles closing the urethra and hence regulating continence