36. Histology of Menstrual Cycle Flashcards
What are the 2 simultaneous cycles associated with the menstrual cycle?
Ovarian cycle
Uterine cycle
During the ovarian cycle, several ovarian follicles, each housing a primary oocyte, undergo _______ in preparation for ovulation
During the uterine cycle, the ______ prepares for implantation. If fertilization does not occur, this part is shed and menstruation occurs
Folliculogenesis
Endometrium
What are the 4 functions of the paired uterine tubes (oviducts)?
- Catch ovulated secondary oocyte
- Nourish oocyte and sperm
- Provide fertilization microenvironment
- Transport embryo to uterus
Regions of the oviducts:
Proximal ______ with fimbriae
Long and thin-walled _____
Short and thick walled _______
______ portion which opens into the uterus
Infundibulum
Ampulla
Isthmus
Intramural
The ampulla and isthmus are lined by ______ that project into the lumen
Mucosal folds
What are the histological layers of the uterine tubes?
Mucosal layer
Smooth muscle layer
Serosa layer
The mucosal layer of the uterine tube is a _______ epithelium with an underlying lamina propria. It is lined with _____ cells that change under the influence of hormones throughout the menstrual cycle. There are also ________ cells which secrete nutrients for the egg during migration
Simple columnar; ciliated; nonciliated secretory cells (peg cells)
What changes occur in the ciliated cells of the mucosa of uterine tubes under the influence of estrogen vs. progesterone?
During folliculogenesis, estrogen is high, the ciliated cells enlarge, growing in height and producing cilia
During luteolysis, progesterone is high, the cells lost their cilia and decrease in height
[so CILIOGENESIS is ESTROGEN-DEPENDENT]
Describe the smooth muscle layer of the uterine tubes
Has inner circular-spiral layer and outer longitudinal layer
Function = peristaltic contraction (along with ciliary activity of epithelial cells) propel the oocyte/zygote toward uterus
3 layers of uterine wall and epithelium type
Endometrium = simple columnar w/simple tubular glands
Myometrium = poorly defined smooth muscle + stratum vasculare
Perimetrium = serosa covering posterior surface and part of anterior surface (rest is adventitia)
What 2 layers exist within the endometrium of the uterus?
Functional layer (stratum functionale) — lost during menstruation; supplied by spiral arteries
Basal layer (stratum basale) — retained during menstruation
The myometrium of the uterus has a central, circular layer that is thick with blood vessels, constituting the _____ ______. Outer and inner layers contain _____ and ______ arranged fibers
Stratum vasculare; longitudinally; obliquely
In terms of endometrium vasculature, _____ arteries supply the endometrium. These arteries have a _____ segment that supplies the basal layer, as well as a _____ segment supplying the functional layer which must stretch with endometrial growth
Arcuate; straight; coiled (spiral aa.)
What happens at the straight-coiled junction of arcuate arteries just before menstruation?
Contraction occurs at this junction, reducing blood flow leading to the destruction of the functional layer
What are the phases of the menstrual cycle?
- Menstrual phase
- Proliferative phase
- Secretory phase
- Ischemic phase
Describe glandular changes in the endometrium during the proliferative phase of the menstrual cycle
During the early proliferative period, the glands of the endometrium are short, straight, and narrow. The lamina propria is compacted.
During the midproliferative period, the glands are longer and straight. The epithelium is mitotically active. The LP is slightly edematous.
During the late proliferative period, mitotic activity is intesnse, the glands grow rapidly and become tortuous. The LP is more edematous
Describe glandular changes in the endometrium during the secretory phase of the menstrual cycle
During the midsecretory period, glycogen accumulates in the basal portion of the glandular epithelial cells. The glands have saw-tooth appearance. Cells of stroma surrounding spiral aa. enlarge and become decidual-like.
During the late secretory period, glycogen shifts to apical portion; glands have secretion in the lumen; stromal cells surrounding spiral aa. are mitotically active an indication of decidual change
During the ______ period, the upper region of the endometrial stroma contains numerous decidual cells. The spiral arteries contract.
Ischemic
The proliferative phase of the menstrual cycle lasts from days ___-____
______ proliferate and cover surface of endometrium
______ arteries elongate and become convoluted, extending from basal into functional layer
This phase is ______-dependent
5-14
Glands
Spiral
Estrogen
During the secretory phase of the menstrual cycle from days ___-____:
Glands are convoluted with “______” appearance
The ______ reaches maximum thickness
Spiral arteries continue to grow and extend into the functional layer, and there is considerable ______ infiltration in the stroma
These phase is dependent upon ____ and _____
15-28
Saw tooth
Endometrium
Leukocyte
Estrogen; progesterone
During the ischemic phase of the menstrual cycle which lasts about 1 day, there is regression of the _______
Reduction in blood supply causes intermittent ischemia and subsequent _____ of the functional endometrial layer
Corpus luteum; necrosis
During the menstrual phase of the menstrual cycle, which lasts ___-____ days:
The _______ has sloughed away as well as numerous RBCs and leukocytes. The ______ remains intact
1-4
Stratum functionalis; stratum basalis
During the premenstrual, or ischemic, stage:
Periodic contractions of the spiral artery, triggered by a reduction in ________, deprive the functional layer of oxygen. A breakdown of the spiral a. floods the ________ with blood
Progesterone; LP
During the ischemic stage of the menstrual cycle, the functional layer, consisting of glands and decidual-like cells, detaches and sheds into the uterine cavity. Why is the stratum basalis not affected?
