Female Reproductive System 2 Flashcards
Describe the myometrium, after parturition vs during pregnancy
Interlacing bands of smooth muscle fibers
• Three poorly defined layers
• Functional syncytium – contract under the influence of oxytocin at parturition
During pregnancy
• Smooth muscle hypertrophy (x10) and hyperplasia
• Increase in collagen fibers
• Uterine walls thin – stretch
After parturition • Some muscle fibers degenerate; uterus returns to near original size • Collagen degraded by enzymes • Myometrium slightly thicker • Uterine cavity larger than before
What is uterine Leiomyoma/fibroid?
• Smooth muscular fibers arranged in whorls • Fibrous stroma • Well defined margin • Types: - Submucosal - Intramural - Subserous - Pedunculated
What are the uterine changes related to implantation ?
• Implantation window 6th – 10th day after ovulation
• Embryo releases human chorionic gonadotropic hormone (hCG)
- Maintains corpus luteum
Continued progesterone secretion
• Endometrium
- Endometrial (decidual) cells
Large, round, pale, glycogen rich cytoplasm
- Glands
More dilated and coiled in
early pregnancy
Later: thin and flattened
Explain the structure and function of placenta
• Temporary organ of pregnancycontains both fetal and maternal tissue
• Function:maintaindevelopingfetus
o Secrete hormones: e.g., hCG, hPL, progesterone, relaxin, leptin
o Growth factors:
Insulin like growth factor I &II
Epithelial growth factor
o Site of Exchange: gases, metabolites, nutrients & waste
• Structure
Fetal side:
Chorion
Smooth and shiny (amnion – innermost membrane)
Maternal side:
Decidua basalis—>(basal plate) modified endometrium over implantation site
Fleshy looking
15-25 cotyledons—>bulges counted after parturition
What are the parts of the placenta?
Chorion: derived from trophoblast layers and extraembryonic mesenchyme
• Trophoblast
o Internal layer—>Cytotrophoblast
Mitotically active
o External layer—>Syncytiotrophoblast (secretes hormones, e.g., hCG)
Basophilic multinucleate cytoplasmic mass
Erosive: converts endometrium to decidua
• Proliferation of chorionchorionic villi
o Primary, Secondary, Tertiary
o Anchoring villi: extend into decidua basalis
o Floating villi: free in intervillous space, bathed with maternal blood
o Intervillous space: maternal blood
What is the primary chorionic villi?
- Primary chorionic villi: ― Day 11-13
― Finger-like extensions in maternal decidua
― Cytotrophoblast penetrate blood filled
spaces of syncytiotrophoblast
What is the secondary chorionic villi?
2. Secondary chorionic villi ― ~ Day 16 ― Primary villi invaded by loose CT from extraembryonic mesoderm E.g., fibroblasts, phagocytic cells (Hofbauer) ― Inner layer of cytotrophoblast ― Outer layer of syncytiotrophoblast
What is the Tertiary villi?
3. Tertiary villi ― Form by end of week 3 ― Smaller profiles in cross sections ― Blood vessels develop in extraembryonic mesoderm Umbilical vessel branches ― Outer syncytiotrophoblast layer
Early Pregnancy • Large edematous villi • Few blood vessels • Many CT cells • Continuous cytotrophoblast layer • Thick syncytiotrophoblast
Late Pregnancy
• More fetal blood vessels
• Less cells, placental macrophages
• Cytotrophoblast appears discontinuous
• Aggregates of syncytiotrophoblast nuclei: Syncytial
knots
What are the components of the placenta?
Exchange occurs through the placental barrier • Components (thinnest portion): ― ME: Maternal RBC in IV space ― Syn: Syncytiotrophoblast N: cell nucleus ― Thin cytotrophoblast layer ― TBL: Basal lamina of trophoblast ― CT: Mesenchyme connective tissue
― EBL: Basal lamina of umbilical vessel
― FEn: Umbilical endothelium
― FE: Fetal erythrocyte Which villus?
• Thins out at ~4th month - excha
Describe the structure function of the cervix
Connects uterine and vaginal cavities.
