Endocrine System Flashcards
Peptide Hormones
Made up of amino acids, Adh, insulin. Activated in golgi, charged cant pass through membranes so need a receptor. Peptide hormone= first messenter, second signal due to hormone is second messenger
Common second messengers
cAMP, IP3, Calcium
Effects of peptide hormones
rapid but short lived. Gnerally water soluble, peptide hormones do not require carriers
Steroid Hormones
From cholesterol, produced by gonads and adrenal cortex. Nonpolar, can cross cell membrane . Receptors usually in cytosol or nucleus. Upon binding, complex undergoes configuational change can bind DNA.
Steroid Hormone Effect
Slower but longer lived than peptide hormones because they alter the amount of mRNA and protein present in the cell. They are not water soluble so they need a carrier to travel around the body
Amino Acid Hormones
Epi, norepi, triiodothyronine and thyroxine. Catecholamines (epi and nor epi are going to bind to G protein) thyroid hormones will bind intracellularly.
Direct hormones
secreted and act directly on a target tissue
triphic hormones
req intermediary usually originate in the brain and anterior pituitary.
Hypothalamus
bridge between endocrine and nervous system. linked inextricably to the pituitary.
Released by Hypo (A) Released by Anterior Pit (B)
A- Gonadotropin releasing hormone
B FSH and LH
Growth hormone releasing hormone is released by hypothalamus
triggers GH to be secreted by A. Pit.
Thyroid releasing hormone secreted by hypothalamus triggers release of
TSH thyroid stimulating hormone in A. Pit.
Corticotropin releasing factor is secreted by hypothalamus. this stimulates the anterior pituitary to relase
Adrenocorticotropic hormone ACTH
Prolactin Inhibiting Factor released by hypothalamus stimulates
a decrease in prolactin secretion by anterior pituitary
Interactions of hypothalamus and posterior pituitary
Neurons of pituitary stalk stimulate relase of oxytocin and ADH.
oxytocin
stimulates uterine contractions during labor and milk production
ADH
vaso pression- increases reabsorption of water in cd. is released when there is increased plasma osmolarity or increased solute concentration in the blood
Paracrine
Regional extracellular fluid (cells communicate through ) cells are in proximity or space between
How does insulin function
rise in blood sugar triggers release of insulin to stimulate glucose uptake by tissues and decrease blood sugar.
glucagon
low blood sugar stimulates relase of glucagon and then glycogenolysis to increase blood sugar
insulin is released by
pancreatic beta cells
glucagon is released by
alpha pancreatic cells
Type I diabetes
destroyed beta cells of islets of langerhan
Type II diabetes
Insensitive to INsulin.
Epinephrine
Catecolamine released from adrenal medulla , sympathetic nervous system, promotes glycogenolysis and fatty acid release from adipose tissue
Thyroxine T4
T3 is active version. All about the number of iodine. Promotoes glycogenolysis and sugar absorbtion by intestines
Calcium is controlled by thyroid and parathyroid
Thyroid produces calcitonin. Parathyroids produce parathyroid hormone.
Aldosterone
increases blood pressure
Angiotensinogen is secreted by the
liver
Renin is secreted by the
kidney
Renin cleaves angiotensionogen
angiotensin I
Angiotensin I is made into angiotensin 2 via
ACE
What stimulates the release of aldosterone
angiotensin II
Aldosterone allows the body to
reabsorb Na+ water follows and this increases bp
Tropic hormones of the anterior pituitary
FLAT. FSH, LH, ACTH, and TSH
Direct hormones of anterior pituitary
PEG- Prolactin, Endorphins, GH
FSH leads to
estrogen, essential for female development and reproduction
LH leads to
progesterone, helps the uterus develop for fertility (endometrium) when LH spikes it causes ovulation.
Somatostatin
Inhibitor of both insulin and glucagon secretion. stimulated by increase blood glucose and amino acids. produced by hypothalamus, function is to decrease growth hormone secretion
Kidneys produce
erythropoietin
Heart
atrial natriuretic peptide to regulate salt and water balance. when cells in atria are stretched from increased blood volume, anp is relased. it promotes sodium excretion so it increased urine volume.
