Female Reproductive: Accessory Organs

  1. Isthmus
    • has a much more simple mucosa than the ampulla (no fern leaf appearance)
    • wall is quite thick - still has the same layers, but muscle layer is much thicker than in amulla
    • Image Upload 1
  2. Uterus
    • large structure with 3 layers:
    • 1. perimetrium (outermost made up of a mesothelium & underlying elastic tissue)
    • 2. myometrium (thickest part)
    • 3. endometrium (lines the lumen)
  3. Myometrium
    • all smooth muscle
    • cells change during pregnancy
    • a typical smooth muscle might be ~50 microns in length; during pregnancy these cells can get to be 50x bigger
    • enlargement of uterus during pregnancy is both hypertrophy (enlargement) & hyperplasia (↑ #) of myometrium cells
    • cells are oriented longitudinally
  4. What lies between the outer & inner layer of smooth muscle cells?
    • stratum vasculare
    • Image Upload 2
    • aka blood & lymphatic vessels
    • from BVs there are branches that go toward the endometrium & give rise to the Spiral Arteries
  5. What is the lowest/most inferior aspect of the uterus?
    • the cervix
    • it’s continuous with the uterus
    • has 2 openings: internal os & external os (faces the upper part of the vagina)
  6. Endometrium
    • thickness varies depending on cycle stage (1-6mm)
    • consists of a stratum functionale & stratum basale
    • a number of glands grow down from the endometrium surface & puncture both layers
    • BVs from the myometrium extend up into branches that become spiral → straight arteries in the endometrium
    • Image Upload 3
  7. What is lost during menstruation?
    • the stratum functionale, which is endometrial layer closest to the uterine lumen
    • it’s lost at the end of each menstrual cycle
    • the stratum basale persists/isn’t lost during menstruation
    • it’s the glands/BVs in the stratum basale that allow for regrowth & repopulation of the stratum functionale after menstruation
  8. Proliferative/Estrogenic Stratum Functionale Stage
    • happens as ovarian follicles grow because as granulosa cells proliferate & grow, they produce estrogen 
    • stromal, endothelial & epithelial    proliferation
    • epithelial migration covers denuded surface (following menstration)
    • spiral arteries lengthen
    • glands grow but at this stage are non-secretory
    • collagen & ground substance are deposited
    • this whole process lasts for ~2 weeks, until 1 day post ovulation
    • Image Upload 4
  9. Secretory (Progestational) Stratum Functionale Stage
    • post-ovulatory progesterone being made from the Corpus Luteum causes the glands to enlarge & become sacculated
    • glands also fill with secretory products (glycogen)  
    • there's lengthening & coiling of the spiral arteries
    • get lots of edema
    • white spaces represent a hydrated stroma
    • entire endometrium at this point has gotten much thicker, there's been increased proliferation of glands & BVs, & fluid has deposited between stromal cells
    • the secretory phase continues for ~10 days if no pregnancy occurs
    • Image Upload 5
  10. Menstrual (Ischemic) Stratum Functionale Stage
    • if no pregnancy occurs & the corpus luteum collapses, loss of progesterone (+ other CL hormones) causes periodic spiral artery contractions (lasting hours)
    • the stratum functionale becomes ischemic (because it no longer has a blood supply)
    • dead tissue & blood are lost during menstruation (~5 days, 35-50ml blood loss)
    • blood flow to straight arteries in stratum basale is maintained
    • it's the surviving glandular cells that re-populate the endometrium surface (stratum functionale)
    • Image Upload 6
  11. Menstrual Cycle Overview
    1. Menstrual Phase: days 1-5

    • 2. Follicular/Proliferative Phase: days 5-14
    • secretion of FSH causes Estrogen levels to rise, which helps ovarian follicle maturation (& stimulates the re-growth of the uterine endometrium functional layer)
    • the end of the follicular phase = LH surge (after enough FSH has been made)
    • LH is required for ovulation (including that last bit of follicle maturation)
    • ovulation usually occurs 12-18 hours after LH surge

    • 3. Luteal/Secretory Phase: days 14-27
    • estrogen levels peak then drop (not all the way though)
    • progesterone levels are rising & high
    • if no fertilization occurs, corpus luteum degenerates, estrogen & progesterone levels fall, & the secretory endometrium enters the ischemic phase

