Female Histology

Question 1

Ovary Functions

Answer 1

Exocrine -> production of eggs and secretion

Endocrine -> estrogen production (theca interna, granulosa), progesterone production (corpus luteum after ovulation)

Question 2

Oviduct Functions

Answer 2

Fallopian tubes

- ovum pick-up, sperm transport, site of fertilization, egg nourishment, conduit for transmission of infections

Question 3

Uterus Functions

Answer 3

Implantation site for conceptus

Question 4

Vagina Functions

Answer 4

copulatory receptacle, birth canal

Question 5

Mammary Gland Functions

Answer 5

milk production

Question 6

Ovary organization

Answer 6

suspended by mesovarium (broad ligament), peritoneal covering (germinal epithelium), hilum (attachment of mesovarium and conduit for blood vessels and lymphatics)

Question 7

Zones of Ovary

Answer 7

Cortex -> outer layer (where all the action happens)
- tunica albuginea, directly underneath germinal epithelium
- stroma, compact, CT with reticular fibers and follicles embedded in stroma
Medulla -> inner layer (loose fibroelastic CT, blood vessels)

Question 8

Primordial Germ Cells

Answer 8

• Yolk sac origin, mitotic proliferation, migration to primordium of ovary, diploid cells
• 3rd fetal month -> oogonia become primary oocytes and become arrested in prophase I until puberty
• Puberty -> primary oocytes finish maturation and become secondary oocytes and arrest in metaphase II (until fertilization)

Question 9

Primordial Follicles

Answer 9

Primary oocyte arrested in prophase I until just before ovulation
- follicular cells -> single layer of flattened cells that have FSH receptors

Question 10

Primary Follicles

Answer 10

20-50 primordial follicles respond to FSH every cycle

• oocyte enlarges and follicular cells become granulosa cells (convert androgen to estrogen)
• theca folliculi also develop (androgen production)
• zona pellucida develops (gel-like glycoprotein) -> ZP 3 is what binds to spermatozoa
• after menarche, 1 follicle becomes dominant follicle, all others undergo atresia

Question 11

Secondary Follicles

Answer 11

Still in prophase I arrest –> antrum formation

• Antrum -> liquor folliculi production with GAGs, proteins, gonad hormones, FSH, inhibin, electrolytes
• Granulosa cells -> become cumulus oophorus that surrounds oocyte
• Theca folliculi -> 2 distinct portions, theca interna (highly vascular, androgen production), theca externa (smooth muscle like, no known function)

Question 12

Mature Follicles (Graafian)

Answer 12

Total maturation takes 3 months

• Corona radiata -> follicle cells in direct contact with egg
• Theca folliculi -> greatest development
• LH signals maturation -> oocyte resumes maturation, becomes arrested in metaphase II (first polar body formed)

Question 13

Ovulation

Answer 13

1. LH surge –> granulosa and theca cells receptive
2. Primary follicle responds
3. Meiosis I is complete (first polar body)
4. Arrest in metaphase II
5. Stigma formation (wall weakening of tunica albuginea, decreased blood flow)
6. Rupture and expulsion of cumulus mass
7. Ovum capture by oviductal fimbria

Question 14

FSH

Answer 14

granulosa cells growth and estrogen synthesis

- later, FSH stimulates an increase in LH receptors

Question 15

LH

Answer 15

stimualtes theca cell growth and androgen production

• granulosa cells convert androgen to estrogen
• stimulates progesterone production of granulosa cells

Question 16

Corpus Luteum

Answer 16

temporary glandular structure -> derived from ruptured follicle after ovulation
- follicular cavity closes by healing stigma
Granulosa cells -> increase greatly in size = granulosa lutein cells (produce progesterone and estrogen)
Theca Interna cells -> increase in size = theca lutein cells
*if embryo doesn’t develop -> involution occurs and scar forms
*if pregnany -> becomes large because of hCG stimulation until 2nd trimester, then involutes

Question 17

Estrogen

Answer 17

produced by growing follicles

• induces maturation of female reproductive tract and mammary glands
• directs repair of uterus following menstruation

Question 18

Progesterone

Answer 18

produced primarily by corpus luteum

• causes uterine glands to secrete
• prepares uterus for implantation of ovum
• aids in growth of mammary glands
• inhibits premature uterine contractions

Question 19

Relaxin

Answer 19

produced by corpus luteum and decidual cells (placenta)

