endocrine system Flashcards
what is hypersecretion?
too much hormone secreted
what is hyposecretion?
too little hormone secreted
hormones are secreted by what?
specialised ductless glands or neurones
The 2 divisions of the endocrine system?
Central system
Peripheral system
3 parts of the central endocrine system?
hypothalamus
pituitary gland
pineal gland
4 parts of the peripheral endocrine system?
thyroid glands
adrenal glands
endocrine pancreas
parathyroid glands
example of amines and amino acid hormones?
NA (noradrenaline) DA (dopamine) T4 (thyroxine)
examples of polypeptide, protein and glycoprotein hormones?
TRH ADH GH FSH
examples of steroid hormones?
cortisol, testosterone, estradiol (estrogen), progesterone
2 pathways of hormone synthesis?
vesicle-mediated pathway
non-vesicle mediated pathway
where are vesicle-mediated synthesised?
in rough endoplasmic reticulum
packaged in vesicle
where are non-vesicle mediated synthesised?
in smooth endoplasmic reticulum
directly released
which class of hormones are free & unbound?
amine/amino acid/peptide hormones
which class of hormones are protein-career bound?
steroid and thyroid hormones
types of pattern of secretion?
pulsatile/cyclical
diurnal/circadian rhythm
2 types of hormonal receptors?
cell surface
intracellular or nuclear
2 forms of abnormal target cell responsiveness?
receptor down regulation (hypo responsiveness)
receptor up regulation (hyper responsiveness)
where are hypothalamus and pituitary located?
in the diencephalon
the 2 lobes of the pituitary glands?
anterior (adenohypophysis)
posterior (neurohypophysis)
what happens at anterior pituitary?
6 major hormones secreted and released
what happens at posterior pituitary?
2 hormones stored and released
what does the hypothalamus act as?
neuroendocrine transducer
types of anterior pituitary hormones?
GH, FSH, LH, PRL, TSH, ACTH
types of posterior pituitary hormones?
vasopressin (ADH) , oxytocin
what hormone does pineal gland secrete?
melatonin
what stimulates melatonin production?
suprachiasmatic nucleus SCN
‘biological clock’
the 2 distinct cell types of the thyroid gland?
follicular cells
parafollicular/ C cells
what do the follicular cells (major cells of thyroid gland) secrete?
2 iodine containing hormones
thyroxine (T4)
T3
what do C cells secrete?
calcitonin
functions of thyroid hormone?
normal growth and CNS development
metabolic rate and heat production
intermediary metabolism
sympathetic activity
the 2 distinct secretory organs of the adrenal glands?
outer adrenal cortex
inner adrenal medulla
what does the outer cortex secrete?
3 types of steroid hormones
mineralocorticoids
glucocorticoids
sex hormones
what does the inner medulla secrete?
catecholamines (dopamine, adrenaline, noradrenaline)
example of a mineralocorticoid and what it does?
aldosterone
-maintain Na/K balance and extracellular fluid volume
example of a glucocorticoid and what it does?
cortisol
- regulation of metabolism
- adaptation to stress
- anti-inflammatory & immunosuppressive
example of a sex hormone and what it does?
DHEA
- minor effects on reproductive function
examples of catecholamines and function?
adrenaline, noradrenaline, dopamine
- fight or flight responses
3 types of secretory cells of endocrine pancreas?
alpha cells - glucagon
beta cells - insulin
delta cells - somatostatin
