Histology - Female Genital Tract and Pregnancy

Question 0

Example of autocrine signaling in female gen tract

Answer 0

Activin from granulosa cells up regulates FSH receptors on their surface

Question 1

Example of paracrine signaling in female gen tract

Answer 1

Inhibin from granulosa cells act on theca interna (assists LH in androstenedione synthesis)

Question 2

What is cortex of ovary lined by

Answer 2

Simple cuboidal/ squamous epithelium (tunica albuginea)

Question 3

Epithelium of endocervical canal

Answer 3

Mucus secreting simple columnar epithelium

Question 4

Epithelium of ectocervix

Answer 4

Stratified squamous epithelium

Question 5

Development of transformation zone

Answer 5

Estradiol causes eversion of endocervical canal and columnar epi exposed to acidic pH. Squamous metaplasia (epidermalisation)

Question 6

Risks associated with transformation zone

Answer 6

1. Infection (early puberty)
2. Nabothian cyst
3. Dysplasia
4. Carcinoma

Question 7

Epithelium of vagina

Answer 7

Stratified squamous epithelium (produces glycogen under influence of estriol)

Question 8

Role of glycogen in vaginal

Answer 8

Lactobacilli convert glycogen to lactic acid creating an acidic pH

Question 9

Vaginal lubricated by

Answer 9

(Vaginal lacks glands)
Uterine glands
Endocervical glands
Glands of Bartholin (vestibules)

Question 10

Epithelium of uterine tubes

Answer 10

Simple columnar epi.
Ciliated - larger in follicular phase, estrogen increases motility.
Secretory (peg) cells - increase secretion w estrogen

Question 11

Fx of secretions in uterine tubes

Answer 11

Capacitation of sperm

Nutrients for ovum, sperm, morula

Question 12

Features of atretic follicles

Answer 12

Delamination of granulosa cells (pyknotic nuclei, apoptotic bodies)
Collapse
Fibrous body -> corpus albicans

Question 13

Five stages of follicular development

Answer 13

Primordial follicle
Primary follicle - unilayered
Primary follicle - multilayered 
Secondary follicle
Graafian follicle

Question 14

Three regions of granulosa cells in Graafian follicle

Answer 14

Mural granulosa cells
Cumulus oophorous
Corona radiata

Question 15

When is dominant follicle determined

Answer 15

Day 7

Question 16

How is steroid produced in follicle

Answer 16

Granulosa cells lack enzymes to generate steroid. Therefore, theca interna cells produce androstenedione which is taken up by the GCs and converted to estradiol by aromatase

Question 17

Role of follicle hormones in estradiol synthesis

Answer 17

Activin - released by GCs up regulates FSH receptors on GCs (autocrine)

FSH - increases aromatase activity in GCs. Increases the expression of inhibin in GCs

Inhibin - acts on theca interna (paracrine) assisting LH in androstenedione synthesis

Question 18

What does LH surge do

Answer 18

1. Halts estrogen production
2. Initiates 2nd meiotic division (block oocyte maturation-inhibitory substance of GCs)
3. Increase local prostaglandin production (vascular changes = follicle swelling, proteolytic enzyme action on ovary stroma)
4. Differentiate follicular cells to form granulosa lutein cells (take up cholesterol)

Question 19

Formation of corpus luteum

Answer 19

BM breaks down. Invasion of blood vessels into theca lutein. LH causes cholesterol uptake. Theca lutein produces progesterone and androstenedione.
FSH still needed for aromatase

Question 20

Changes seen in uterine cycle from proliferators phase -> secretory phase

Answer 20

Endometrium thin -> thick
Glands straight/tortuous -> saw toothed, many secretions
Cells low/tall -> basal/apical glycogen
Stroma Mitotic figures -> large decidual-like/ oedema and lymphocytes

Question 21

What happens in ischemic phase of uterine cycle

Answer 21

Release of prostaglandins = spiral artery spasm. Hypoxia = stroma flooded w blood. Functional layer shed. Basal layer remains intact (straight arteries)

Question 22

Eversion of endocervical canal forms

Answer 22

Ectropion

Question 23

Process of female sexual arousal

Answer 23

Parasympathetic activation - engorgements of clitoris.
Increased vaginal excretions.
Engorged blood vessels.
Orgasm - peristaltic contractions of vaginal/uterus.
Pudendal nerve = rhythmic contraction (bulbosongiosus/ ischiocavernosus)

Question 24

Effect of contraceptive pill

Answer 24

1. HP axis - inhibits synthesis/secretion of FSH. Therefore, no follicle maturation/ LH surge/ ovulation. 2. Cervix - cubical mucus thicker, more hostile. Prevents sperm entry. 3. Endometrium - lining thins, alters tubes (ovum can't travel easily)

