Endocrine System Flashcards
endocrine system
the set of glands throughout the body that produce and release hormones into the bloodstream to chemically control other organs and functions
endocrine gland
organ that synthesizes and releases hormones into the bloodstream
hypothalamus
the part of the brain located below the thalamus that receives neural signals and controls the release of hormones from the pituitary gland or releases hormones itself in response to the signals
this can be considered the control center of the endocrine system
ADH (antidiuretic hormone)
a hormone that helps maintain fluid levels by acting on the kidneys to control urine production and water reabsorption
produced by the hypothalamus, released by the posterior pituitary gland
oxytocin
hormone that contributes to social bonding, pair bonding, and childbirth
produced in the hypothalamus and released by the posterior pituitary gland
GnHR (gonadotropin releasing hormone)
hormone synthesized and released by the hypothalamus that acts on the anterior pituitary, triggering the release of follicle stimulating hormone and luteinizing hormone
adrenocorticotropic releasing hormone
hormone synthesized and released by the hypothalamus that stimulates the anterior pituitary gland to release adrenocorticotropic stimulating hormone
thyroid releasing hormone
hormone synthesized and released by the hypothalamus that stimulates the anterior pituitary gland to release adrenocorticotropic hormone
growth hormone releasing hormone
hormone synthesized and released by the hypothalamus that stimulates the anterior pituitary gland to release growth hormone stimulating hormone
prolactin inhibitory factor
hormone that is constantly being synthesized and released by the hypothalamus, except for when a woman is breastfeeding
prolactin release is normally inhibited by this hormone, and stimulated when this hormone stops being released
pituitary gland
pea-sized structure in the brain that releases many types of hormones when stimulated by the hypothalamus
these hormones control many other endocrine glands
anterior pituitary gland
portion of the pituitary gland that receives signals from the hypothalamus through the hypophyseal portal system
only portion that synthesizes its own hormone for release
hypophyseal portal system
collection of blood vessels that connect the hypothalamus to the pituitary in order to transport paracrine hormones, allowing the hypothalamus to direct the pituitary gland’s actions
tropic hormones
hormones that stimulate other endocrine glands
eg FSH, LH, ACTH, TSH
FSH (follicle stimulating hormone)
synthesized and released by the anterior pituitary gland
helps control puberty and regulate reproductive processes
LH (luteinizing hormone)
synthesized and released by the anterior pituitary gland
helps regulate the menstrual cycle in women and triggers the production of testosterone
ACTH (adrenocorticotropic hormone)
synthesized and released by the anterior pituitary gland
stimulates the thyroid gland
direct hormones
hormones that stimulate a part of the body that is not an endocrine gland
growth hormone and prolactin
growth hormone
hormone synthesized and released by the anterior pituitary gland that stimulates growth in long bones and muscles via the release of other effectors, like IGF-I from the liver
prolactin
hormone produced and released by the anterior pituitary gland that stimulates milk production and lactation
posterior pituitary gland
portion fo the pituitary gland that stores and releases hormones (namely ADH and oxytocin) made in the hypothalamus
hormones produced and released by anterior pituitary gland
tropic: FSH (follicle stimulating hormone) LH (luteinizing hormone) ACTH (adrenocorticotropic hormone) TSH (thyroid stimulating hormone) direct: prolactin growth hormone FLAT PeG
hormones stored and released by posterior pituitary gland
ADH (antidiuretic hormone)
oxytocin
thyroid
endocrine gland located posterior to the thyroid gland that releases hormones responsible for maintaining calcium levels
parathyroid hormone
synthesized and released by the parathyroid gland when blood calcium levels are low
stimulates the reabsorption of calcium from bone tissue
adrenal gland
endocrine gland that is located on top of the kidney that releases epinephrine/adrenaline, norepinephrine, and steroid hormones
adrenal medulla
interior portion of the adrenal gland that is activated by the sympathetic nervous system and releases catecholamines (epinephrine and norepinephrine)
catecholamines
class of signaling molecules that includes epinephrine, norepinephrine, and dopamine
adrenal cortex
exterior portion of the adrenal gland that releases hormones as a part of the stress response, including aldosterone and cortisol
cortisol
glucocorticoid hormone synthesized and released by the adrenal cortex that helps control glucose metabolism and regulate the immune system as a part of the stress response
aldosterone
steroid hormone synthesized and released by the adrenal cortex that helps control blood pressure by affecting the retention of sodium and water
cortisone
steroid hormone synthesized and released by the adrenal cortex that has an anti-inflammatory effect
gonads
glands that release sex hormones (testosterone and estrogen)
ovaries in males and testes in females
estrogen
main female sex hormone
responsible for the development of secondary sex characteristics (eg breast development, female distribution of fat, wide hips, etc) and for regulating the reproductive system
testosterone
male sex hormone that is responsible for the development of secondary sex characteristics (eg facial hair, increased muscle mass, etc.)
