148 terms

DAT Bootcamp - Endocrine System

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the _____ system is a communicator system that monitors slower acting responses
endocrine
_____ secretions involve cells secreting hormones into the bloodstream
endocrine
_____ secretions involve cells secreting hormones into ducts
exocrine
_____ secretions involve cells secreting hormones to neighboring cells
paracrine
_____ secretions involve cells secreting hormones to themselves
autocrine
a _____ amount of hormones can have a _____ effect
small; large
hormones bind to very specific _____
receptors
a single type of hormone can elicit _____ in the body
multiple/different effects
hormones are _____ acting than electrical signals
slower
what are the 3 different types of hormones?
peptide; steroid; amino-acid derived
_____ hormones are made of short amino-acid chains
peptide
peptide hormones include:
all hormones from the hypothalamus & anterior pituitary; glucagon & insulin; calcitonin & PTH
peptide hormones (are/are not) H2O soluble, so they (do/do not) need carriers for travel through the blood
are; do not
peptide hormones _____ stimulate receptor cells
indirectly

(bind to a receptor on the cell surface to trigger changes/secondary messengers in a cell)
secondary messengers are produced by _____ stimulation of receptor cells
indirect

(such as with peptides)
what are some common secondary messengers?
cAMP; IP3; DAG; Ca2+
ATP --> cAMP by _____
adenylyl cyclase
what are the 3 main receptors peptide hormones will bind to indirectly stimulate target cells?
G protein-coupled receptors; receptor tyrosine kinases; ligand-gated ion channels
G protein-coupled receptors (GPCRs) are a type of _____ (location) receptor that can trigger _____
cell surface; 2nd messengers
GPCRs consists of _____ transmembrane domains that pass back and forth through the cell membrane
7
G proteins (guanine nucleotide binding protein) are associated with _____, and they bind to GDP/GTP
GPCRs
G proteins activate/deactivate other things
activate
what are the G protein subunits?
alpha, beta and gamma subunits
_____ are enzymes that phosphorylate
kinases
insulin is a _____ hormone
peptide
insulin is a peptide hormone that acts through _____ and 2nd messengers
receptor tyrosine kinases (RTKs)
RTKs will _____ & _____ when their hormone binds to them
dimerize, cross-phosphorylate
peptide hormones can also bind to _____-gated ion channels
ligand
ligand-gated ion channels _____ once a ligand binds, allowing certain ions to pass through
change their shape
_____ hormones are 4-ring structures that belong in the same family as lipids
steroid
where are steroid hormones synthesized?
smooth ER
steroid hormones include:
all adrenal cortex and reproductive organ hormones
steroid hormones are _____ (solubility)
lipid-soluble (hydrophobic)
steroid hormones require a _____ to travel in the blood
carrier
steroid hormones can pass directly through the _____
cell membrane
steroid hormones _____ stimulate receptor cells
directly
do peptide hormones or steroid hormones have a slower action time?
steroid hormones
steroids trigger changes from a _____ level
transcriptional level
what is the main amino acid of amino acid derived hormones?
tyrosine
where are amino acid derived hormones synthesized
rough ER and cytosol
what are the main amino acid derived hormones?
all hormones made by the adrenal medulla; T3 and T4
epinephrine and norepinephrine are amino acid derived hormones that act similarly to _____ hormones
peptide

(indirect stimulation)
T3 and T4 are amino acid derived hormones that act similarly to _____ hormones
steroid

(direct stimulation)
the hypothalamus is involved with maintaining _____
homeostasis
what are the 2 lobes of the pituitary gland?
anterior and posterior
the _____ is an extension of neurons from the hypothalamus
posterior pituitary (neurohypophysis)
which 2 hypothalamic hormones does the posterior pituitary store and release
ADH; oxytocin

The posterior pituitary does not produce these hormones
antidiuretic hormone (_____) targets _____ of the kidney, to reabsorb water and increase blood volume/pressure
ADH/vasopressin; nephrons
ADH/vasopressin is made by the _____ and stored in the _____
hypothalamus; posterior pituitary
oxytocin targets the _____ and _____, providing positive feedback for labor contractions and milk letdown, respectively
uterus; mammary glands
oxytocin targets the uterus and mammary glands, providing _____ feedback for _____ and _____, respectively
positive; labor contractions; milk letdown
oxytocin is made by the _____ and is stored in the _____
hypothalamus; posterior pituitary gland
the anterior pituitary (adenohypophysis) is made of _____ tissue, so it _____ hormones
glandular; produces its own
the _____ connects the anterior pituitary and the hypothalamus
hypophyseal portal system
a _____ is when a capillary bed is connected to another capillary bed through a portal vein
portal system
why are portal systems advantageous?
they allow for quick a diffusion of molecules from one tissue to another, without having to enter the systemic circulation
what are some of the key hypothalmic-releasing hormones, which act on the anterior pituitary (telling it to release the hormones it makes)
GnRH; TRH; CRH; GRH
what are the effects of GnRH (gonadotropin-releasing hormone) from the hypothalamus?
tells the anterior pituitary to release LH and FSH to the gonads
what are the effects of TRH (thyrotropin-releasing hormone) from the hypothalamus?
tells the anterior pituitary to release TSH to our thyroid glands

