question: How does semen and urine travel through the same hole?
comment: Imagine a tube shaped like a Y. Two different input streams that eventually feed to one output
passages: The ureter has a diameter of but there are three constrictions, which are the most common sites of renal calculus obstruction:
  
  BULLET::::1. at the pelvi-ureteric junction (PUJ) of the renal pelvis and the ureter
  
  BULLET::::2. as the ureter enters the pelvis and crosses over the common iliac artery bifurcation
  
  BULLET::::3. at the vesicoureteric junction (VUJ) as the ureter obliquely enters the bladder wall
  
  Section::::Structure.:Blood supply.
  
  The ureter has an arterial supply which varies along its course.
  
  BULLET::::1. The upper part of the ureter closest to the kidney is supplied by the renal arteries
   BULLET::::2. The middle part of the ureter is supplied by the common iliac arteries, direct branches from the abdominal aorta, and gonadal arteries (the testicular artery in men or ovarian artery in women)
  
  BULLET::::3. The lower part of the ureter closest to the bladder is supplied by branches from the internal iliac arteries, as well as:
  
  Within the periureteral adventitia these arteries extensively anastomose thus permitting surgical mobilization of the ureter without compromising the vascular supply as long as the adventitia is not stripped. Lymphatic and venous drainage mostly parallels that of the arterial supply.
  
  Section::::Structure.:Nerve supply.
   The urethra, which is the last part of the urinary tract, traverses the corpus spongiosum, and its opening, known as the meatus , lies on the tip of the glans penis. It is a passage both for urine and for the ejaculation of semen. Sperm are produced in the testes and stored in the attached epididymis. During ejaculation, sperm are propelled up the vas deferens, two ducts that pass over and behind the bladder. Fluids are added by the seminal vesicles and the vas deferens turns into the ejaculatory ducts, which join the urethra inside the prostate gland. The prostate as well as the bulbourethral glands add further secretions, and the semen is expelled through the penis.
   Section::::History.
  
  The first flow-through test was developed in 1985 to test for the presence of beta-human chorionic gonadotropin in urine.
  
  Section::::Principle of flow-through tests.
   Most vertebrates have some form of duct to transfer the sperm from the testes to the urethra. In cartilaginous fish and amphibians, sperm is carried through the archinephric duct, which also partially helps to transport urine from the kidneys. In teleosts, there is a distinct sperm duct, separate from the ureters, and often called the vas deferens, although probably not truly homologous with that in humans. The vas deferens loops over the ureter in marsupials, but not in placental mammals.
   NGU is transmitted by touching the mouth, penis, vagina or anus by penis, vagina or anus of a person who has NGU.
   In males, the semen is forming in the testis. The sperm structure of "Theodoxus fluviatilis" was examined by Gustaf Retzius. Then semen travels through the prostate, where it mixes with prostatic fluid. Finally it goes through the vas deferens to the penis. The penis is located on the inner side of the right tentacle.
  
  The following illustrations show the reproductive system in the female and in the male:
  
  Section::::Description.:Various organ systems.
   Section::::Mechanism of secretion and membrane transfer.
   Vertical ciliary tracts in the grooves between adjacent abdominal segments move particles toward the abdominal fecal groove. Once in the abdominal fecal groove, further ciliary currents transport particulate matter (feces, gametes, etc.) from the depths of the tube, through the thoracic segment to the aperture where it can be released to the sea.
  
  Section::::Physiology.
  
  Section::::Physiology.:Circulatory system.
  
  Section::::Physiology.:Circulatory system.:Vasculature.
   BULLET::::- Coitus interruptus (withdrawal). With this technique, the man removes his penis from the vagina near the end of intercourse and ejaculates into a wide-necked cup or bottle.
   Urogenital opening
  
  The urogenital opening is where bodily waste and reproductive fluids are expelled to the environment outside of the body cavity. In some organisms, including birds and many fish, discharge from the urological, digestive, and reproductive systems empty into a common sac called the cloaca.
  
  In placental mammals, these three systems are more separated. In females, separate orifices have evolved for all three, while in males, a common urinary meatus discharges both urine and semen from the urethra.
   A urine collection device allows an individual to empty his or her bladder into a container hygienically and without spilling urine.
  
  Section::::Description.:Condom catheters.
   BULLET::::- Urinary incontinence: leakage of small amounts of urine is common in the last part of pregnancy
  
  BULLET::::- Normal vaginal secretions of pregnancy
  
  BULLET::::- Increased sweat or moisture around the perineum
  
  BULLET::::- Increased cervical discharge: this can happen when there is a genital tract infection
  
  BULLET::::- Semen
  
  BULLET::::- Douching
  
  BULLET::::- Vesicovaginal fistula: an abnormal connection between the bladder and the vagina
  
  BULLET::::- Loss of the mucus plug
  
  Section::::Prevention.
   BULLET::::- Indiana pouch. A pouch is constructed using the end part of the ileum and the first part of the large intestine (cecum). The remaining ileum is first attached to the large intestine to maintain normal digestive flow. A pouch is then created from the removed cecum, and the attached ileum is brought to the surface of the abdominal wall to create a stoma.
   BULLET::::- Collecting duct: The collecting duct receives liquid between 100 mOsm if no re-absorption is done, to 300 or above if re-absorption was used. The collecting duct may continue raising the concentration if required, by gradually pumping out the same ions as the Distal convoluted tubule, using the same gradient as the ascending limbs in the loop of Henle, and reaching the same concentration.
  
