intro to endocrine system Flashcards
describe endocrine transmission?
chemicals are secreted into the bloodstream then sent to parts of the body
give examples of some endocrine glands
hypothalamus, pituitary, thyroid, parathyroid, pancreas, adrenal, endocrine cells in GI, gonodads, placenta, pineal gland, thymus
what are the 2 classifications of hormones?
- steroids
- non-steroids
steroid hormones are based on which type of structure?
cholesterol ring structure
give examples of steroid hormones?
- cortisol
- aldosterone
- testorsterone
- progesterone
- oestrogen
non-steroid hormones can be subdivide into 3 classes, what are these ?
- amino acid dervatives
- peptides
- glycoproteins
give examples of non-steroidal amino acid derivatives (amines)
- adrenaline
- noradrenaline
- melatonin
- thyroxine
give examples of short chain peptide hormones?
- ADH
- ANH
- ocytocin
- somatostatin
- melanocyte stimulating hormone
give examples of long chain peptide hormones (proteins)?
- growth hormone
- prolactin
- parathyroid hormone
- calcitonin
- insulin
- glucagon
describe the structure of a non-steroidal glycoprotein hormone
carbohydrate group attached to amino acid
give examples of non-steroidal glycoprotein hormones
- FSH
- LH
- thyroid stimulating hormone
- gonadotrophin
what are pro-hormones?
peptide hormones produced in inactive precursor form
where are pro-hormones packaged and converted to active hormones?
golgi apparatus
which word describes a hormone which has effect only in the vicinity of the gland secreting it?
paracrine
give examples of paracrine hormones (local tissue hormones)?
- prostaglandins
- leukotrienes
- thromoxanes
which class of hormones act via 2nd messenger systems?
non-steroidal hormones
name 2 common 2nd messenger systems?
- cAMP
- calcium
which feature of steroid hormones allow them to pass through the cell membrane to reach intracellular receptors?
they are lipophilic
what type of feedback are most hormone systems regulated by?
negative feedback
how does negative feedback work?
some function of output mechanism is fed back in order to reduce output
what is excess hormone secretion known as?
hypersecretion
what is decreased hormone secretion known as?
hyposecretion
what does up regulation refer to?
- increase in sensitivity
- more receptors
what does down regulation refer to?
- decrease in sensitivity
- fewer receptors
what condition is up regulation of hormones associated with?
hyper secretion
what condition is down regulation of hormones associated with?
hypo secretion
