various parts of reproductive organs& their functions
TRANSCRIPT
Functions: Urination and Copulation
Penis
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Functions: Transport urine & semen
Urethra
Bladder
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Function: Maintain temperature of testes approx. 30 C below normal
body temp.
Scrotum
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Function: Produce sperm and testosterone
Testis
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Function: Produce Sperm
Testis
Seminiferous Tubules
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Testis Cross Section
Interstitial Cells
Produce Testosterone
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Function: Sperm storage and maturation
Epididymis
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Function: Transport sperm to urethra
Vas Deferens
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Function: Produce 60% of alkaline semen including fructose
to provide energy for sperm.
Seminal Vesicles
Ejaculatory Duct
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Function: Produces up to 1/3 of the semen & includes nutrients &
enzymes to activate sperm.
Prostate
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Function: Secretes mucous & alkaline buffers to neutralize acidic
conditions of urethra.
Cowper’s Gland
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Function: Receives penis & semen and serves as birth canal & passage for menstrual flow.
Vaginawww.freelivedoctor.com
Function: Provides passageway for sperm, receives blastocyst, retains & nourishes fetus & expells fetus at term.
Uterus
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Function: Cervical mucosa secretes mucous blocking cervical
canal entrance to uterus.
Cervix
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Function: Uterine lining in which implantation occurs.
Endometrium
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Function: Muscular contractions.
Myometrium
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Function: Passageway for oocyte and site of fertilization.
Uterine Tubes
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Function: Produce oocytes & the hormones estrogen and
progesterone. Ovaries
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Function: Sweep ovarian surface to draw oocyte into ovarian tube.
Fimbriae
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Mechanisms of Hormonal Action
• Direct Gene Activation– lipid soluble, steroid hormones– diffuse through cell membranes– bind to intracellular receptor– activated hormone receptor/complex binds with
gene, turning it on– gene transcribes mRNA– ribosomes use mRNA to synthesize enzymes to
stimulate cell activity or synthesize structural proteins to be excreted or used within the cell
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Direct Gene ActivationSteroid Hormone
Receptor/hormone Complex
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Direct Gene Activation
Receptor/hormone Complex
mRNA
Protein
Aldosterone Cortisol Testosterone Estrogen Progesterone Thyroxine
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Mechanisms of Hormonal Action
• Second Messenger Systems– amino acid & protein based– cannot pass through cell membranes– bind to cell membrane receptors– activate G proteins in membrane to produce
cyclic AMP in cytoplasm– cyclic AMP acts as second messenger inside
cell activating protein kinases– protein kinases trigger cellular responses
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Second Messenger Systems
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Hormone Sources & Functions• Gonadotropin-releasing Hormone
(GnRH) :– Source: Hypothalamus
– Targets & Functions:• Females & Males - Anterior Pituitary
– Stimulates the production of Follicle Stimulating Hormone (FSH) & Leutinizing Hormone (LH)
– Regulates the release of FSH & LH by the anterior pituitary gland
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Hormone Sources & Functions
• Follicle Stimulating Hormone:– Source: Anterior Pituitary
– Targets & Functions:• Females - Ovaries
– Stimulates follicle growth & maturation
– Stimulates estrogen production
• Males - Seminiferous Tubules– Promotes sperm production
(Spermatogenesis) by establishing testosterone receptors on tubules
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Leutenizing Hormone:• Source: Anterior Pituitary
– Targets & Functions:• Females - Ovaries
– Stimulates primary oocyte to complete first meiotic division to become secondary oocyte
– Triggers ovulation of secondary oocyte
– Transforms ruptured follicle into corpus luteum
– Stimulates production of progesterone by corpus luteum
• Males - Seminiferous Tubules– Stimulates sperm production
(Spermatogenesis) by causing interstitial cells in testes to secrete testosterone
Corpus luteum
