Lactation, Galactorrhoea, Prolactinomas Flashcards
What is lactation?
- process of making breast milk
- process of secretion of milk by mammary glands
Where does the name galactorrhoea originate?
- galacto = greek for milk
- rheo = greek for flow
The name galactorrhoea originates from greek:
- galacto = greek for milk
- rheo = greek for flow
What does galactorrhoea mean?
- milky nipple discharge
- not related to normal milk production of breast-feeding
Label the image below using the labels here:
pectoralis major areola nipple adipose tissue lactiferous duct lobules and alveoli lactiferous sinus (ampulla)
1 = pectoralis major 2 = adipose tissue 3 = lobules and alveoli 4 = lactiferous sinus (ampulla) 5 = lactiferous duct 6 = nipple 7 = Areola
The lobules of the breast are adapted sweat glands that secrete milk and are composed of multiple alveoli. Using the labels below, label one of the alveoli in the image below using the provided labels:
- milk
- ductule
- milk secreting epithelial cells
- myoepithelial cells
1 - myoepithelial cells
2 - milk
3 - milk secreting epithelial cells
4 - ductule
Once the milk is produced by the epithelial cells of the alveoli, what is the flow form the alveoli to the nipples?
1 - epithelial cells, ductule, lactiferous sinus, lactiferous duct, nipple
2 - epithelial cells, lactiferous sinus, ductule, lactiferous duct, nipple
3 - epithelial cells, ductule, lactiferous duct, lactiferous sinus, nipple
4 - epithelial cells, lactiferous sinus, lactiferous duct, ductule, nipple
3 - epithelial cells, ductule, lactiferous duct, lactiferous sinus, nipple
In puberty there are 3 hormones that contribute to the development of breast tissue, specifically the alveolar and lobules, what are these 3 hormones?
1 - progesterone, estrogen, growth hormone
2 - oxytocin, estrogen, growth hormone
3 - progesterone, prolactin, growth hormone
4 - progesterone, estrogen, prolactin
1 - progesterone, estrogen, growth hormone
In puberty there are 3 hormones that contribute to the development of breast tissue, specifically the alveolar and lobules, progesterone, estrogen, growth hormone. Although these hormones are involved in the development of breast tissue, what do estrogen and progesterone inhibit during puberty?
- production of breast milk
In puberty there are 3 hormones that contribute to the development of breast tissue, specifically the alveolar and lobules:
1 - progesterone
2 - estrogen
3 - growth hormone
What growth factor do these hormones act through?
1 - vascular endothelial growth factor
2 - transforming growth factor
3 - RANK-L
4 - insulin growth factor-1 (IGF-1)
4 - insulin growth factor-1 (IGF-1)
In pregnancy there are 4 hormones that contribute to the development of breast tissue, specifically the alveolar and lobules, what are these 3 hormones?
1 - oestrogen, prolactin, hCG, hPL
2 - oestrogen, progesterone, hPL, prolactin
3 - oxytocin, progesterone, hPL, prolactin
4 - oestrogen, oxytocin, hCG, prolactin
hCG = human chorionic gonadotrophin hPL = human placental lactogen
2 - oestrogen, progesterone, hPL, prolactin
In pregnancy there are 4 hormones that contribute to the development of breast tissue, specifically the alveolar and lobules, oestrogen, progesterone, hPL, prolactin. Which of these is made by the placenta and which is secreted by the anterior pituitary gland?
hCG = human placental lactogen
- placenta = oestrogen, progesterone, hPL
- anterior pituitary = prolactin (when the placenta is delivered prolactin is dominant)
The image below shows histology tissue from 4 different time points for woman’s breast development. Label the image using the labels below to identify each time period:
pregnancy
virgin
involution
lactation
1 - virgin
2 - pregnancy (increased alveoli and lobules)
3 - lactation
4 - involution
Following breast feeding, breast tissue is said to involute, what does this mean?
- shrinking or return to normal size of an organ
- alveoli and lobular number reduce
In pregnancy there are 4 hormones that contribute to the development of breast tissue, specifically the alveolar and lobules:
1 = oestrogen 2 = progesterone 3 = human placental lactogen 4 = prolactin
Although this prepares the breasts for milk synthesis and secretion, during pregnancy they don’t normally secrete milk. High levels of one of these hormones produced by the placenta inhibit milk let down. Which hormone is responsible for this inhibition?
