| Urogenital and Sexually Transmitted Diseases |
Urogenital and
Sexually Transmitted Diseases
- The four major components of the urinary
system are the kidney, ureter, bladder, and
urethra.
- Two kidneys form the urine. Two ureters
conduct the urine from the kidneys to one
bladder. The one bladder stores the urine,
and finally the one urethra conducts the
urine from the bladder to outside of the
body.
- The capsule is a tough layer of
connective tissue surrounding the kidney.
The renal arteries and veins supply and
drain blood from the kidney respectively.
The urine is produced in the cortex,
medulla, renal column, and pyramid. The
urine is collected by papillae and directed
to the minor calyx then to the major calyx
then to the renal pelvis and finally to the
ureter. The ureter drains the urine to the
bladder where it is stored.
- The nephron is the functional unit of
the Kidney that produces urine is, It is a
complex structure composed of several
discrete parts. Blood enters and leaves via
the renal artery and renal vein. Within the
Glomerular capsule the cellular portions of
the blood are separated from the
non-cellular portions of the body. The
non-cellular portions enter the loops of
Henle. Within the loops all non-waste
components are returned to the blood stream,
and the waste continues on to the collecting
duct. Within the collecting duct, final
adjustments are made to the urine before it
enters the ureter for its trip to the
bladder where it will stored. In addition
to the removal of waste from the blood, the
nephrons also help to regulate the blood
pressure and ion concentrations within the
blood.
- Urine flows down the ureter, through the
ureteral opening and into the bladder where
it is stored until about 300 ml is
accumulated. Upon urination, the
sphincters are relaxed and the detrusor
muscle contracts to expel the urine through
the internal urethral orifice, through the
prostate gland, through the external
urethral orifice and ultimately out of the
penile urethra. Of course, on males there
is a prostate gland, which is absent in
females. Trouble with the prostate gland
often involves swelling near the internal
urethral orifice that cause small amounts of
urine to be retained within the bladder and
localized around the internal orifice. This
retained urine causes inflammation that
leads to the continued retention of more
urine around the internal orifice.
- Not all of the urinary tract is sterile;
the urethra has a normal complement of
bacteria. The normal microbiota prevent the
colonization by harmful organisms.
- UTI occur when microbes colonize regions
of the urinary tract that are normally
sterile. Depending on the extent of the
infection, this can be very serious.
- The body tries to flush the infection
out by frequent urination, but of course
the microbes are expecting this and have
developed defense mechanisms to counter the
attach. Sometimes these defenses include
the creation of biofilms.
- The vagina leads to the cervix. The
cervix leads to the uterus from below while
the uterine tubes (fallopian tubes) connect
to the uterus from above. It is important
to note that at times other than ovulation,
the vagina has an acidic pH created by
resident lactobacilli that feed on glycogen
secreted by the walls of the vagina. At
times other than ovulation, the cervix is
occluded by a plug of mucus. During
ovulation, the cells around the cervix,
change the ratio of water and mucus thereby
making the plug disappear to allow sperm to
enter the uterus and ultimately the
fallopian tubes.
- The cervix is the site of cervical
cancer and fortunately can be reached by
route of the vagina, thereby making it
possible to test for metastasis with a pap
smear.
- The fallopian tubes are NOT connected to
the ovaries but rather are open to the body
cavity above it.
- It is therefore possible for a bacteria
to enter abdomen cavity via the vagina.
- This is also the path for ectopic
pregnancy
- Several STI (Sexually Transmitted
Diseases), viral, bacterial, protozoa are
routes of infection are described.
- Nonvenereal diseases of the reproductive
system including Toxic Shock Syndrome and
Candidiasis.
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