• inhibits contractions by myometrium
• promotes dilation of cervix

Question 20

Inhibin

Answer 20

follicular fluid -> negative feedback on FSH release

Question 21

Atretic Follicles

Answer 21

99% of follicles undergo atresia

- just doesn’t look healthy -> entire structure is replaced by scar tissue

Question 22

Ampulla

Answer 22

elaborate branching folds -> largest diameter
- simple columnar, ciliated epithelium
Estrogen -> increases # of ciliated cells and secretion of secretory cells
Progesterone -> increases # of secretory cells

Question 23

Isthmus

Answer 23

fewer folds than ampulla, reduced ciliated cells, active secretory cells

Question 24

Intramural Segment

Answer 24

Barely any folds and no cilia

Question 25

Muscularis layer of oviduct

Answer 25

all 3 segments have thick inner circular layer and thin outer longitudinal layer - tubal peristalsis helps embryo transport through isthmus

Question 26

Endometrium of uterus

Answer 26

Simple tubular glands, simple columnar epithelium (ciliated at gland apex, secretory) - lamina propria -> mesenchymal cells - Basal layer -> deepest layer (regenerate functional layer) -> straight arteries - Functional layer -> superficial and deep spongy layer (helical arteries)

Question 27

Myometrium of uterus

Answer 27

Smooth muscle arranged in 3 layers, hard to identify distinct layers - Cyclical hormone response -> muscle fibers shortest during first week of menstruation, longest during 4th week of cycle - Pregnancy -> hypertrophy and some hyperplasia

Question 28

Perimetrium of uterus

Answer 28

outer mesothelial lining

Question 29

Blood supply to uterus

Answer 29

Uterine arteries -> arcuate arteries -> split between straight arteries (basal layer) and spiral/helical arteries (functional layer) --> capillaries

Question 30

Menstrual Cycle

Answer 30

``` Proliferative Phase Secretory Phase Premenstrual Phase Menstrual Phase Repair Phase ```

Question 31

Proliferative Phase

Answer 31

Estrogen dependent! -> begins at end of menstrual flow - 2-3x increase in endometrial thickness (mitoses of glands and stroma) - coiled arteries elongate

Question 32

Secretory Phase

Answer 32

Progesterone secretion increases dramatically, estrogen increases as well - endometrial thickness continues (but due to edema, not mitoses) - coiled arteries continue to elongate - massive glycogen accumulation in stroma and glands

Question 33

Premenstrual Phase

Answer 33

corpus luteum begins regression --> decreased steroid output - coiled arteries constrict intermittently -> response to decline in progesterone, anoxia - periodic dilation of coiled arteries -> small hemorrhages and seepage - coiled arteries constrict permanently -> endometrium detachment begins, arterioles bleed into denuded surface

Question 34

Menstrual Phase

Answer 34

functional layer of endometrium undergoes complete necrosis and is shed - venous seepage -> can't clot due to fibrinolysin - denuded surface is rapidly re-epithelialized (migration of cells from glands in basal layer)

Question 35

Cervical Mucosa

Answer 35

many branching cervical glands, mucosa is not shed during menstruation - secretions are cyclical and are least viscous at ovulation -> lets sperm in - simple columnar epithelium --> abrupt transition to stratified squamous nonkeratinizing epithelium at external os (squamocolumnar junction)

Question 36

Myometrium

Answer 36

composed of dense CT | - cervical dilation in pregnancy by relaxin

Question 37

Vagina Mucosa

Answer 37

stratified squamous nonkeratinizing --> estrogen sensitive - follicular phase -> proliferation and hypertrophy of basal cells (glycogen uptake) - luteal phase -> decrease in height, shed into lumen Lamina propria --> many leukocytes - rugae - NO GLANDS -> lubrication comes from cervical glands - glycogen --> metabolized by lactobacilli --> lactic acid production --> decrease in pH

Question 38

External Genitalia

Answer 38

Labia majora -> homologous to skin of scrotum Labia minora -> homologous to skin of penis Clitoris -> erectile tissue homologous to penis Vestible -> stratified squamous epithelium - lesser glands -> mucous glands - great glands -> homologous to bulbourethral glands

Question 39

Sensory nerves of external genitalia

Answer 39

Meissner's corpuscles -> mons pubis and labia majora Pacinian corpuscles -> deeper layers of CT, erectile function Free nerve endings -> occur in large #s, equally distributed