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Estrogen:• Sources: Maturing Follicles & Corpus Luteum
– Targets & Functions:• Body in general
– Stimulates the development of female secondary sexual characteristics
• Breasts– Stimulates development of milk ducts and
sinuses (ampullae)
• Uterus– Stimulates proliferative phase of uterine
cycle
• Ovaries– Promotes oogenesis
• Anterior Pituitary– Stimulates burst-like release of LHwww.freelivedoctor.com
Progesterone:• Source: Corpus Luteum & Placenta
– Targets & Functions:• Females - Uterus
– Maintains thickened endometrium
– Stimulates nutrient release
– Quiets myometrium
Corpus luteum• Females - Breasts
– Stimulates development of alveoli for milk production
• Females - Anterior Pituitary– Inhibits production & release of FSH &
LHwww.freelivedoctor.com
Testosterone:• Sources: Interstitial Cells in Testes
– Targets & Functions:• Body in general
– Stimulates the development of male secondary sexual characteristics including:
» development of male genitalia
» male skeleton and muscle development
» male patterns for hair growth
» increased RBC production & higher metabolic rate
• Seminiferous tubules– Necessary for the completion of
spermatogenesis
• Anterior Pituitary– Moderate inhibition of pituitary and
hypothalamus www.freelivedoctor.com
Oxytocin:• Sources: Manufactured by hypothalamus. Stored &
released by Posterior Pituitary
– Targets & Functions:• Uterus
– Stimulates contraction of uterine myometrium causing lowering of fetus & labor
• Breasts– Stimulates contraction of milk ducts and
sinuses, releasing milk
Positive Feedback Mechanisms:
1. Childbirth - Stretching of uterus and cervix
2. Suckling - Milk letdown reflex
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Prolactin:
• Source: Anterior Pituitary
– Targets & Functions:• Breasts
– Stimulates alveoli of breasts to produce milk
• Regulation– Release of prolactin by anterior pituitary
is regulated by hypothalamus production of Prolactin Releasing Hormone (PRH) & Prolactin Inhibiting Hormone (PIH)
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Human Chorionic Gonadotropin:
• Source: Trophoblasts of blastocyst & Chorion
– Target & Functions:• Corpus Luteum
– Maintains corpus luteum & causes it to continue producing progesterone in the absence of LH through first four months of pregnancy till placenta produces sufficient estrogen & progesterone to maintain the pregnancy
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Hormonal Regulation of Ovarian & Menstrual Cycles
1. Hypothalamus releases GnRH.
2. GnRH stimulates anterior pituitary to release FSH.
FSH
3. FSH stimulates a follicle to grow & produce estrogen.
Estrogen
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Hormonal Regulation of Menstrual & Ovarian Cycles
FSHEstrogen
4. Rising levels of estrogen cause anterior pituitary to increase production & storage of LH.
LH
Estrogen
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Hormonal Regulation of Menstrual & Ovarian Cycles
5. High estrogen causes LH to be released in a burst & the endometrium to thicken (proliferative phase).
6. High LH stimulates first meiotic division of primary oocyte.
FSHEstrogen
Estrogen
LH
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Hormonal Regulation of Menstrual & Ovarian Cycles
7. High LH triggers ovulation.
FSHEstrogen
Estrogen
LH
8. High LH causes ruptured follicle to become a corpus luteum.
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Hormonal Regulation of Menstrual & Ovarian Cycles
FSH
9. Corpus luteum produces progesterone.
Estrogen
Estrogen
LH
Progesterone
XX
10. Progesterone inhibits the production of FHS & LH by the anterior pituitary & stimulates secretory phase .
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Hormonal Regulation of Ovarian & Menstrual Cycles
11. Diminishing levels of FSH & LH cause corpus luteum to deteriorate & produce less progesterone.
12. Dimishing levels of estrogen & progesterone cause inhibition of FSH & LH to end & thickened endometrium to slough (menses).
Estrogen
FSH
LH
ProgesteroneXX
X
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Hormonal Regulation of Ovarian & Menstrual Cycles
FSH
13. Increasing levels of FSH cause a new cycle to begin.
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Hormonal Regulation in Pregnancy
Normally dimishing levels of estrogen & progesterone from deterioration of the corpus luteum would cause thickened endometrium to slough (menses) which would terminating a pregnancy.
EstrogenProgesteroneX
X
X
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Hormonal Regulation if Pregnancy Occurs
Blastocyst produces human Chorionic Gonadotropin (hCG) hormone which maintains corpus luteum in the absence of FSH & LH for the first trimester.
hCG
Eventually the placenta will produce sufficient estrogen & progesterone to sustain the pregnancy.