Question 25

Mechanism of morning after pill

Answer 25

Synthetic progesterone prevents implantation

Question 26

Mechanism of estrogen-progesterone-glucocorticoid receptor antagonist

Answer 26

Non supportive endometrium

Question 27

Mechanism of prostaglandin E2 contraceptive

Answer 27

Uterine contractions

Question 28

Role of estrogens in the female

Answer 28

Many genital tract changes Bone deposition Cardiac protection (cholesterol metabolism, antioxidant, vasodilation, regulates arterial muscle proliferation after injury) Modulates E and NE actions

Question 29

Fx of syncytiotrophoblasts

Answer 29

1. Release proteases - erode maternal tissue 2. Secrete hCG - maintain corpus luteum 3. No MHC 4. Line inter villus space 5. Microvilli brush border increases SA for exchange

Question 30

Fx of cytotrophoblasts

Answer 30

1. Syncytiotrophoblast precursor 2. Secretes FAS ligand - kills T cells 3. Anchors villus stem to decidua by secreting fibrinogen substance 4. Invasion of spiral arteries to form maternal sinusoids and regulate blood flow (poor invasion = abortion, eclampsia, growth retardation)

Question 31

Immune protection mechanisms in placenta

Answer 31

Decidua - prostaglandins inhibit NK cells. Infiltration leukocytes secrete IL 2 Inter villus space - IgGs Chorionic villi - syncytiotrophoblasts have no MHC. Cytotrophoblasts secrete FAS ligand Hofbauer cells in early pregnancy = phagocytosis

Question 32

Describe process of blastocyst attachment

Answer 32

1. Blastocyst hatches from zona pellucida 2. Trophoectoderm binds uterine surface 3. Primary decidual zone formed (cells proliferate, ECM proteins laid down, various proteins released) 4. Vasculature becomes permeable at implantation site.

Question 33

Describe process of blastocyst implantation

Answer 33

1. Trophoectoderm invades uterine luminal cells which undergo apoptosis. 2. Reduced desmosomes helps embryo penetration. 3. Secondary decidual zone replaces primary zone.

Question 34

What makes secondary villus different to primary

Answer 34

Extraembryonic mesodermal core

Question 35

Role of decidua cells

Answer 35

Luteal phase - secrete decidual prolactin -> GF for corpus luteum After implantation - modulate trophoblast implantation, provide nutrients for embryo, prostaglandins inhibit NKs, secrete relaxin, secretes IGF binding protein preventing endometrial gland proliferation, prostaglandins regulate blood flow.

Question 36

How is estrogen produced in pregnancy

Answer 36

Fetoplacental unit. Cholesterol -> pregnenalone -> progesterone in placenta Progesterone -> DHEA in fetal adrenals DHEA -> estrogen in placenta

Question 37

What is the placental luteal shift

Answer 37

Chorionic gonadotropin used instead of LH to maintain the corpus luteum

Question 38

Why may glucose and insulin be high in preg woman

Answer 38

Human chorionic somatomammotropin (placental lactogen) increases liver resistance to insulin. [ structure similar to GH and prolactin ]

Question 39

Role of human chorionic somatomammotropin

Answer 39

Fetal growth | Mammary gland development

Question 40

Pregnancy's effect on maternal physiology

Answer 40

``` Alveolar respiration (>progesterone) Tidal volume Maternal blood volume Nutrient requirements GFR Uterus size Mammary gland growth + development ```

Question 41

Role of cortisol in parturition

Answer 41

Fetal lungs exposed to more pulmonary surfactant = maturation Surfactant protein in amniotic fluid = macrophages causing increase prostaglandin production.

Question 42

Role of estrogen in triggering parturition

Answer 42

Increase number of gap junctions = synsytium Increase oxytocin receptors in myometrium = increased responsiveness to low levels of oxy Increase prostaglandin production = cervical softening

Question 43

Describe process responsible for progression of parturition

Answer 43

Oxytocin causes uterus to contract. Fetus pushed against cervix -> ferguson reflex causes more oxytocin release increasing prostaglandin production and causing more contraction (positive feedback cycle)

Question 44

Structure where all mammary glands meet

Answer 44

Lactiferous sinus

Question 45

What inhibits lactation

Answer 45

High levels of estrogen | Dopamine

Question 46

Constituents of colostrum

Answer 46

Proteins (merocrine) Lipids (apocrine) Lactose -> draw water into milk by creating osmotic gradient

Question 47

What initiates lactation

Answer 47

Increase cortisol -> milk synthesis enzymes induced | Rapid fall in estrogen overrides dopamine's inhibitory effect

Question 48

How is prolactin secretion controlled

Answer 48

Dopamine inhibits prolactin. Suckling inhibits dopamine release allowing increase in prolactin stimulating galactopoeisis. Suckling also stimulates oxytocin release causing contraction of myoepithelial cells. NB prolactin inhibits GnRH therefore no menses

Question 49

Other functions of oxytocin

Answer 49

Pair bonding with sexual partner | Maternal behavior

Question 50

Cells seen on Pap smear (normal)

Answer 50

Large squamous epithelial cells with pyknotic nuclei = surface epithelium. Can be acidopholic (Pre) or basophilic (post) ovulation. Columnar cells of endocervix indicates that the TZ and squamocolumnar junction cells are present