Midterm 2 - Endocrine Major Glands and Hormones Flashcards
what does endocrine refers to
a hormone that is produced and secreted within the body
what is the opposite of endocrine
exocrine
what is exocrine
something secreted outside of body
examples of exocrine
mammary glands
lumen of digestive tract
where does endocrine act
a distance from the release site
what a does paracrine act on
nearby cells
what does autocrine act on
its own secreting cell
what is neuroendocrine
synthesized by nervous tissue and carried in the blood
what is a gland
a cluster of cells organized for synthesis/release of compound
what are the 2 general types of glands
endocrine
exocrine
what are hormones
regulatory chemicals produced in an endocrine gland or scattered cells, secreted into the blood and carried to its target cell that responds by altering its metabolism
what are hormones involved in maintaining
homeostasis
what are hormones subjected to
tight regulation by feedback from target organs
what differs based on hormone structure
regulation of hormone synthesis and mode of action
what is feedback control
cyclic systems (loops) that control the amount of hormones released
what are steroid hormones
stepwise conversion of cholesterol by multiple enzymes
what is important about a steroid hormone’s structure
it is lipid soluble
what does a steroid hormone’s lipid solubility allow
leaving production cells and entering target organ by diffusion through the membrane
what are peptides, proteins and glycoproteins
chains of amino acids
for peptides, proteins and glycoproteins, what determines the primary structure and nature
the amino acid sequence
what hormones are generally amino acid derivatives
thyroid hormones
catecholamines
what are amino acid derivative hormones generally derived from
tyrosine and tryptophan
what are fatty acid derivatives or eicosanoids usually
prostaglandins
what are fatty acid derivatives derived from
cell membrane phospholipids (arachidonic acid)
what are characteristics of fatty acid derivatives
produced locally
have mainly autocrine, paracrine effects
where is the pineal gland
on the roof of the 3rd ventricle, encapsulated by meninges
what does the pineal gland secrete
melatonin
what is the pineal gland under indirect influence of
the hypothalamic circadian center
what does the pineal gland play a major role in
sleep patterns and recognition of seasons
when is melatonin secretion stimulated in pineal gland
dark phases
how is the GI tract involved in hormones
the stomach wall secretes gastrin == local stimulation of acid secretion
hormones in the small intestine
secretin
cholecystokinin
gastric inhibitory peptide
what does secretin do
stimulates the pancreas
what does cholecystokinin do
stimulates pancreas and gall bladder
what does gastric inhibitory peptide do
inhibits stomach activity
what are 2 hormones from kidneys
renin
erythropoietin
what does renin do
increases aldosterone secretion by adrenal cortex
what does erythropoietin do
increases production of red blood cells in bone marrow
what is found in adipose tissue
adipocytes
what do adipocytes do
release leptins and other adipokines
where can leptin receptors be found
in hypothalamus
what does leptin do
gives info about energy storage status
regulates appetite