2 - progesterone
Once a baby is born and the placenta has been delivered the placenta based progesterone levels drop, allowing milk to flow. However, milk is not the first thing that is secreted. What is secreted?
1 - IgA antibodies
2 - colostrum
3 - fluid filled carbohydrates
3 - fluid filled protein
1 - colostrum
- high in protein, carbs, immune cells (IgA) and low in fat
Once a baby is born and the placenta has been delivered the placenta based progesterone levels drop, allowing milk to flow. However, the first thing secreted is colostrum, which is high in protein, immune cells and low in fat. In addition to nourishing the baby, what does colostrum do to the GIT?
- acts as a laxative
- helps baby pass the first poo called meconium
What is prolactin and where is it synthesised and secreted?
- hormone produced by anterior pituitary gland
- produced by lactotrophs cells
Prolactin is a hormone synthesised and secreted by the anterior pituitary gland, produced by lactotrophs cells. What is the function of prolactin?
1 - stimulates breast tissue to synthesise and secrete colostrum
2 - stimulates breast tissue to synthesise and secrete IgA antibodies
3 - stimulates breast tissue to synthesise and secrete breast milk
4 - stimulates breast tissue to help deliver placenta
3 - stimulates breast tissue to synthesise and secrete breast milk
What is oxytocin and where is it synthesised and secreted?
- peptide hormone synthesised and secreted by posterior pituitary gland
Oxytocin is a peptide hormone synthesised and secreted by posterior pituitary gland. Oxytocin has 2 MAIN key functions, what are they?
1 - breasts to secrete milk and help mum bond with baby
2 - breasts to secrete milk and uterine contractions during labour
3 - breasts to secrete milk and help mum feel happy
4 - uterine contractions during labour and help mum bond with baby
2 - breasts to secrete milk and uterine contractions during labour
- signals myoepithelial cells of breast glands to contract and secrete milk
- part of positive feedback loop to trigger uterus contractions in labour
In pregnancy there are 4 hormones that contribute to the development of breast tissue, specifically the alveolar and lobules:
1 = oestrogen 2 = progesterone 3 = human chorionic somatomammotropin 4 = prolactin
What is the role of estrogen and progesterone on the breasts during pregnancy?
- physical development of the breast
- inhibition of breast milk secretion (mainly progesterone)
In the first 1-7 days following birth the breast secrete copious amounts of milk after colostrum. What hormones are important in the the secretion of this breast milk, ensuring adequate supply of amino acids, fatty acids, glucose, and calcium (not including prolactin and oxytocin)?
1 - growth hormone, parathyroid hormone,insulin, estrogen
2 - growth hormone, cortisol, parathyroid hormone,andestrogen
3 - growth hormone, cortisol, parathyroid hormone,andinsulin
4 - growth hormone, FSH, parathyroid hormone,andinsulin
3 - growth hormone, cortisol, parathyroid hormone,andinsulin
Following birth and the delivery of the placenta there is a substantial drop in estrogen and progesterone. Which then results in an increase in what key hormone secreted by the anterior pituitary gland?
- prolactin
Following birth and the delivery of the placenta there is a substantial drop in estrogen and progesterone. Which then results in an increase in prolactin secreted by the anterior pituitary gland. What normal response can cause a positive feedback loop to stimulate further secretion of prolactin and therefore more breast milk synthesis and secretion?
- breastfeeding
- suckling provides tactile stimulation to hypothalamus
- hypothalamus responds with increased prolactin
Following birth and the delivery of the placenta there is a substantial drop in estrogen and progesterone. Which then results in an increase in prolactin secreted by the anterior pituitary gland, which can be further increased through breastfeeding. Prolactin also has an inhibitory effect on the hypothalamus causing the reduction in the secretion of what 3 hormones that are involved in the menstrual cycle?
1 - gonadotrophin releasing hormone (GnRH) inhibited from hypothalamus
2 - no GnRH means no LH and FSH secreted from pituitary gland
Prolactin increases following birth to synthesise and secrete breast milk. This results in inhibition of:
1 - gonadotrophin releasing hormone (GnRH) inhibited
2 - no GnRH means no LH and FSH
What effect does this have on the ovaries and the menstrual cycle?