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Mitosis
Interphase Prophase Metaphase
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Mitosis
Anaphase Telophase Interphase
• Most cells of the body - growth, replacement, healing.
• No change in the number of chromosomes within each cell.
46
46
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Meiosis
Interphase Prophase Metaphase
46
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Meiosis
Anaphase Telophase Interphase
23
23
Reduction Division
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Meiosis
23
23
23
23
23
23
• Only in gonads.
• Synapsis & shuffling of genetic information providing variation.
• Results in reduction of number of chromosomes by half (haploid).www.freelivedoctor.com
Mitosis/Meiosis Comparison46
46 46
46
23 23
23 23 23 23www.freelivedoctor.com
Gametogenesis:
• Spermatogenesis:– produces male gametes
(sperm)
– occurs in the seminiferous tubules of the testes
– involves meiosis
– occurs throughout life after puberty
– may produce 400,000,000 per day
• Oogenesis:– produces female
gametes (oocytes)
– occurs in the ovaries
– involves meiosis
– occurs after puberty until menopause
– humans normally produce one oocyte during each ovarian cycle
Process through which gametes are formed
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Spermatogenesis
Spermatogonium (46)
Mitosis Daughter Cells (46)
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Spermatogenesis
Spermatogonium (46)
MitosisDaughter Cells (46)
GrowthPrimary Spermatocyte (46)
Meiosis ISecondary Spermatocytes (23)
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Spermatogenesis
Spermatogonium (46)
MitosisDaughter Cells (46)
GrowthPrimary Spermatocyte (46)
Meiosis ISecondary Spermatocytes (23)
Spermatogonium
Meiosis IIEarly Spermatids (23)
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Spermatogenesis
Spermatogonium (46)
MitosisDaughter Cells (46)
GrowthPrimary Spermatocyte (46)
Meiosis ISecondary Spermatocytes (23)
Spermatogonium
Meiosis IIEarly Spermatids (23)
SpermiogenesisLate Spermatids (23)
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Spermatogenesis
Spermatogonium (46)
MitosisDaughter Cells (46)
GrowthPrimary Spermatocyte (46)
Meiosis ISecondary Spermatocytes (23)
Spermatogonium
Meiosis IIEarly Spermatids (23)
SpermiogenesisLate Spermatids (23)
Spermatozoa (23)
(Lumen)
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Oogenesis
Oogonium (46)
Primary Oocyte (46)
(Mitosis)
Primary Oocyte (46)
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Oogenesis
Oogonium (46)(Mitosis)
Secondary Oocyte (23)(Meiosis 1)
OvulationFertilizationPolar Body (23)
(Meiosis 2)
Primary Oocyte (46)
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Definitions & Functions Relative to Reproduction
• Hypothalamus: – Produces GnRH which stimulates the
production of FSH & LH by the anterior pituitary gland initiating the ovarian cycle.
– Produces Oxytocin which is stored in the posterior pituitary gland.
• Posterior Pituitary:– Stores & releases hormone Oxytocin to
stimulate uterine contractions (Braxton Hicks) & the milk let-down reflex.
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Definitions & Functions Relative to Reproduction
• Anterior Pituitary: – Produces hormone FSH which stimulates the
growth & maturation of a follicle, the production of estrogen in females and stimulates sperm production in males.
– Produces & stores hormone LH which causes first meiotic division of primary oocyte, stimulates ovulation, causes the development of and the production of progesterone by the corpus luteum
– Produces & stores hormone Prolactin which promotes lactation .
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Definitions & Functions Relative to Reproduction
• Spermatogonium: – Primordial germ cell in seminiferous tubules
of testes from which sperm are produced.• Oogonium:
– Primordial germ cell in ovaries of fetus from which primary oocytes in follicles are produced.
• Follicle:– Sack-like structure in ovary containing an
oocyte surrounded by one or more layers of cells which produces the hormone estrogen.www.freelivedoctor.com
Definitions & Functions Relative to Reproduction
• Mitosis: – Process through which the nucleus of body cells divide to produce
identical daughter cells for maintenance, healing & growth.
