Flashcards in Endocrine Deck (26)
Direct signalling involves?
Indirect signalling involves?
Functional classifications of chemical messengers?
Paracrines, autocrines, hormones, cytokines, neurohormones, neurotransmitters
Chemical structure determines mechanisms of..?
synthesis, release, transport, signal transduction
Hydrophobic/lipophilic chemical messengers?
Steroids (androgens, oestrogens) & eicosanoids (PGE's)
Hydrophilic/lipophobic chemical messengers?
AA derivatives (biogenic amines), proteins (peptides), AA's
What are the 4 types of receptors?
ligand-gated ion channel, receptor-enzyme, G-protein-coupled receptor, intracellular receptor
Define antagonistic hormone interaction
hormones oppose each other
Define synergistic hormone interaction
effect is additive
Define permissive hormone interaction
one hormone needed for other to produce an effect eg. adrenaline + thyroid hormone
Define intergrative hormone interaction
additive (same response via different signalling)
Primary organs that secrete hormones?
hypothalamus, pituitary, pineal, thyroid, pancreas, gonads, adrenal
Secondary organs that secrete hormones?
Heart, liver, stomach, SI, skin, kidneys
What are the 6 hormones produced by the anterior pituitary and where do they act?
TSH (thyroid), PRL (mammary gland), ACTH (adrenal gland), GH (adipose, muscle, bone), FSH & LH (gonads), MSH (melanocytes)
Give examples of pulsatile, circadian and episodic hormones
LH, melatonin, prolactin
Give examples of posterior pituitary hormones and where they act
vasopressin/ADH (kidneys & arterioles - vasoconstriction), oxytocin (uterus - contractions & mammary glands - milk production)
What are the regions of the adrenal gland?
Cortex (zona glomerulosa, zona fasciculata, zona reticularis) & medulla (adrenal medulla)
Which types of hormones are released by the adrenal cortex?
Mineralocorticoids (aldosterone), Glucocorticoids (cortisol), & sex hormones (androgens)
Which types of hormones are released by the adrenal medulla?
Catecholamines (adrenaline & NA)
Actions of mineralocorticoid; aldosterone and where it acts?
Long term electrolyte & BP homeostasis. Action in kidneys to retain H2O & Na -> increase ECF -> blood volume -> BP
Actions of glucocorticoid; cortisol and where it acts?
Increases glucose & AA's in blood, adipose (increase lipolysis), muscles & other tissue (protein catabolism), liver (gluconeogenesis)
Actions of catecholamine; adrenaline and where it acts?
Increase HR, contractility, BP (heart), dilation of pupils & airways (eyes & lungs), lipolysis (adipose), gluconeogenesis & glycogenolysis (liver)
Actions of insulin & sites of action?
glucose uptake, storage as glycogen & triglycerides, decrease blood glucose, FA's, AA's, protein synthesis, increase fuel storage
Actions of glucagon & sites of action?
glycogenolysis, gluconeogenesis, ketone synthesis, protein breakdown (liver), lipolysis (adipose)
2 thyroid hormones and their actions?
T3 & T4 (3 or 4 iodine molecules) - increase MBR, decreases body weight, increase cardiac output, increased resp depth & rate, increased growth & CNS dev., influences skin & hair growth