mammary physiology Flashcards
Mammary Physiology quiz 2-1
what are the 4 defining characteristics of mammals?
Mammary glands
Sebaceous glands
Sweat glands
Hair
What type of secretion consists of disintegrated cells of the gland itself?
Holocrine
During what type of secretion are components synthesized and secreted as part of the cell but the cell remains functional?
Apocrine
What type of secretion is important for evaporative cooling, and involves components being synthesized and secreted as part of the cell but the cell remains functional? These follicles are activated during puberty.
Merocrine
Which type of milk secretion occurs when fat droplets are formed in cytoplasm, migrate to apical end of cell, and are pinched off?
Apocrine
Which type of milk secretion occurs when protein and lactose are packaged into secretory vesicles in Golgi apparatus and are released during exocytosis?
Merocrine
Describe the suspected evolution of the mammary gland in monotremes (prototherians):
- mammals that lay eggs
- most simple compared to marsupials and eutherians
- instead of nipples they have mammary patches which evolved from sweat glands
Describe the suspected evolution of the mammary gland in marsupials (metatherians):
- characterized by giving birth to relatively undeveloped young that then develop in mother’s pouch
- more complex than monotremes but less complex than eutherians
-varying number of teats within pouches depending on species
Describe the suspected evolution of the mammary gland in eutharians (placentals)
- undergo extensive development in the womb
- most complex mammary glands
- milk is richest in nutrients
The purpose of mammary glands is to _________ and its evolutionary precursor was likely ____________. The current hypothesis is that __________.
- supply nutrients and protective factors to support offspring and to pass on genes
- an early secretory skin gland
- the first secreted substance kept eggs moist and contained factors that aided development
What are the nutritive secretions of the mammary gland?
- milk
- colostrum
Malignancy depends on several phenomena. What are the major ones? Why do they matter?
- viruses and bacteria
- radiation
- genetics: mutations and DNA damage can disrupt normal functioning genes and can activate oncogenes or inactivate tumor suppressor genes
- diet
- hormones
What are the non-nutritive secretions of the mammary gland?
- Antibodies (immunoglobulins)
- lactoferrin: iron-binding protein
- lysozyme: enzyme that hydrolyzes bacterial walls
- lactoperoxidase: oxidizes bacterial components
- regulatory proteins like IGF-1 and leptin that aid in neonate development
What is angiogenesis? What is its role in cancer
- process by which new blood vessels are formed from pre-existing blood vessels
- essential for tumor growth, invasion and metastasis due to increased blood supply
Describe the role of estrogen in normal and malignant breast physiology.
- normal: produced by follicles of the ovary; stimulates lactogenesis (development and maintenance of mammary gland) by encouraging growth and branching of ductal system and proliferation of epithelial cells
- cancerous: stimulates proliferation of ER+ breast cancer cells