  BULLET::::- Ureter: The liquid urine leaves to the Ureter.
  
  BULLET::::- Same principle is used in hemodialysis within artificial kidney machines.
  
  Section::::Countercurrent exchange in biological systems.:Countercurrent multiplication loop.:History.
   In cartilaginous fishes, the part of the archinephric duct closest to the testis is coiled up to form an epididymis. Below this are a number of small glands secreting components of the seminal fluid. The final portion of the duct also receives ducts from the kidneys in most species.
  
  In amniotes, however, the archinephric duct has become a true vas deferens, and is used only for conducting sperm, never urine. As in cartilaginous fish, the upper part of the duct forms the epididymis. In many species, the vas deferens ends in a small sac for storing sperm.
   Section::::Flow.
  
  Let A and B be the two hosts, each in its own private network; N and N are the two NAT devices with globally reachable IP addresses EIP and EIP respectively; S is a public server with a well-known, globally reachable IP address.
  
  BULLET::::1. A and B each begin a UDP conversation with S; the NAT devices N and N create UDP translation states and assign temporary external port numbers EP and EP
  
  BULLET::::2. S examines the UDP packets to get the source port used by N and N (the external NAT ports EP and EP)
   Section::::Fluid transport across cells.
   In 1974, he and his graduate student, Mary Green, along with Paul Heidger, a faculty collaborator, published two landmark companion papers in the journal "Infection and Immunity". The papers detail how L-form bacteria inside an experimental human embryonic kidney tissue culture system are able to persist in cells and explains how they are able to revert into the cell wall-containing parent bacterial form. They also proposed a detailed reproductive cycle for L-form bacteria, followed by electron microscopy of the microorganisms.
   Alfred Kinsey measured the distance of ejaculation, in "some hundreds" of men. In three-quarters of men tested, ejaculate "is propelled with so little force that the liquid is not carried more than a minute distance beyond the tip of the penis." In contrast to those test subjects, Kinsey noted "In other males the semen may be propelled from a matter of some inches to a foot or two, or even as far as five or six and (rarely) eight feet". Masters and Johnson report ejaculation distance to be no greater than . During the series of contractions that accompany ejaculation, semen is propelled from the urethra at , close to .
   In a typical sexual intercourse, the female approaches the male from the back, lengthening her legs towards his gaster, while the male extends the aerial display, often moving in a zigzag pattern. At this point in time, the female lands on the hover site and repeatedly touches the surface of the site with the tip of her gaster. The male then quickly touches the female’s back with his legs, grabs her chest for a few seconds, and establishes a genital connection for about 2–25 seconds. After the intercourse, the female will clear her genital area with her legs.
   BULLET::::3. S passes EIP:EP to B and EIP:EP to A
  
  BULLET::::4. A sends a packet to EIP:EP.
  
  BULLET::::5. N examines A's packet and creates the following tuple in its translation table: (Source-IP-A, EP, EIP, EP)
  
  BULLET::::6. B sends a packet to EIP:EP
  
  BULLET::::7. N examines B's packet and creates the following tuple in its translation table: (Source-IP-B, EP, EIP, EP)
   Since urine flow is determined by the rate at which plasma is cleared of solutes and water (as discussed above), urine flow (V) is given as the sum of osmolar ("C") and free water clearance ("C"):
  
  Rearranging yields "C"
  
  Since osmolar clearance is given as the product of urine flow rate and the ratio of urine to plasma osmolality, this is commonly represented as
  
  For example, for an individual with a urine osmolality of 140 mOsm/L, plasma osmolality of 280 mOsm/L, and a urine production of 4 ml/min, the free water clearance is 2 ml/min, obtained from
  
  Section::::Interpretation.
   BULLET::::- External sphincter muscle of female urethra
  
  BULLET::::- Compressor urethrae muscle in the female is sometimes included
  
  BULLET::::- Urethrovaginal sphincter in the female is sometimes included
  
  BULLET::::- other
  
  BULLET::::- Membranous urethra in the male; proximal portion of urethra in the female
  
  BULLET::::- Bulbourethral gland (males). The Bartholin gland, the female counterpart is in the superficial perineal pouch
  
  BULLET::::- Vagina (females)
  
  Section::::"Urogenital diaphragm".
   BULLET::::- According to Samad, the patient claimed "the fish had darted out of the water, up the urine stream, and into his urethra." While this is the most popularly known legendary trait of the candiru, according to Spotte it has been known conclusively to be a myth for more than a century, as it is impossible because of simple fluid physics.
  