• Functions:
o Permits/restrict passage of spermatozoa
o Allows passage of fetus at parturition
o Protects upper genital tract from bacterial infection
• Regions:
1. Cervical canal (Endocervix)
− Internal os: communicates with uterine cavity
2. Ectocervix: projects into vaginal cavity
− External os: communicates with vagina
3. Transformational Zone (TZ)
Describe the basic histology of the cervix
Basic histology
o Mucosa: varies from simple columnar to stratified
squamous epithelium
o Dense fibrous connective tissue wall with some smooth muscle
Lysis causes softening of cervix at parturition
What is the cervical canal/endocervix(CC)?
− Mucosa varies from other parts of the uterus
Large, simple branched tubular glands (Gl)
No spiral arteries
Little/no variation in thickness during cycle
Not shedding in menses
What are the components of the cervix?
• Simple columnar epithelium (SCE)
o Invaginates to form mucus secreting cervical glands
-Glandular secretions undergo cyclic changes in the menstrual cycle
1. Midcycle Ovarian activity?
― 10x increase in mucus production
― Thin, watery to allow sperm passage
2. Other times: viscus plug—>protective
What is the ectocervix like?
― Stratified squamous epithelium (SSEp) as
in the vagina or vulva. Why?
― Cells have large glycogen storespale
staining
― No glands
― Epithelial cells constantly shed into vagina
Describe the transformation zone of the cervix (T zone)?
Transformation zone (T zone)
― Junction between ectocervix and cervical
canal
Reproductive years: just outside external os
Prepubertal + Postmenopausal: cervical canal
― Abrupt change from endocervical to ectocervical mucosa
Squamocolumnar junction
Describe the pathology of the cervix
Mucosal Glands
• Openings can become occluded
o Retention of mucus secretions - dilated
o Formation of Nabothian cysts
Epithelial Cells
• Transitional Zone*
o Cervical stroma hormone sensitive
Estrogen—>expansion—>Ectropion
Metaplasia (normal - reproductive age)
Columnar—>Stratified squamous
o Chronic/persistent cervical infection—>
metaplasia
o Development site of precancerous lesions
o Cervical cytology used as screen for lesions
How is human papilloma virus relevant to cervical pathology?
• Low risk HPV
o Affect mature cells
o Genital warts and mild cervical dysplasia
• High risk (Types 16 &18*)
o Affect stem cells
o Severe dysplasiacancer: cervix, vagina, vulva, anus, penis
• Infection:
o Most self resolving
o 5-10% persist (viral DNA integrates into stem cells)
o Dysplasia 20-30 years later
HPV affects…
Stratified squamous epithelium
How can we screen for cervical pathology?
• Direct visualization – speculum exam, colposcopy
• Cytology – Papanicolaou (Pap) Test
o Scarpe surface cells: brush, spatula
o Cervicitis, dysplasia, cervical carcinoma o HPV DNA testing
What are the layers of the vagina?
Fibromuscular canal organized in 3 layers:
1. Mucosal layer:
―Transverse folds or rugae
― Non keratinized stratified squamous epithelium ―Lamina propria:
Superficial: Loose connective tissue papillae
Deep: Fibrous CT, elastic fibers, thin-walled veins. *
No glands (lubrication: cervical and vestibular glands)
- Smooth muscle layer: 2 indistinct layers ―Inner circular
― Outer longitudinal: continuous with longitudinal layer of uterus ―Some Striated muscle fibers may be present
3. Adventitial layer: ―Inner Dense connective tissue Elastic fibers ―Outer loose connective tissue Neurovasculature
What are the clinical correlations of the vagina?
Vaginal mucosa undergoes cyclic changes during the menstrual cycle
• Follicular phaseepithelial cells produce and store glycogen.
o Which hormone? Endometrial activity?
• Desquamation of cells releases glycogen into lumen
• Glycogen converted to lactic acid by lactobacillus acidophilus o Bacteria - normal flora
o Make vaginal fluid pH more acidic (~4)
o More acidic near midcycle
• Clinical correlate : Acidic pH prevents infection
o Yeast overgrowth post antibiotics, other infectionsvulvovaginitis
• Empty looking apical cellsglycogen extraction in tissue processing
Describe the structure of the mammary glands
Modifiedapocrinesweatglands • Glandular elements arranged radially around the nipple—>irregular lobes o 15-25 lobes per breast Subdivided into lobules
• Duct: Compound – drains lobules
o Epithelium varies:
Stratified squamous keratinized–simple cuboidal
o Terminates in Lactiferous duct
Forms lactiferous sinus just before nipple
• Secretoryunit(lobules):Tubuloalveolar
• Suspensory/ Cooper’s ligament – fibrous bands
(connect with dermis)
• Histology varies with sex, age and physiological state
What are the main cells in the mammary glands?