- no follicular development and maturation
- no ovulation, so generally no periods when breast feeding
- 100% breast feeding is a form of contraception
Prolactin increases following birth to synthesise and secrete breast milk. This results in inhibition of gonadotrophin releasing hormone (GnRH), LH and FSH, so no menstrual cycle. Prior to pregnancy dopamine, also called prolactin inhibitory hormone is able to inhibit prolactin. However, at pregnancy this changes. What 3 other hormones are secreted that have a stimulatory effect on prolactin secretions?
1 - serotonin, oxytocin, progesterone
2 - serotonin, oxytocin, thyrotropin-releasing hormone
3 - progesterone, oxytocin, thyrotropin-releasing hormone
4 - serotonin, progesterone, thyrotropin-releasing hormone
2 - serotonin, oxytocin, thyrotropin-releasing hormone
In a woman who is not pregnant, the release of prolactin is inhibited. What causes this inhibition?
- dopamine also called prolactin inhibiting factor
- secreted by the hypothalamus
In a woman who is not pregnant, the release of prolactin is inhibited by dopamine also called prolactin inhibiting factor. This is secreted by what cell nucleus in the hypothalamus?
- arcuate nucleus
In a woman who is not pregnant, the release of prolactin is inhibited by dopamine also called prolactin inhibiting factor. This is secreted by the arcuate nucleus in the hypothalamus. In addition to inhibiting prolactin, what other hormone is dopamine able to inhibit the release of from the hypothalamus that is increased when breastfeeding?
1 - thyroid stimulating hormone
2 - gonadotropin releasing hormone
3 - corticosteroid releasing hormone
4 - thyrotropin-releasing hormone
4 - thyrotropin-releasing hormone
What is the process called milk let down, also known as milk ejection?
1 - suckling causes progesterone and estrogen release, breasts fill and repeats
2 - suckling causes oxytocin and estrogen release, breasts fill and repeats
3 - suckling causes prolactin and estrogen release, breasts fill and repeats
4 - suckling causes oxytocin and prolactin release, breasts fill and repeats
4 - suckling causes oxytocin and prolactin release, breasts fill and repeats
- suckling triggers hypothalamus
- pituitary releases prolactin and oxytocin
- breasts fill up (prolactin) and myoepithelial cells contract (oxytocin)
- baby suckles on breasts causes the secretion of breast milk from the breast
The figure below shows the levels of 3 key hormones following parturition (time following birth). Use the labels below to label the 3 key hormones:
- progesterone
- estrogen
- prolactin
1 - estrogen
2 - progesterone
3 - prolactin (goes up and down during breastfeeding)
What 2 key sugars are present in breast milk?
1 - lactose and oligosaccharides
2 - glucose and lactose
3 - disaccharides and lactose
4 - lactose and disaccharides
1 - lactose and oligosaccharides
Galactorrhoea refers to milky nipple discharge that is not related to normal milk production of breast-feeding. High levels of which hormone as associated with galactorrhoea?
- prolactin, also called hyperprolactinaemia
High levels of prolactin called hyperprolactinaemia is a common cause of galactorrhea. What are the 4 key presentations that are common in women who have hyperprolactinaemia?
1 - amenorrhoea, galactorrhea, subfertility, hypopituitarism
2 - hyperthyroidism, galactorrhea, subfertility, hypopituitarism
3 - amenorrhoea, galactorrhea, increased fertility, hyperpituitarism
4 - amenorrhoea, lack of oxytocin, subfertility, hypopituitarism
1 - amenorrhoea, galactorrhea, subfertility, hypopituitarism
- galactorrhea (non-pregnancy related milky discharge) due to increased prolactin
- amenorrhoea (absence of bleeding) due to low LF and FSH, inhibited by high prolactin
- hypopituitarism
High levels of prolactin called hyperprolactinaemia is a common cause of galactorrhea. What are the 5 key presentations that are common in men who may have hyperprolactinaemia?
- reduced libido
- visual symptoms
- headaches
- hypopituitarism
- gynaecomastia
High levels of prolactin called hyperprolactinaemia is a common cause of galactorrhea. This can cause menorrhoea, galactorrhea, subfertility, hypopituitarism. However, if there is an issue with the anterior pituitary gland that is causing hyperprolactinaemia, what dangerous effect could this also have?
1 - reduced all other hormones secreted by anterior pituitary gland
2 - increase all other hormones secreted by anterior pituitary gland
3 - compress on the optic chiasm causing sight changes
4 - compress the hypophyseal portal system causing pituitary ischaemia
3 - compress on the optic chiasm causing sight changes
Prolactin increases following birth to synthesise and secrete breast milk. This results in inhibition of:
1 - gonadotrophin releasing hormone (GnRH) inhibited
2 - no GnRH means no LH and FSH (reducing estrogen production)
This causes no follicular development and maturation or no ovulation, so generally no periods when breast feeding. In a patient with hyperprolactinaemia, this may further decrease levels estrogen which can have what affect on the bones of women?
