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					     Chapter 20:
Urogenital and Sexually
 Transmitted Diseases
Components and Functions of the Urinary System
•The urinary system consists of paired kidneys
and ureters, the urinary bladder, and the urethra
•Each day the kidneys filter 200 L of fluid from
bloodstream
   •Allows wastes and excess ions to leave in urine and returns
   needed substances to bloodstream
   •Regulate the blood volume and chemical make-up
   •Metabolize vitamin D
   •Act as endocrine gland
      •Produce renin- functions in blood pressure regulation
      •Produce erythropoietin – stimulates RBC formation
Urinary System Structures
Structures of the Kidney
      Nephron – functional unit of kidney
• Each kidney contains over 1 million nephrons
  and thousands of collecting ducts
• Each nephron consists of:
  – Glomerulus – tuft of capillaries encircled by capsule
  – Proximal convoluted tubule – drains filtrate from
    renal corpuscle
  – Loop of Henle – has descending and ascending arm
     • Dips down deep into medulla region
  – Distal convoluted tubule – empties into collecting
    duct which deliver urine to the minor calyces
                  Flow of Urine Out of a System

•In a nephron, the fluid portion of the blood is filtered from the
glomerulus, a coiled cluster of capillaries, to the kidney tubules


•Beginning with the renal cortex, nephrons remove solutes and
water from the blood.


•As these materials pass through the renal medulla; water, salts,
and sugars pass back into the blood.
• Urine, the wastes remaining in the kidney tubules, pass
  through collecting ducts to the ureter of each kidney

• The ureters carry the urine, which is normally free of
  microbes, to the urinary bladder, where it is stored until
  released through the urethra during micturition
  (urination)
Flow of Urine Out of a System
Urinalysis can reveal pH or water concentration imbalances, the
presence of glucose or proteins and other conditions associated
with infections, metabolic disorders, and other diseases
                 The Female Reproductive System
•The female reproductive system consists of the ovaries, uterine tubes, uterus,
vagina, and external genitalia


•The paired ovaries contain cellular aggregations called ovarian follicles, each
containing an ovum (plural: ova), or egg, and surrounding epithelial tissue.


•During a woman’s reproductive years, an ovum capable of being fertilized is
released once each month.


•The uterine tubes receive ova and convey them to the uterus.


•Fertilization usually occurs in the uterine tubes.


•The uterus is a pear-shaped organ in which a fertilized ovum develops.
•It is lined with a mucous membrane called the endometrium, the
outer portion of which is sloughed during menstruation.


•The vagina, also lined with mucous membrane, extends from the
cervix (an opening at the narrow, lower portion of the uterus) to
the outside of the body.


• It allows passage of menstrual flow, receives sperm during
intercourse, and forms part of the birth canal.
• The female external genitalia include the sexually
  sensitive clitoris, two pairs of labia (skin folds), and the
  mucous-secreting Bartholin glands.

• Because they nourish offspring, mammary glands
  (breasts) are considered part of the female reproductive
  system.

• These modified sweat glands develop at puberty and
  contain gland cells, embedded in fat, that produce milk
  and ducts that carry the milk to the nipple.
Female Reproductive System
            The Male Reproductive System

•The male reproductive system consists of the testes,
ducts, specific glands, and the penis


•The testes secrete the hormone testosterone into the
bloodstream and produce sperm, which are conveyed
through a series of ducts to the urethra


•Secretions from seminal vesicles, bulbourethral glands
and the prostate gland mix with sperm to form semen
Male Reproductive System
       Bacterial Urogenital Diseases
• Urinary Tract Infections (UTI’s) are among
  the most common infections
  – 2nd to respiratory infections
• Major cause is failure to completely empty
  bladder – retained urine serves as a reservoir
   – May result from age, pregnancy, enlarged
     prostate, paralysis
• Females are more susceptible due to shorter
  urethra and close proximity to anus
• Escherichia coli: - causative agent in 80%
• About 50 % of nosocomial infections are UTIs
•   Pyelonephritis – inflammation of kidneys
•   Urethritis: inflammation of the urethra
•   Cystitis: inflammation of the bladder
•   Dysuria: pain and burning upon urination
•   Manifestations:
    – L-UTIs: dysuria, increased frequency, urgency,
      suprapubic pain, bacteriuria, and pyuria
    – U-UTIs: back pain, chills, and fever, in addition to L-
      UTI symptoms
• Diagnosed by microbes in urine
• Treated with antibiotics
    – Amoxicillin, quinolones, sulfa drugs
      Glomerulonephritis – Bright’s Disease


•Autoimmune condition following strep throat caused by
strains of S. pyogenes have cell wall components similar to
glomerular tissues

