Endocrine System Flashcards
Amino acid based hormones are known as what ?
Peptide hormones
- charged & cannot pass through membrane
- Effects quick but short lived
- Water soluble = travel through bloodstream freely
- in or -ine
What are some common secondary messengers ?
cAMP, IP3 (inositol triphosphate), & Ca2+
What type of hormones are derived from cholesterol and are produced mainly by the adrenal cortex & gonads ?
Steroid hormones
- Easily cross cell membrane
- Slower but longer lived effects (gene regulation)
- one, -ol, -oid
Pairing of 2 receptor-hormone complexes is known as ?
Dimerization
Amino acid hormones w/ some modifications are known as ?
Amino acid-derivative hormones
The blood vessel system that connects the hypothalamus to the anterior pituitary is known as ?
Hypophyseal portal system
What tropic hormones are released from the hypothalamus to the anterior pituitary, & which hormones are released from the AP as a result ?
GnRH---->FSH & LH GHRH----->GH TRH----->TSH CRF----->ACTH *PIF----->decreased prolactin secretion
How does the hypothalamus interact with the posterior pituitary ?
Neurons in HT send axons down PP stalk directly into the PP
What 2 hormones does the posterior pituitary store from the HT ?
Oxytocin: stimulates contractions of the uterine lining during labor, aids in milk production of mammary glands (lactation) Antidiuretic hormone (vasopressin): reabsorption of H2O in collecting ducts of the kidneys
The hormone that is released by the AP & is responsible for milk production in the mammary glands is known as ?
Prolactin
*release of dopamine (PIF) causes decreased secretion
Hormones that decrease pain perception are known as ?
Endorphins (naturally occuring painkillers)
Hormone that promotes the growth of bone & muscle is known as ?
GH
What is ADH secreted in response to ?
Low blood volume or high blood osmolarity
*results in increased blood volume & pressure
What are the 2 major functions of the thyroid ?
- setting basal metabolic rate: mediated by T3 & T4 (iodination of amino acid tyrosine)
- promoting Ca2+ homeostasis: calcitonin (decreases Ca2+ levels in plasma)
A deficiency in iodine or inflammation of the thyroid may lead to what ?
Hypothyroidism
What is the hormone produced by the parathyroid glands & what is its function ?
PTH functions as antagonist to calcitonin
- raises Ca2+ levels in plasma
- promotes phosphorous homeostasis
- activates vitamin D: required for absorption of Ca2+ & P in the gut
What type of hormones does the adrenal cortex secrete ?
Corticosteroids
What are the different type of corticosteroids ?
Glucocorticoids: regulate glucose levels (cortisol & cortisone)–>raise blood glucose by increasing gluconeogenesis & decreasing protein synthesis
Mineralocorticoids: regulate salt & H20 homeostasis (kidneys)
-aldosterone: increases Na+ reabsorption in distal convoluted tubule & collecting duct of nephron
Cortical sex hormones: androgens & estrogens
Aldosterone is primarily under the control of which system ?
Renin-angiotensin-aldosterone:
- Decreased BP—>juxtaglomerular cells secrete renin
- Renin cleaves inactive angiotensinogen to active form—> angiotensin I
- Ang I converted to ang II via enzyme (ACE) in lungs
- Ang II—->adrenal cortex—-> aldosterone
Which hormones are the adrenal medulla responsible for secreting ?
Epinephrine & norepinephrine
*Catecholamines
Small clusters of hormone-producing cells in the pancreas are known as ?
islets of Langerhans:
alpha: glucagon: secreted when glucose levels are low
beta: insulin: secreted when glucose levels are high
delta: somatostatin: inhibits both glucagon & insulin secretion