    • 4. Ischemic Phase: days 27-28
    • progesterone & estrogen levels fall rapidly & the functional endometrium becomes ischemic
  12. Uterine Cervix
    • is just inferior to the main body of the uterus 
    • is an area that has large, highly branched glands that have a simple columnar epithelium 
    • there aren't many morphological changes in the cervix (unlike in the uterus) during the menstrual cycle, however there are glandular changes
    • Image Upload 7
  13. Cervical Glandular Changes
    • as ovulation approaches, mucus production from glands increases 10x
    • during that time the gland product becomes less viscous (is more watery) than at other times of the cycle
    • this is more amenable for sperm movement
  14. Where is there a squamocolumnar junction in the female reproductive system?
    • at the external os of the cervix, which is the part that opens into the vagina
    • going from a stratified squamous (SSNKE) epithelium in the vagina to a columnar epithelium in the cervix
    • Image Upload 8
  15. Transformation Zone (SSNKE → Simple Columnar) Location
    in women of reproductive age: external os

    before puberty & after menopause: within the cervical canal

    • *metaplasia in this zone constitutes pre-cancerous lesions
    • Image Upload 9
    • this is a region within the cervix
  16. Vaginal Wall
    • epithelium: SSNKE
    • occasionally there'll be keratohyaline granules present
    • is subject to cyclical changes: as estrogen levels ↑ (from growing follicle) → glycogen production to nourish bacteria lactobacillus vaginalis 
    • they produce acid which prevents growth of pathogens
    • vaginal mucosa is filled with BVs; it sends up papilla-like structures to increase SA of attachment between SSNKE & the underlying CT
    • the muscle layer is mostly smooth, although there is skeletal near vaginal opening
    • Image Upload 10
  17. What is not present in the vaginal wall?
    • GLANDS
    • there are no glands in the vagina
    • all lubrication comes from the cervical glands, vestibular glands, or plasma transudate from BVs
  18. Mammary Glands
    • are compound alveolar glands
    • have lots of ductular regions all connected in one central spot (nipple) through laciferous ducts/sinuses (enlargements)
    • between glandular lobes are CT elements known as Suspensory Cooper's Ligaments
    • glandular portions: TDLUs (terminal duct lobular units)
    • Image Upload 11
  19. What types of secretion occurs in the mammary gland?
    • 1. merocrine - for protein portions of milk
    • 2. apocrine - for lipid components of milk
  20. Mammary Endocrine
    • Prolactin from lactotrophs of the anterior pituitary stimulates milk production
    • Oxytocin stimulates milk ejection      into ducts (myoepithelial contraction)
  21. What are the components of an inactive mammary gland?
    • mostly ducts, no secretory alveoli
    • only glandulated parts are the ducts
    • Image Upload 12
    • see lots of CT, & duct portions from which secretory portions have the potential to sprout
  22. What do mammary glands look like during pregnancy?
    • increased proliferation of ducts & secretory alveoli
    • Image Upload 13
    • there's a huge proliferation of secretory parts
    • lots of lobules
    • less CT
    • fair amount of adipose tissue as well
  23. What do mammary glands look like during lactation?
    • they contain many secretory alveoli & ducts but very little stroma
    • Image Upload 14
    • gland is filled with terminal duct/lobular units
    • can see product (lipid + protein) in the secretory parts & ducts
  24. Menstrual Cycle Phases (4)
    • 1) Menstrual Phase: days 1-5
    • 2) Proliferative Phase: days 5-14
    • estrogen levels rise, stimulate re-growth of endometrium functional layer
    • 3) Secretory Phase: days 14-27
    • estrogen levels peak then fall
    • progesterone levels are high
    • if no fertilization occurs, corpus luteum degenerates, estrogen & progesterone levels fall, and the secretory endometrium enters the ischemic phase
    • 4) Ischemic Phase: days 27-28
    • progesterone & estrogen levels fall rapidly & the functional endometrium becomes ischemic
Card Set
Female Reproductive: Accessory Organs
Histology Exam 4