L01 - Intro to Endocrine System Flashcards
Name the endocrine glands
hypothalamus, pit gland, parathyroid, thyroid, thymus, pineal, adrenal, pancreas, ovary, testes
3 types of hormones receptor
steroid, tyrosine, G protein coupled
how does steroid hormone receptors work
hormone attaches to cell membrane, binds to cytoplasmic / nuclear receptor. this hormone receptor complex binds to hormone response element of DNA. Then gene transcription.
Tyrosine kinase receptors?
it is DIMERIZED
hormones bind to each receptor
receptor acts as enzyme to phosphorylate tyrosine kinase components of intracellular proteins
G protein coupled receptor?
hormone binds, secondary messenger activated.
IP3 and cAMP
phosphorylate intracellular regulatory proteins to influence cell activity
What are the two classes of hormone?
- Peptide Hormones
2. Steroid & Thyroid Hormones
Properties of steroid hormones
lipid soluble
bound to plasma protein in blood
bioactive when unbound
cam cross cell membrane and act on intracellular receptors
orally active
slow action onset, long plasma half life, long acting
Peptide Hormones properties
water sol not orally active need carrier protein to cross cell mem act on membrane bound receptors rapid onset short plasma half life and duration of action
what are the differences between steroid and peptide hormones
lipid vs water sol
oral activity
can it cross cell membrane
half life and duration of action
What type of hormone does the anterior pituitary secrete?
Stimulating (trophic) hormones
Anterior pituitary hormones: what are they and what do they do
STIMULATING TSH --> thyroid gland --> Thyroxine ACTH --> adrenal gland --> cortisol FSH --> ovary --> oestrogen LH --> ovary --> progesterone
What type of hormone does Hypothalamus release? what do they do?
Releasing hormones. control secretion of anterior pituitary
Hypothalamus hormones: what are they what they do
RELEASING TRH --> TSH CRH --> ACTH GnRH --> FSH GHRH --> Growth hormone
How is hormone secretion regulated?
usually negative feedback of the hormone decr. stim and releasing hormones
Consequence of negative feedback of hormones?
Cyclic variation of hormone conc
