Mammary Gland and Lactation

Question 1

The four stages of lactation

Answer 1

Mammogenesis
Lactogenesis
Galactopoiesis
Involution

Question 2

Mammogenesis

Answer 2

Development of mammary gland

Question 3

Lactogenesis

Answer 3

Initial production of milk

Question 4

Galactopoiesis

Answer 4

Secretion and continued production of milk

Question 5

Involution

Answer 5

Atrophy of secretory cells caused by no more suckling, decreased prolactin, and decreased GnRH

Question 6

Mammary gland anatomy from large to small

Answer 6

Lobe –> Lobule –> Alveolus

Question 7

What hormone stimulates alveolar growth?

Answer 7

Progesterone

Question 8

What hormone stimulates duct growth?

Answer 8

Estrogen

Question 9

Hormones involved in mammary gland development

Answer 9

Progesterone
estrogen
growth hormone

Question 10

Hormones involved in MG development during pregnancy

Answer 10

Prolactin
Adrenal corticosteroids
Placental lactogen

Question 11

What triggers lactogenesis?

Answer 11

Increase in prolactin and decrease in progesterone

Question 12

Species with inguinal mammary glands

Answer 12

Ruminants, mare

Question 13

Species with thoracoabdominal mammary glands

Answer 13

Dog, cat, pig

Question 14

Species with thoracic mammary glands

Answer 14

Primates, elephants

Question 15

Mammary gland function

Answer 15

Product colostrum

Nutrition

Question 16

Colostrum

Answer 16

“first milk”

provides passive transfer of immunoglobulins (mostly IgG)

Question 17

Relationship between placentation type and passive transfer

Answer 17

Less invasive placentation = more reliance on colostrum for passive transfer of immunoglobulins

Epitheliochorial > endotheliochorial > hemochorial

Question 18

Factors affecting colostrum quality

Answer 18

Age
Number of lactations
Vaccination status
Health
Volume of colostrum

Question 19

Reasons passive transfer fails

Answer 19

Inadequate supply from dam
Failure to suckle
Failure to absorb into bloodstream

Question 20

Hormones that stimulate galactopoiesis

Answer 20

Prolactin and growth hormone

Question 21

Hormone that stimulates milk letdown

Answer 21

Oxytocin (release caused by suckling)

Question 22

How can milk letdown be blocked?

Answer 22

Adrenaline from nerve endings overcomes let down hormone action

Question 23

Galactopoiesis regulation

Answer 23

More milk removal = more milk production

Less milk removal –> pressure atrophy = less milk production

Question 24

Lactogenesis exocytosis

Answer 24

1. Casein and lactose secreted

Question 25

Lactogenesis lipid

Answer 25

2. Fat globule released

Question 26

Lactogenesis apical transport

Answer 26

3. Water and electrolytes

Question 27

Lactogenesis transocytosis

Answer 27

4. secretory IgA, hormones, growth factors (IGF-1)

Question 28

Lactogenesis paracellular

Answer 28

5. transport of IgG and leukocytes