• Meiosis:– Process through which gametes are formed
with half of the normal number of chromosomes for sexual reproduction.
• Ovum:– Functional female gamete which has
completed the first and second meiotic divisions to become haploid.
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Definitions & Functions Relative to Reproduction
• Spermatozoan: – Haploid male gamete which has completed meiosis 1 & 2,
spermiogenesis & is capable of fertilizing a female secondary oocyte.
• Fertilization:– Process through which haploid male &
female gametes fuse to form a diploid zygote.
• Polar Bodies:– Nonfunctional haploid female cells with little
to no cytoplasm produced in meiosis.www.freelivedoctor.com
Definitions & Functions Relative to Reproduction
• Hormone: – Chemical messenger which is used to regulate
reproductive cycles and activities.
• Semen:– Mixture of sperm and fluids from male
reproductive glands which supplies energy, neutralizes acidic conditions in the reproductive tracts and activates sperm.
• Hyaluronidase:– Enzyme in acrosome of sperm that enables
sperm nucleus to enter the female gamete.www.freelivedoctor.com
Bone Formation
Preembryonic Development
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Definitions & Functions
• Zygote:– A fertilized ovum which is diploid.
• Cleavage Divisions:– Mitotic divisions of the zygote to increase the
number and surface area of cells in a preembryo (2 cell, 4 cell, 8 cell, etc.)
• Morula:– A berry shaped cluster of preembryonic cells
produced from cleavage divisions .www.freelivedoctor.com
Definitions & Functions• Blastocyst:
– A fluid filled sphere of cells formed from the morula which implants in the endometrium.
• Trophoblast:– One of the cells making up the outer wall
of the blastocyst which will form the chorion.
• Inner Cell Mass:– A group of cells inside of the blastocyst
from which the three primary germ layers will develop.
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Definitions & Functions• Chorionic Villi:
– Finger-like growths of the trophoblasts into the endometrium to form the placenta.
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Definitions & Functions• Chorion:
– Outermost embryonic membrane which forms the placenta & produces human chorionic gonadotropin.
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Definitions & Functions• Amnion:
– Membrane which surrounds embryo to form the amniotic cavity & produces amniotic fluid.
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Definitions & Functions• Amnionic Fluid:
– Protects fetus from trauma & permits free movement without adhesion.
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Definitions & Functions• Yolk Sack:
– Provides initial nutrients, supplies earliest RBCs and seeds the gonads with primordial germ cells.
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Gastrulation
• Preembryo becomes embryo as three primary germ layers form.
Prembryo Embryo
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Ectoderm Derivatives
• Brain, spinal cord, nerves
• Cornea & lens of eyes
• Outer skin & accessory structures– hair– nails
• Enamel of teeth
• Linings of nasal & oral cavities & anal canal
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Endoderm Derivatives
• Epithelial lining of digestive tract
• Liver and pancreas
• Epithelial lining of respiratory tract & tonsils
• Epithelial lining of reproductive ducts & glands
• Thyroid, parathyroid & thymus glands
• Epithelial lining of bladder & urethrawww.freelivedoctor.com
Mesoderm Derivatives• Muscle: skeletal, cardiac & smooth
• Connective tissues: cartilage, bone, adipose
• Bone marrow, blood & lymphatic tissues
• Endothelial linings of blood & lymphatic vessels
• Visceral peritoneum of organs in ventral cavity
• Fibrous & vascular tunics of eyes
• Organs of urogenital system: kidneys, gonads & reproductive ductswww.freelivedoctor.com
Placental Function
O2Glucose VitaminsMinerals
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Placental Function
Alcohol
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Fetal Alcohol Syndrome
• Prenatal & postnatal growth retardation
• CNS involvement:– neurological abnormalities– developmental delays
• Alcohol related birth defects
• Mental retardation
• Speech & hearing impairment
• Learning, attention & memory deficitswww.freelivedoctor.com
Placental Function
CO2WastesUrea
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Placental Function - Smoking
CO2
O2
CO
Nicotine
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Smoking During Pregnancy• Increases risk of ectopic pregnancy
• Doubles risk of placenta previa & abruptio placenta
• Slows fetal development
• Doubles risk of low birthweight babies
• Increases risk of preterm deliveries
• Increases risk of cleft palate & lip
• Doubles risk of sudden infant death syndrome (SIDS)
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Drug Use
Antibiotics Nicotine
Crackwww.freelivedoctor.com
Irradiation• High-energy
– X-rays– Gamma rays
• Penetrate deeply into tissues causing ionization of molecules.
