Intro Flashcards
Classic endocrine glands
- Pituitary (anterior and posterior)
- Thyroid
- Parathyroid
- Adrenal
- Pancreas (islets)
- Gonads
Hormones secreted by hypothalamus
- TRH
- CRH
- GnRH
- GHRH
- Somatostatin
- Dopamine
Hormones secreted by anterior pituitary
- TSH
- FSH
- LH
- ACTH
- MSH
- GH
- Prolactin
Hormones secreted by posterior pituitary
- Oxytocin
- ADH
Hormones secreted by thyroid
- T3
- T4
- Calcitonin
Hormones secreted by parathyroid
-PTH
Hormones secreted by pancreas
- Insulin
- Glucagon
Hormones secreted by adrenal medulla
- Norepi
- Epi
Hormones secreted by kidney
- Renin
- 1,25-Dihydroxycholecalciferol
Hormones secreted by adrenal cortex
- Cortisol
- Aldosterone
- Adrenal androgens
Where do peptide and amino acid hormones bind?
Receptors on the membrane. They are hydrophilic and can’t cross the cell membrane.
Where do steroid hormones bind?
Enter the cell and activate nuclear or cytoplasmic receptors.
Characteristics of steroid hormones
- No storage pools
- Diffuse through cell membrane
- Receptor in cytoplasm or nucleus
- Regulate gene transcription
- Respond in hours to days
Characteristics of peptide-amine hormones
- Storage pools in secretory vesicles
- Receptor on cell membrane
- Signal transduction cascade affects variety of processes
- Respond in seconds to minutes
- NOTE T3 and T4 can directly enter a cell
Pseudohypoparathyroidism
- Molecular alterations in G proteins affect certain signaling systems
- Abnormality in subunit alphaS in a heterotrimeric G protein
- Impairment of PTH to regulate body calcium and phosphorus homeostasis
- Low serum Ca and high serum phosphate levels
- Have increased levels of PTH (it’s just not working correctly)
Where does the pituitary gland lie?
Sella turcica in the base of the brain
Anterior pituitary
- Adenohypophysis
- Receives venus blood carrying neuropeptides from the hypothalamus and pituitary stalk
- Hypophyseal portal circulation with pituitary
- Produces protein and glycoprotein hormones
Posterior pituitary
- Neurohypophysis
- Neural connections from hypothalamus (paraventricular nucleus and supraoptic nucleus)
- Arterial blood
- Produces ADH and oxytocin
Release of growth hormone
- Hypothalamus releases GHRH (inhibited by somatostatin)
- Affects somatotroph in anterior pituitary
- GH released
Release of TSH
- Hypothal releases TRH to thyrotroph in anterior pit
- TSH released to stimulate thyroid
Release of ACTH
- Hypothal releases CRH to cortiocotrophs in ant pit
- ACTH released to stimulate adrenal cortex
Release of FSH and LH
- Hypothal releases GnRH to gonadotrophs in ant pit
- FSH and LH released
Prolactin and dopamine relationship
- Prolactin under tonic inhibitory control by dopamine
- TRH stimulates prolactin release
- If pituitary stalk is severed prolactin will increase
- Will also increase with a D2 receptor antagonist