1. Glandular Epithelial Cells ―Secretory cells in acinar glands (active lactating glands) ―Prolactin induces secretion of milk Lipids: Apocrine secretion Proteins: Merocrine secretion Antibodies (IgA) From which cells?
- Myoepithelial cells (MEp)
―*Secretory portions, large ducts
―Between epithelial cell and basal lamina
―Contract under oxytocin (suckling)
Force milk from the alveoli into the duct system —>ejection
Describe the ductules of the mammary glands
- Lactiferous ducts drain lobules
- Lobule = Terminal duct lobular unit (TDLU)
- Secretory unit
I. Inactive: terminal ductules
II. Active: alevoli/ acini - Intralobular collecting duct
- Intralobular stroma
― Loose connective tissue ― Hormone sensitive
• Interlobular dense connective tissue o Abundant adipose tissue
• Cells:
o Line secretory and ductal portions
o Glandular Epithelial cells
Inner: face luminal surface
o Myoepithelial cells
Outer: toward basal surface
What are the hormonal functions of the mammary gland?
• Puberty
o Estrogen & Progesterone Source?
Development of mesenchymal cells
Interlobular adiposeBreast enlargement
Ducts extend, branch into developing stroma
• Pregnancy o Glands complete maturation o Estrogen & Progesterone Sources? Massive TDLU increase High progesterone: inhibit milk production o Other hormones: prolactin, hPL
• Lactation o Estrogen and progesterone Why? o Prolactin (?? pituitary) Induce milk secretion after birth o Oxytocin (?? pituitary) Stimulate milk ejection
Describe the inactive mammary gland in prepuberty
- Presence of lobes and lobules
- Not well developed
- Stroma»_space;> glands
- Mostly ductal elements
- Prepubertal —> Few adipocytes
- After puberty—>Increased adipocytes
- Postmenopausal—>general atrophy, (only ducts – male breast)
Describe the inactive mammary gland after puberty
• Complete ductal architecture by adulthood
• Stroma»_space; glands
• Ducts: simple cuboidal epithelium
o Cell height varies throughout menstrual cycle
- Follicular phase (lactiferous ducts) Hormone?
― Terminal ductules (TD): cords, cuboidal cells, narrow lumen ― Stroma: Less dense - Luteal phase (alveoli) Hormone?
― TD: cell height, lumen present, some secretions ― Stroma: fluid accumulates (some edema)
― Abrupt Involution + apoptosis leading up to menses
Describe the active mammary gland in the proliferative stage
• Estrogen, progesterone, human placental lactogen (hPL): o First Trimester: cell proliferation
o Second Trimester: non-uniform development o Third Trimester: ducts + glands well developed
• Secretory Unit
- TD: elongate and branch
- TD: differentiate into alveoli (breast enlargement)
- Alveoli: maturation begins
• Epithelial Cells:
1. (All): Proliferate and differentiate
2. (Glandular): vary in shape: flat – low columnar
3. (Glandular): cuboidal, basal nuclei, around central lumen
― Secretory vesicles, lipid droplets (Breast enlargement)
• Stroma:
- 2nd Trim: Plasma cell (IgA), lymphocyte, eosinophil infiltration
- 3rd Trim: Proliferation declines (decreased CT & adipose)
Describe the active mammary gland in the lactating stage
• Mostly glandular tissue»_space; Stroma
• Alveoli:
o Well developed
o Prominent lumen with Secretions
• Epithelial cells (Alveoli):
o Apical cytoplasm: Large lipid droplets, secretory vesicles o Actively secrete lipids and milk proteins
• Lobular stroma
o Infiltrated by plasma cells (arrows)
o Decrease in adipose and connective tissue
• Large lactiferous(excretory)ducts
• Cessation: gland atrophy, regression to inactive state
What is the clinical significance of breast cancer?
Most common cancer in women (U.S.)
Most common type is ductal
Malignant cells proliferate
o Can breach BM, invade stroma
Loss of normal tissue architecture
Cell morphology depends on Grade
o Low (~normal)/ High (pleomorphic)
Necrosis, abnormal Calcifications
Nipple retraction: Cooper’s ligam
