Histology of Mammary Gland and Placenta

Question 1

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Answer 1

Question 2

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Answer 2

Umbilical

Question 3

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Answer 3

Placenta (First trimester)

Question 4

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Answer 4

Question 5

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Answer 5

Question 6

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Answer 6

Question 7

Mammary Alveoli

Answer 7

Question 8

The placenta erodes into both the _________ and ______.

Answer 8

Endometrial glands; spiral arteries

Question 9

What are the stages of placenta development?

Answer 9

• 7 1/2 day implanting blastocyst
• 9 day implanted blastocyst
• 16 day embryo

Question 10

Function of chorionic villi?

Answer 10

Chorionic villi are villi that sprout from the chorion in order to give a maximum area of contact with the maternal blood

NOTE: Chorionic villi penetrate into endometrium

Question 11

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Answer 11

Question 12

Characteristics of placenta in first trimester

Answer 12

• Chorionic villi are large and covered by two layers of cells- cytotrophoblast and syncytiotrophoblast
• Blood vessels are not prominent

Question 13

Characteristics of placenta in second trimester

Answer 13

• The villi becomes smaller
• More vascular
• Syncytiotrophoblast cell layer draws up into “syncytial knots” which are small clusters of cells, leaving a single cytotrophoblast layer

Question 14

Characteristics of placenta in third trimester

Answer 14

• Branches of the umbilical vessels grow into the mesoderm
  
  • In this way, the chorionic villi are vascularized to support the blood glas and nutrient exchange of maternal-fetal circulation
• Syncytial knots and intervillous fibrin are prominent

Question 15

Which hormones are synthesizes by the placenta?

Answer 15

• hCG
• Somatommammotropin
• Progesterone

Question 16

The syncytiotrophoblast is permeable to:

Answer 16

• Ions
• Nutrients
• Maternal IgG
• Some drugs

Question 17

Which drugs have the highest fetal/maternal ratio?

Answer 17

Ketamine (1.26)

*This is an intravenous anesthetic

Question 18

Which drugs have the lowest fetal/maternal ratio?

Answer 18

Lidocaine (0.5)

*This is a local anesthetic

Question 19

Cause of pre-eclampsia

Answer 19

Elevated blood levels of a protein (sFIt-1) that binds growth factors required for normal placental growth

NOTE: Pre-eclampsia is a result of poor placental invasiveness and poor vascularization.

Question 20

Components of milk secreted by mammary glands

Answer 20

• Lactose (Golgi)
• Protein (RER)
  
  • Casein
  • Lactoferrin
  • IgA
• Lipid (cytosol)
  
  • Triglycerides and cholesterol
• Antibodies (plasma cells)
• Ions

NOTE: Mammary glands contain 16-20 lobules

Question 21

Stages in the functional anatomy of the mammary gland

Answer 21

• Nonpregnant
  
  • ​Inactive duct system
• During pregnancy
  
  • ​Alveoli proliferate at the ends of the ducts
• Lactating
  
  • ​Milk secretion and accumulation in alveolar lumen

Question 22

Differentiate between inactive and active mammary glands

Answer 22

In active:

• Amount of glandular tissues increases
  
  • Involves both the epithelial and myoepithelial cells
  • Proliferation of these cells leads to the formation of secretory alveoli
• Connective tissue decreases
• Increased cellularity of intralobular connective tissue
• Intralobular ducts have proliferated to form additional secretory regions

Question 23

Characteristics of inactive mammary gland

Answer 23

• Abundant connective tissue
• Sparser glandular componnent consists largely of ducts
• Ducts are surrounded by loose connective tissue containing lymphocytes, plasma cells and fibroblasts
• Beyond a lobule is the connective tissue is more dense
• The dense connective tissue contains aggregates of adipocytes

Question 24

Which type of epithelium line the laciferous ducts?

Answer 24

Stratified squamous epithelium

Question 25

Which type of epithelium line the laciferous sinus?

Answer 25

Stratified cuboidal epithelium \*The remainder of the duct system is lined by a single layer of columnar or cuboidal cells

Question 26

Myoepithelial cells are of _________ origin.

Answer 26

Ectodermal **NOTE:** Myoepithelial cells lie within the epithelium between the surface epithelial cells and the basal lamina. They are present in the **ductal and secretory portion of the gland**

Question 27

Inactive vs Proliferating vs Lactating Histology

Answer 27

Question 28

Milk secretion depends on the action of which two epithelial cell types?

Answer 28

**Myoepithelial cell** * Contract to aid in the ejection of milk **Luminal Epithelial cell** * Secrete the milk into the ductal lumen

Question 29

What are the methods of milk secretion?

Answer 29

**Mecrocrine** * Secretory vesicles coalesce with the membrane on the apical surface to release the product * Protein component **Apocrine** * Lipid droplets pass to the apical region of the cell * Droplets are invested with an envelope of plasma membrane and a thin layer of cytoplasm as they are released into the lumen of the acini * Lipid component