Endocrinology: Pregnancy Hormones Flashcards
Differentiate between endocrine, paracrine and autocrine secretion.
Endocrine: released and acts on far away target
Paracrine: acts on nearby cell
Autocrine: acts on same cell
How do endocrine hormones travel to target cells?
through the blood
Differentiate the types of endocrine hormones
Amino acid based: proteins and peptides, can be made and stored when needed, hydrophilic, bind to receptors outside of cell
Steroids: synthesised from cholesterol, right combination of enzymes present to turn into right steroid, hydrophobic, bind to receptor inside cell
Define tropic hormones
act on other endocrine glands to induce secretion of second hormone
Describe the 2 types of hormone regulation
negative feedback: hormone binds to receptor which stops production of hormone
positive feedback: stimulates further production of hormone
what hormones does the posterior pituitary gland release and where are they made?
releases oxytocin and ADH, made in the paraventricular nucleus of hypothalamus
What effects can syntocin have
excessive contractions and impacts on fetal HR
Describe the positive feedback loop involving the cervix and oxytocin
stretching of cervix causes release of more oxytocin which causes uterus contractions and more stretching = more oxytocin
What enzyme inhibits ADH
vasopressinase
What causes release of ADH
osmolality levels, Low BP, pain, drugs
What does ADH regulate in pregnancy?
fluid homeostasis and expansion
What occurs if there is a dysregulation between vasopressinase and ADH and what can this result in?
Diabetes insipidus -> dehydration, fetal loss
What are the three main mechanisms of oral contraceptives?
stops ovulation by preventing surge in LH, thickens cervical mucous to stop sperm implantation, stops endo thickening
Where is prolactin secreted and what is it triggered by?
Lactotrophs secrete prolactin from ant pit in response to low prolactin inhibiting hormone (dopamine)
What effects does prolactin have in pregnancy
stimulates milk production, breast swelling, changes body composition and metabolic processes
list the 3 main adrenal hormones
glucocorticoids (cortisol), mineralocorticoids (aldosterone), androgens (DHEA)
What is a main function of DHEA
regulates feminisation/masculisation of fetus
What type of receptors do steroid hormones bind to?
nuclear or cytoplasmic