- increased risk of osteomalacia or osteoporosis
- estrogen inhibits osteoclast
- low estrogen = high osteoclasts (dissolve bone)
What affect can hyperprolactinaemia have on the testes?
- increased prolactin inhibits GnRH
- low GnRH = low testosterone
- low testosterone = reduced spermatogenesis
Hyperprolactinaemia can be causes by a pituitary tumour. What effect can this have on the eyes?
- tumour may press on the optic chiasm
- causes bitemporal hemianopia and press on meninges causing pain
Hyperprolactinaemia can commonly be caused by what 2 physiological processes?
1 - pregnancy (continued milk production for up to 2 years)
2 - parturition (giving birth)
Hyperprolactinaemia can commonly be caused by what 2 hypothalamic pituitary diseases?
1 - micro / macroPRLoma (varying size of tumour on pituitary gland
2 - non-functioning adenoma
Hyperprolactinaemia can commonly be caused by what 2 day to day activities?
1 - adverse events of drugs
2 - stress/anxiety
Hyperprolactinaemia can commonly be caused by hypothyroidism, why?
- hypothalamus increases secretion of thyrotropin releasing hormone (TRH)
- TRH stimulates release of prolactin
- low TSH and T3 and T4 = no negative feedback loop
- hypothalamus increases TRH secretion
What is a prolactinoma?
1 - malignant tumour on pituitary gland
2 - adenoma (non-malignant tumour) on pituitary gland
3 - adenoma on the hypothalamus
4 - damage to the anterior pituitary gland
2 - adenoma (non-malignant tumour) on pituitary gland
- causes excessive levels of prolactin to be released
In Addisons disease, which is essentially hypoadrenalism, there is low levels of cortisol. How can this lead to hyperprolactinaemia?
- high cortisol inhibits the release of prolactin
- low cortisol = high prolactin
Antidepressants, antipsychotics and drugs used for nausea & vertigo (Phenothiazines, Metoclopramide and Domperidone) can also cause Hyperprolactinaemia. How does this occur?
- dopamine, also called prolactin inhibitory hormone, inhibits prolactin secretion
- drugs act as dopamine antagonists, meaning less dopamine and more serotonin
- less dopamine = increased prolactin release
- more serotonin = increased prolactin release
What blood tests can be performed in an attempt to identify the cause of hyperprolactinaemia?
- pregnancy test
- renal function (U&E, creatinine)
- liver function tests
- thyroid function
- prolactin levels
- hormones (LH, FSH, GH, IGF1, oestradiol and testosterone)
Why would an MRI be useful in an attempt to identify the cause of hyperprolactinaemia?
- identify if a tumour is present on pituitary gland
Although there are a number of things to consider when treating hyperprolactinaemia, what is the main aim of this treatment for most women?
1 - restore fertility
2 - stop galactorrhea
3 - restore regular cycles and libido (reduce osteoporosis)
4 - shrink tumour
1 - restore fertility
- this will coincide with a return to menstrual cycles
What are the 4 key aims when treating hyperprolactinaemia?
- restore fertility (MAIN AIM)
- stop galactorrhea
- restore regular cycles and libido (reduce osteoporosis)
- shrink tumour
A pituitary adenoma can be divided into:
- Functional adenoma or prolactinoma
- Non functional adenoma (NFA)
What is a functional adenoma or prolactinoma?
- when a tumour causes excess production of one or more hormones
- prolactinoma is an example where a tumour causes overproduces of prolactin
- acromegaly (adults), gigantism (child), causes an excess growth hormone secretion
What is the medical treatment for prolactinoma?
- dopaminergic drugs = Cabergoline and Bromocriptine
- same effects as dopamine so able to inhibit prolactin
What is a nonfunctioning pituitary adenoma?
- a benign growth in the pituitary gland that does not produce any excessive hormone into the blood and is not cancerous
A nonfunctioning pituitary adenoma is a benign growth in the pituitary gland that does not produce any excessive hormone into the blood and is not cancerous. How is this treated?
- surgery and radiotherapy
- patient could lose pituitary function during surgery
