hormones Flashcards
(47 cards)
how do autocrine, paracrine and endocrine differ?
depends on the distanc they travel and where they act (self acting, nearby tissue or far away)
what is the main mechanism for hormone control (the very basis if homeostasis?)
negative feedbck loopsss (and some postive)
examples of peptide hormones? how do they act?
Parathyroid hormone, growth hormone, oxytocin, ADH
> secondary messenger, rapid but shorterm
examples of steroid hormones? how do they act?
Corsitol and sex hormones
nucleus receptor to affect ranscription so slow acting. Cholestrol derivative
how many hormones does posterior pituitary release? what are they?
The posterior pituitary releases only 2 hormones and they are oxytocin and ADH.
conncected to hypothalamus by nerve fibres
tyrosine residue hormones examples
T4 and t3 - steroid like behavior
(nor) adrenalin - peptide like behavior
Define tropic and non tropic hormone
FLAT PEG
tropic hormones exert effect on other endocrine glands - these glands cannot function without stimulation from anterior pituitary
non tropic hormones have a direct effect on tissues
What is the name of the disorder that causes enlarged hands, feet, tongue, lips?
acromegly - due to Growth hormone excess in ADULTHOOD
in children as the growth plates are open you get gigantism
Where will the optic chiasma be located with relation to the anterior pituitary?
Same side as the anterior pituitary
What is the effect of ADH on urine?
more ADH, the more concentrated urine as there more aquaporins, increased water reabsorption and therefore more concentrated urine
what is the relationship betwen growth hormone and glucose
acts to CONSERVE glucose for CNS
> blocks insulin action
>also protects agaisnt hypoglycaemia
so those with excess GH can be diabetic due to this anti insulin effect
actions of growth hormone
increased lipolysis, more protein synthesis (LEAN MUSCLE), and increased gluconeogeneis
how does Insulin-like-Growth Factor (IGF) work?
affects open growth plates to stimulate skeletal and soft tissue growth
when plates fuse this leads to IGF ceasing/ inabily to maintain lean muscle (somatopause)
how can you distingush between pituitary dwarfism and other types of dwarfism>
pituitary dwarfism has normal body proportions! as both the bone and soft tissue have slow growth
how to treat hypothyroidism
levythyroxin - artificial t4
fun fact about t3
more potent than t4 but less secreted
hyperthyroidisim characterized by … levels of hormone
and then thats vice versa for hypo
low TSH and TRH (brain) but high thyroxine levels
- so clearly the negative feedback loop is working as you get low levels from the brain but the CAUSE of it is due to ‘mimicry antibodies’ so the t4/t3 levels stay high
If a patient has low T3 and T4 how will this affect there TSH levels?
thyroid stimulating hormone levels will be high (as well as TRH levels)
location of adrenal glands
sit above the kidney enclosed by fibrous capsule and fat with medulla and cortex
adrenal medulla hormones
(nor)adrenaline which is a catelcholamine
but it is NOT under hormonal control!
»short term stress
adrenal cortex hormones
> > long term stresses`
mineralcorticoid - zona glomerulosa.
glucocorticoid - zona fasciculata
androgens! - zona reticularis
Which disease is caused by deficits in glucocorticoids and mineralocorticoids that causes progressive weakness, weight loss, pigmentation to skin and muscosal membranes?
Addisons disease - automimmune and insufficient ADRENAL CORTEX hormones
what steroid hormone does the Zona Fasciculata release?
Glucocorticoid (Cortisol)
what are the effects of aldosterone?
mineralcorticoid : conserves body sodium,stimulate reabsorption of sodium and controls ECF volume
> regulated by renin-angiotensin system, not the hypothalamus!