• May directly or indirectly affect the genetic material resulting in point mutations (affecting a single base).
• May break chromosomes causing deletions or translocation of genetic information.
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Placenta abruptio
• Any amount of placental separation prior to delivery.
• Causes & Risk Factors:– Abdominal trauma– Hypertension during pregnancy– Diabetes mellitus – Cigarette smoking– Alcohol use during pregnancy
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Placenta previa
• Placental growth across or adjacent to opening of cervical canal in the uterus.
• Risk Factors:– The number of prior pregnancies– Multiple pregnancies (twins/triplets)– Prior C-section where scar is close to cervix
• Symptoms:– Spotting during 1st & 2nd trimesters– Sudden, painless & profuse vaginal bleeding
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Ectopic Pregnancy• Implantation of blastocyst anywhere other than
within the uterus.• Causes & Risk Factors:
– Physical blockage of uterine tube.– Scarring of uterine tube by prior tubal
infection (pelvic inflamatory disease).– Pregnancy following tubal ligation reversal
or despite oral contraceptive use.• Symptoms:
– Lower abdominal or pelvic pain.– Mild cramping on one side of pelvis.– Abnormal vaginal bleeding (spotting).www.freelivedoctor.com
Gonorrhea• Bacterial Pathogen: Neisseria gonorrhoeae
• Transmission: Sexual contact with infected person or contact with bacteria in the birth canal of an infected mother.www.freelivedoctor.com
Gonorrhea• Pathology: Inflammation of skin & mucous membranes of
urinary & reproductive organs.
• Females: Painful urination, abdominal pain, pelvic inflammatory disease, & sterility.
• Males: Painful urination with purulent discharge & possible sterility.www.freelivedoctor.com
Gonorrhea• Babies: Contract bacteria in birth canal of infected mother.
• Congenital Effects: Conjunctivitis & blindness.
• Treatment: Ceftriaxone & Tetracycline– Silver Nitrate in eyes of infantswww.freelivedoctor.com
Syphilis• Bacterial Pathogen: Treponema pallidum
• Transmission: Sexual & transplacental contact. www.freelivedoctor.com
Primary Syphilis• Incubation period - 21 days (average)
• Painless chancre (lesion) where bacteria enter mucous membranes or skin.
• Spontaneously heals after 3 to 8 weeks.www.freelivedoctor.com
Secondary Syphilis• Fever, influenza-like symptoms, swollen lymph nodes & skin rash.
• Without treatment, these symptoms may last several weeks & disappear or death may occur.www.freelivedoctor.com
Tertiary Syphilis• Involvement of the skin, cardiovascular and nervous systems.
• Gummas develop in infected tissues.
• Treatment of Choice: Penicillin.www.freelivedoctor.com
Congenital Syphilis• Transplacental transmission.
• Stillborn, infective skin lesions, deafness, impaired vision, Hutchison’s teeth, & skeletal deformities . www.freelivedoctor.com
Chlamydia• Most prevalent STD in US.• Bacterial Pathogen: Chlamydia trachomatis
• Pathology: Nongonococcal urethritis resulting in serious reproductive tract complications (up to 80% asymptomatic)– pelvic inflamatory disease– infertility– ectopic pregnancy
• Babies infected in birth canal– chlamydial opthalmia & pneumonia
• Treatment: Tetracyclinewww.freelivedoctor.com
Genital Herpes• Pathogen: Herpes Simplex Virus - Type 2
• Transmission by secretions from lesions.
• Crops of vesicular lesions occur on & around genitalia.
• Lesions are recurrent (as often as 4 weeks) & lead to painful ulcerations.
• Associated with higher than normal cervical cancer with a 50% mortality rate in infected women.
• Transplacental transmission to fetus.
• Treatment: Acyclovire to reduce symptoms.www.freelivedoctor.com