Kidneys                                                  accommodate between 600 to 800 ml of
                                                         urine at maximum capacity.
  The kidneys are bean-shaped organs that
   serve several essential regulatory roles in       Urethra
   vertebrates and located in the abdominal
   cavity.                                              It is a tube that conveys urine from the
  The left kidney is located at the vertebral           urinary bladder to the outside of the body.
   level T12 to L3, and the right is slightly           Its wall is lined with mucous membranes
   below the diaphragm and posterior to the              and contains a relatively thick layer of
   liver.                                                smooth muscle tissue.
  The kidneys, unlike the other organs of the          It contains numerous mucous glands,
   abdominal cavity, are located posterior to            called urethral glands that secrete mucus
   the peritoneum and touch the muscles of               into the urethral canal.
   the back.
                                                     Urine
  The kidneys are surrounded by a layer of
   adipose that holds them in place and                 It is a liquid (an aqueous solution)
   protects them from physical damage.                   produced by the kidneys to remove waste
  The kidneys filter metabolic wastes,                  products from the bloodstream.
   excess ions, and chemicals from the blood            It is yellowish in color fluid due to
   to form urine.                                        presence of urochrome pigment.
                                                        It consists primarily of water (91-96%),
Ureters
                                                         with organic solutes including urea,
  These are a pair of tubes that carry urine            creatinine, uric acid, and trace elements.
   from the kidneys to the urinary bladder.             The pH of human urine ranges from 5.5 to
  They are about 10 to 12 inches long.                  7, averaging around 6.2 and it is acidic in
  Gravity and peristalsis of smooth muscle              nature.
   tissue in the walls of the ureters move              Average urine production in adult humans
   urine toward the urinary bladder.                     is about 1-2 L per day, depending on state
  The ends of the ureters extend slightly into          of hydration, activity level, environmental
   the urinary bladder and are sealed at the             factors, weight, and the individual"s health.
   point of entry to the bladder by the              NERVOUS SYSTEM
   ureterovesical valves.
  These valves prevent urine from flowing              It consists of the brain, spinal cord,
   back towards the kidneys.                             sensory organs, and all of the nerves that
                                                         connect these organs with the rest of the
Urinary bladder                                          body.
  It is a sac-like hollow elastic organ that           Together, these organs are responsible for
   functions as the body’s urine storage tank.           the     control    of    the     body    and
                                                         communication among its parts.
  It is located along the body’s midline at
   the inferior end of the pelvis.                      The brain and spinal cord form the
                                                         control center known as the Central
  The urinary bladder functions as a storage
                                                         Nervous       System       (CNS),      where
   vessel for urine to delay the frequency of
                                                         information is evaluated and decisions
   urination.
                                                         made.
  It is an elastic organs and is able to
                                                        The sensory nerves and sense organs of
   increase     its    volume      greatly   to
                                                         the peripheral nervous system (PNS)
                                                         monitor conditions inside and outside of
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