•Antibiodies can’t distinguish between pathogen and kidney
tissues so they build up and damage the glomeruli resulting in
an inflammatory response

•Blood and proteins leak into urine, May cause permanent
kidney damage but most people recover in 3-12 months
                          Leptospirosis
•Caused by the spirochete Leptospira interrogans; a zoonosis
usually acquired by humans through contact with contaminated
urine, directly or in water or soil


•An infectious disease that affects the liver and kidneys in
humans and some animals


•The bacteria live within the convoluted tubules of the kidney
and shed into the urine


•In some parts of the world, more than 50% of the rats are
carriers of Leptospira
– Diagnosed by direct microscopic examination

– Responds to almost any antibiotic but only for the 1st 3
  days

– Weil’s syndrome is an especially virulent form of the
  disease resulting in significant liver damage

– May be prevented by pet vaccines and avoiding
  contaminated water
 A colorized TEM of
Leptospira interrogans
                      Bacterial Vaginitis


•Vaginitis usually is caused by opportunistic organisms that
multiply when the normal vaginal microflora are disturbed by
antibiotics or other factors


•Several organisms account for a share each of vaginitis cases or at
least serve as a marker for disruption of the vaginal flora.


•The bacterium Gardnerella vaginalis, in combination with
anaerobic bacteria, accounts for about one-third of the cases
– When pH is high (5-6) G. Vaginalis reacts with
  anaerobes causing disease

– Diagnosis is made from wet mounts of discharge that
  display ―clue cells‖and absence of lactobacilli

– Treatment with metronidazole (Flagyl) suppresses
  anaerobes but allows lactobacilli to repopulate

– Tetracycline and ampicillin are alternative treatments

– Live-culture yogurt douche will replace Lactobacilli
Normal Vaginal Epithelial Cells
•A ―clue cell‖ of Gardnerella infection in a vaginal smear
•Thick layer of bacteria can be seen clinging to the surface of the
clue cell
           Other Causes of Vaginitis

• Trichomonas vaginalis
  – opportunistic protozoan usually transmitted sexually
  – Treated with metronidazole (Flagyl)


• Candida yeast
  – characterized by scanty, thick, curd-like discharge
  – Treated with Nystatin or Imidazole
  – Main ingredients in over the counter treatments
           Toxic shock syndrome (TSS)
• Caused by strains of Staphylococcus aureus capable of
  producing exotoxin C
• Associated with the use of tampons especially when
  they are not replaced often
• Males with boils or other staph infections are
  susceptible
• Clinical manifestations include fever, drop in blood
  pressure, and rash
• Mortality rate:2-5%
  – Less than 30 US cases reported each year
  – Recurrence is a frequent possibility
     • May treat prophylactically with antibiotics
             Parasitic Urogenital Diseases



•Transmitted primarily by sexual intercourse
•May also be transmitted through contaminated toilet
seats and linens (usually in children)

•At least three species of protozoa of the genus
Trichomonas can parasitize humans, but only T.
vaginalis causes trichomoniasis
                 Trichomonas vaginalis
•T. vaginalis is a large flagellate with four anterior
flagella and an undulating membrane


•Infects urogenital tract surfaces in both genders and
feeds on bacterial and cell secretions


•5.5 to 6.0 is optimum pH for the organism


•Symptoms include intense itching and a copious white
discharge, the consistency of raw egg white
                    Trichomoniasis

•Diagnosis of trichomoniasis is by microscopic
examination of vaginal or urethral smears and
treatment includes application of metronidazole
(Flagyl), which restores normal vaginal pH in women


•Flagyl cannot be used during pregnancy because it
causes abortions, but it is important to eliminate the
infection before delivery to prevent infecting the infant


•A vinegar douche usually is effective
Trichomonas vaginalis (534X)
  Bacterial Sexually Transmitted Diseases--Gonorrhea


•Gram-negative, spherical or oval diplococcus with
flattened adjacent sides resembles a pair of coffee beans
facing each other


•Virulence factors:
   •Attachment pili- attach to cells of urinary tract and
   to sperm
   •Endotoxin – damages fallopian tubes
   •Extracellular protease – destroys IgA antibodies
   •Capsule which allows evasion of phagocytosis
G-, spherical or oval diplococci
   Symptoms of
Gonorrhea--Urethral
 Drip of Pus in Men
Symptoms of Gonorrhea—Gonococcally Caused Arthritis
• May remain asymptomatic but carriers for up
  to 15 years
• Diagnosed by inspecting genitals and culturing
  discharge
• Treatment
  – Sulfa drugs, penicillin, doxycycline (also kills
    Chlamydia)
  – No vaccine available