Because basal straight arteries provide independent blood supply to this layer
If pregnancy takes place, ______ cells in the LP increase in size as they store lipids and glycogen
The ___________ occurs when functional layer is shed as [above answer] at parturition
Decidual
Decidual reaction
Decidual cells derive from the epithelial-like transformation of endometrial stromal cells (decidual reaction in preparation for embryo implantation). What are the primary functions of decidual cells?
Modulate trophoblast cell invasion
Provide nutrients to the developing embryo
Prevent immunologic rejection
Endocrine role in production of decidual prolactin which has a trophic effect on corpus luteum
What vascular changes occur in the endometrium in response to embryo implantation?
Increase in permeability of endometrial blood vessels and angiogenesis
Recruitment of what types of inflammatory cells occurs at implantation site?
Lymphocytes
Macrophages
Eosinophils
In addition to decidual prolactin, decidual cells produce _____ and _____
Prostaglandins; relaxin
_________ = condition in which clusters of endometrium become implanted outside the uterus, forming _______
Endometriosis; endometriomas
What are common locations for endometriomas?
Oviduct Ovaries Sigmoid/ascending colon Broad and uterosacral ligaments Pelvic peritoneal lining
Tx for endometriosis
OCPs
Drugs to induce menopause
Laparoscopy/ablation or hysterectomy
IVF for fertility management
Endometriosis can give rise to cysts, scar tissue, and peritoneal adhesions, as well as what other conditions relating to the menstrual cycle?
Dysmenorrhea
Menorrhagia
Menometrorrhagia
Infertility
_____ = chronic pelvic pain occurring during menstruation
Dysmenorrhea
Excessive bleeding during the menstrual period
Menorrhagia
Bleeding between periods
Menometrorrhagia
Endometriosis is commonly first diagnosed in patients who present with what concern?
Infertility
The cervix communicates with the uterine cavity through the ______, which is characterized by folded mucosa with deep _____ that mimic mucous secreting tubular glands
Endocervix; crypts
Cervical crypts increase the surface area of mucous producing _____ _____ cells. Height of crypts varies with time of the menstrual cycle and secretory activity. They can become occluded and dilated, forming ____ ______
Simple columnar
Nabothian cysts
_______ of cervix contains collagen bundles, some smooth muscle, and abundant vasculature
Stroma
Ectocervix = external segment of cervix, lined by ____ ____ epithelium
Stratified squamous epithelium (nonkeratinized)
[contrast with simple columnar of endocervix]
_________ = important area in cervix where epithelium changes between endocervix and ectocervix
Transformation zone
About 95% of cervical intraepithelial neoplasias originates within the _______ ______
Transformation zone
What are the histological layers of the fibromuscular vagina?
Mucosal layer = nonkeratinized strat squamous
Muscularis layer = circular + longitudinal sm. m.
Adventitial layer = dense CT
The mucosal layer of the vagina is kept moist by mucous from the uterine/endocervical glands and glands of ______ in the vestibule
Bartholins
What cyclical changes occur in the histological staining of the vagina relative to ovulation?
Ovulation (estrogen) —> stratified epithelium is fully differentiated and stains acidophilic
After ovulation (progesterone) —> decrease in squamous cells, polygonal cells stain basophilic (also more neutrophils and lymphocytes)
T/F: the vaginal wall lacks glands
True
Vaginal smears provide rapid info on levels of ____ and _______, which makes them useful for monitoring hormonal status during pregnancy
Estrogen; progesterone
The clitoris is located below the mons pubis and is equivalent to the penis, or ______ _____ tissue in the male.
It consists of erectile vascular tissue, with 2 ______, each surrounded by a fibrous collagenouos sheath.
It is partially covered by skin rich with sensory nerves and receptors, but lacks ______ and ______
Corpora cavernosa
Crura
Hair follicles; glands
Dysplasia occurs at which region of the cervix?
Ectocervix
Describe dysplasia of the ectocervix
Disorganized epithelial cells that slough off before reaching full stratified maturity
Can progress into carcinoma — in situ or invasive
Ectocervical dysplasia or carcinoma are detected by what method?
Pap smear
STI associated with majority of cervical cancer cases
HPV
What cells are used to detect high-risk HPV strains?
Cervical cells
There are 13 types of HPV — which 2 are known contributors to cervical cancer?
HPV 16 and HPV 18
_____ _____ = observing normal/abnormal cells using staining
Diagnostic cytopathology
Pap smear is a standard procedure for detection using papanicolaou stain
Eosin stains ______ cells pink or orange
Light green stains the cytoplasm of less differentiated cells close to the ____ ____
Hematoxylin stains ______ dark blue/purple
Superficial squamous
Basal lamina
Nuclei
In a pap smear:
________ stimulate differentiation of superficial layers of the vagina (stratified squamous). With epithelium differentiation (estrogen) —> progesterone causes rapid _________ of the apical pink-orange stained squamous cells
The _________ stained polygonal cells of the intermediate layers remain and are seen in the smear
Estrogens; desquamation
Light green
Describe histology of mons pubis
Keratinized stratified squamous with hair follicles covering subcutaneous fat overlying pubic symphysis
Describe histology of labia majora
Extensions of the mons pubis at each side of the vaginal introitus; pigmented skin with hair follicles and glands (apocrine sweat and sebaceous) covering fat pad
Describe histology of labia minora
Pigmented skin folds with abundant blood vessels, elastic fibers, and sebaceous glands
_____ = limit between the internal and external genitalia consisting of thin fibrous membrane lining lower vagina
Hymen
Describe histology of the hymen, differentiating external vs. internal surfaces
External surface = keratinized stratified squamous
Internal surface = nonkeratinizing stratified squamous