pancreas
an endocrine gland that controls blood glucose levels through the production of insulin and glucagon
insulin
a hormone produced by the pancreas that is released when blood glucose levels are high to promote glucose absorption and storage
glucagon
hormone produced by the pancreas that is released when blood glucose levels are low to promote glycogen breakdown to release glucose into the blood
autocrine hormones
class of chemical messenger that acts on the same cell that produced it, or on the cells immediately around it eg interleukin
interleukin
a type of autocrine hormone that is both produced by, and acts on, T-cells
paracrine hormones
class of chemical messenger that acts on a regional level, affecting the cells around where it was produced
endocrine horones
a class of chemical messenger that is released into the bloodstream to reach its distant target
metabolism of hormones
the way in which the body controls hormone levels
hormones are constantly being broken down by the liver and filtered by the kidney to keep levels in check
negative feedback loops
a self-regulating process in which one of the outputs serves to reduce the stimuli that triggered the process or another upstream event
helps maintain equilibrium or homeostasis
protein and polypeptide hormones
chains of amino acids that serve as the majority of chemical signals in the body
made in the rough ER and act on receptors on the cell membranes of their target cells
polypeptide vs protein
polypeptide is a small chain of <100 amino acids
protein is a large chain of >100 amino acids
peptide bonds
carbon-nitrogen single bonds that connect amino acids
steroid hormones
cholesterol derived chemical signals
have a characteristic hydrophobic 4 ring structure and can easily pass through cell membranes to affect transcription and translation inside of the cell
tyrosine derivative hormones
chemical signals that are modified versions of the amino acid tyrosine
eg thyroid hormones and catecholamines
secondary messenger signaling
signaling mechanism by which hormones can create an effect in the receiving cell that involves the hormone binding to a receptor on the cell membrane
this binding causes the activation of molecules within the cell that create the desired effect, and has an amplification ability referred to as the “cascade effect”
G-protein coupled receptor
a type of transmembrane receptor that activates an internal cascade response when its ligand is bound
G-protein
a type of protein involved in cell signaling that is bound to a molecule of GDP
this receptor exchanges its GDP for GTP when activated, and is deactivated by hydrolyzing its GTP into GDP and a phosphate group
adenylate cyclase
protein that catalyzes the formation of cyclic adenosine monophosphate (cAMP) from adenosine triphosphate (ATP)
cyclic adenosine monophosphate (cAMP)
common secondary messenger produced by adenylate cyclase that activates a variety of proteins
signal amplification
the idea that one hormone molecule can cause the production of a lot of secondary messengers, leading to a large intracellular effect
primary messenger signaling
signaling mechanism by which a hormone causes its desired effect by diffusing through the membrane to bind to a receptor in the cytosol or nucleus
terpenes
class of molecules composed of repeating units of isoprene
isoprene
molecule with 5 carbons, four in a chain, and one that is branched off of carbon-2
can come together to form larger terpene molecules
monoterpene
molecule composed of two isoprene units
sequiterpene
molecule composed of three isoprene units
diterpene
molecule composed of two monoterpenes, or four isoprene units
sesterterpene
molecule composed of five isoprene units
triterpenes
molecule composed of three monoterpenes, or six isoprene units
tetraterpene
molecule composed of four monoterpenes, or eight isoprene units
pyrophosphate
molecule (or portion of a molecule) composed of two phosphate groups bound together
weak base and good leaving group
dimethyl allyl pyrophosphate
allylic isoprene unit that is one of the starting materials for steroid and cholesterol synthesis
isopentyl pyrophosphate
allylic isoprene unit that is one of the starting materials for steroid and cholesterol synthesis
gerenyl pyrophosphate
ten carbon molecule made from the reaction between dimethyl allyl pyrophosphate and isopentyl pyrophosphate
intermediate in the production of steroid hormones
farnesyl pyrophosphate
a 15 carbon molecule that is an intermediate in steroid synthesis
squalene
a triterpene that is made from the reaction between two farnesyl pyrophosphate molecules
this is an intermediate in steroid synthesis
cholesterol
a molecule made from the cyclization of squalene in the liver
this is a component of cell membranes and is a precursor to steroid hormones
steroid backbone
a four ring carbon chain made of three cyclohexane groups and one cyclopentane group
sex hormones
steroid based chemical signals that affect sexual characteristics or development
estradiol (E2) and estrone (E1)
estrogen hormones that are produced by the ovaries and affect the development of female secondary sex characteristics
progesterone
sex hormone closely related to pregnancy and fetal development
androgens
class of steroid sex hormones that includes testosterone and androsterone
androsterone
an androgen hormone that affects the development of secondary sex characteristics in males, along with testosterone
