Placenta and Breast histology

Question 1

Endometrial Invasion

Answer 1

secretory phase of endometrium is required
- trophoblast proliferation -> lacunar formation
- decidual reaction
Cytotrophoblasts divide and form into synctiotrophoblasts
- synctiotrophoblasts are not mitotically active

Question 2

Chorionic Villi

Answer 2

Contain:

1. extraembryonic mesoderm
2. Cytotrophoblasts
3. Syncytiotrophoblasts

Question 3

Primary Villi

Answer 3

trophoblasts only, no mesoderm yet

Question 4

Secondary Villi

Answer 4

mesodermal outgrowths and villus core

Question 5

Tertiary Villi

Answer 5

differentiation of blood vessels in villus core

- eventual anastamoses of villar blood vessels with fetal circulation

Question 6

Decidua basalis

Answer 6

between conceptus and myometrium

• constitues maternal portion of placenta
• site of decidual reaction and most extensive villar invasion
• lots of glycogen

Question 7

Decidua capsularis

Answer 7

between conceptus and uterine lumen

Question 8

Decidua parietalis

Answer 8

remainder of endometrium

Question 9

Cotyledons

Answer 9

placenta divided into 15-30 lobules by septae

- contain 2-4 tertiary villi with their branches

Question 10

Fetal Circulation

Answer 10

umbilical arteries –> chorionic arteries –> villar capillaries –> chorionic veins –> umbilical vein

Question 11

Maternal Circulation

Answer 11

spiral arteries –> intervillous space (lacunar network) –> endometrial veins

Question 12

Hofbauer Cells

Answer 12

placental macrophages

Question 13

Placental Barrier 1st trimester

Answer 13

Syncytiotrophoblasts
Cytotrophoblasts
Basal lamina of trophoblasts
Fetal CT
Basal lamina of fetal capillaries
Fetal endothelium

Question 14

Placental barrier after 1st trimester

Answer 14

Thinner barrier
Synctiotrophoblasts
Basal lamina
Fetal Capillaires

Question 15

Placental Hormones

Answer 15

most are syncytiotrophoblast origin

• hCG -> maintenance of corpus luteum
• human placental lactogen -> closely related to GH, stimulates growth, lactogenic
• progesterone and estrogen
• prolaction, PGs, relaxin (softens cervix and pelvic ligaments

Question 16

Basic organization of mammary gland

Answer 16

specialized cutaneous gland -> modified sweat gland

• each lobe is an independent gland separated by dense interlobar CT
• ducts open at apex of nipple
• intralobular CT is loose and delicate

Question 17

Order of ducts

Answer 17

Intralobular duct –> interlobular duct –> lactiferous duct –> lactiferous sinus –> lactiferous duct

Question 18

Lactiferous sinus

Answer 18

dilation of lactiferous duct just before it opens into summit of nipple

Question 19

Epithelium of ducts

Answer 19

simple cuboidal in ducts

- stratified squamous near opening of nipple

Question 20

Changes at puberty

Answer 20

glands enlarge rapidly -> due to development of adipose and CT
remain incompletely developed until pregnancy

Question 21

Areola and Nipple

Answer 21

skin is pigmented (no sweat or hair follicles)
- stratified squamous keritanizing -> melanin increases during pregnancy
- lots of Meissner’s corpuscles
Smooth muscle is longitudinally and circumferentially arranged

Question 22

Secretory unit

Answer 22

alveoli - cuboidal to squamous epithelium

• distal ends of intralobular ducts
• proteins and salts = merocrine secretion
• milk/fat = apocrine secretion

Question 23

Myoepithelial cells

Answer 23

make alveoli look stratified, assist in contraction and excretion of milk

Question 24

Inactive gland

Answer 24

alveoli have flattened cuboidal

extensive CT and adipose

Question 25

Pregnancy

Answer 25

intralobular ducts proliferate and branch - increase in alveolar # and epithelium height - colostrum production (rich in protein, low lipid, IgA) - decrease in CT

Question 26

Lactation

Answer 26

alveoli - active (dilated, cuboidal, milk rich in lactose, protein, lipids, and IgA)

Question 27

Regression

Answer 27

absorption of secretory products alveolar size decreases and degenerates increase CT and adipose

Question 28

Involution

Answer 28

``` postmenopausal atrophy of gland parenchyma and stroma few ducts cyst formation CT becomes dense ```

Question 29

Puberty --> Pregnancy

Answer 29

estradiol stimulates duct proliferation Progesterone stimulates alveolar proliferation prolactin = dropping levels of progesterone and estrogen after birth --> prolactin is enhanced