Lactation Flashcards
Define mammogenesis
Mammary growth at puberty or during pregnancy
Define lactogenesis
Initiation of milk secretion at parturition (production of colostrum)
Define galactopoeisis
Continued milk secretion during lactation
Describe the embryological development of the mammary glands
- originate from epidermis
- Arise along 2 lateral lines on ventral surface of developing foetus
- Called mammary ridge, thickened epidermal tissue, give rise to primary mammary bud
- Extend from axillary region to inguinal region
- Primary bud pushes into dermis to grow
- Branch into secondary mammary bud
- Will then branch out and canalise to form lactiferous ducts
- Myoepithelial cells from mesoderm
Outline the significane of lactation
- Free neonate from dependency on other foods
- Allows offspring to continue development outside uterus
- Sovial development and bonding
- Natural contraception
- Foetus born with minimal fat for ease of birth
Outline the adaptation allowing neonates to suckle and breath at the same time
Long hard palate, not present in birds
Describe the anatomy of the mammary gland
- Glandular tissue, secretory epithelial cells and excretory ducts
- Excretory ducts empty into gland cistern
- Epithelial cells surrouding spherical lumen = alveolus (aka alveolar cells)
- Myoepithelial cells around each alveolus and ducts
- Groups of alveoli form lobules
- Groups of lobules form lobes
- As each gland develops, get development of a teat sinus
- Some have internal sphincter in teat/streak canal
Where is the majority of control in the mammary gland?
In the teat/streak canal
What is the function of the myoepithelial cells?
Contraction will propel milk out of alveoli and into ducts
What speecies have thoracic mammary glands?
- Man and other primates
- Elephant
What species have abdominal mammary glands?
- Dog
- Cat
- Sow
- Rat
- Rabbit
What species have inguinal mammary glands?
- Goats, sheep
- Cow
- Guinea pig
- Mare
Which species have 2 mammary glands?
- Man and other primates
- Elephant
- Goats, sheep
- Guinea pig
- Mare
How many mammary glands do dogs have?
~10
How many mammary glands to cats have?
8
How many mammary glands to pigs have?
8-18
How many mammary glands do rats have?
~10
How many mammary glands do rabbits have?
10
How many mammary glands to cows have?
4
How many teat canals per teat do humans, elephants and rabbits have?
8-10
How many teat caals do dogs have per teat?
8-22
How many teat canals per teat do cats have?
4-8
How many teat canals per teat do sows and mares have?
2
Which species have 1 teat canal per teat?
- Rats
- Goats, sheep
- Cows
- Guinea pigs