(also stimulates the anterior pituitary to release prolactin)
what are the effects of CRH (corticotropin-releasing hormone) from the hypothalamus?
tells the anterior pituitary to release ACTH
what are the effects of GHRH (growth hormone-releasing hormone) from the hypothalamus?
tells the anterior pituitary to release GH
what are the 2 classes of hormones released by the anterior pituitary?
tropic and direct
_____ hormones target and act on other endocrine glands
tropic
_____ hormones stimulate/act on organs
direct
follicle stimulating hormone (FSH) is a _____ hormone from the _____
tropic; anterior pituitary
follicle stimulating hormone (FSH) stimulates _____ and _____
follicle growth (ovary); sperm maturation (testis)
luteinizing hormone (LH) is a _____ hormone from the _____
tropic; anterior pituitary
luteinizing hormone (LH) triggers _____ and the production of _____
ovulation; sex hormones
stress leads to the release of adrenocorticotropic hormone (ACTH), which is a _____ hormone from the _____
tropic; anterior pituitary
ACTH stimulates the adrenal _____ to release _____ to combat stress
cortex; glucocorticoids
thyroid stimulating hormone (TSH) is a _____ hormone from _____, which stimulates the thyroid to produce T3 & T4
tropic; anterior pituitary
what is the function of T3 & T4?
they have various metabolic effects and have also been shown to influence tissue development in children
T3 & T4 are regulated by _____ feedback
negative
prolactin is a _____ hormone from the _____
direct; anterior pituitary
what are the 2 phases of prolactin effects?
stimulates mammary gland development during pregnancy; increases milk production after birth
growth hormone (GH) is a _____ hormone from the _____, which stimulates cell growth, reproduction, division
direct; anterior pituitary
another name for GH is _____
somatotropin
the _____ is a small gland in the brain that secretes melatonin
pineal gland
_____ regulates the circadian rhythm
melatonin
the largest endocrine organ in the body is the _____, which is located in front of the trachea
thyroid gland
what 3 hormones are manufactured/secreted by the thyroid gland?
T3 & T4; calcitonin
T4 has one more _____ atom than T3
iodine
T3 is the _____ form of the hormone
active (4x more potent than T4)

(T4 loses an iodine atom to become active T3)
T4 is the main circulating form because it is _____ than T3
more stable
under-secretion of T3 and T4 leads to _____ & a _____ metabolic rate
hypothyroidism; reduced
what are some symptoms of hypothyroidism?
lethargy; weight gain; low heart and respiratory rate
over-secretion of T3 and T4 leads to _____ & a _____ metabolic rate
hyperthyroidism; increased
what are some symptoms of hyperthyroidism?
hyperactivity; anxiousness; weight loss
hypothyroidism or hyperthyroidism can cause _____, which is the physical enlargement of the thyroid gland
goiter
where is calcitonin secreted?
parafollicular cells of the thyroid
what are the main functions of calcitonin?
decrease blood calcium
calcitonin stimulates _____ and inhibits _____; it also decreases Ca2+ reabsorption in the kidneys and intestines
osteoblasts; osteoclasts
what hormone does the opposite of calcitonin?
parathyroid hormone (PTH)
where is PTH secreted?
parathyroid gland
what is the primary function of PTH/the parathyroid gland?
increase blood calcium level
PTH stimulates _____ and _____ Ca2+ reabsorption in the kidneys and intestines
osteoclasts; increases
the pancreas has _____ and _____ functions
exocrine; endocrine
the _____ tissue of the pancreas secretes digestive enzymes through the pancreatic duct
exocrine
where does the pancreatic duct connect to?
duodenum of the small intestine
the _____ are endocrine pancreatic tissue
islets of Langerhans
what are the 3 key islet of Langerhans hormones?
insulin, glucagon, and somatostatin

(somatostatin =/= somatotropin (GH))
what are the 3 key islet of Langerhans cell types?
alpha (α); beta (β); delta cells (δ)
alpha (α) cells of islets secrete _____
glucagon
when is glucagon secreted from the alpha (α) cells of the islets?
during a low blood glucose level (typically during fasting or between meals)
what is the function of glucagon secreted from the alpha (α) cells of the islets?
increase blood glucose levels
beta (β) cells of islets secrete _____
insulin
when is insulin secreted from the beta (β) cells of the islets?
when there is a high blood glucose level, typically after eating
what is the function of insulin secreted from the alpha (α) cells of the islets?
decrease blood glucose level
delta (δ) cells of islets secrete _____
somatostatin (growth hormone inhibiting hormone)
what is the function of somatostatin secreted from the delta (δ) cells of the islets?
inhibits secretion of somatotropin (GH), glucagon, and insulin
we have _____ adrenal glands
2 (1 on top of each kidney)
what are the 2 main regions of an adrenal gland?
outer cortex and the inner medulla
the adrenal cortex is stimulated by _____ from the _____ pituitary
ACTH; anterior
the adrenal cortex only secretes _____ hormones
steroid
what are some examples of the steroid classes secreted by the adrenal cortex?
corticosteroids; mineralocorticoids; androgenic steroids
what are some corticosteroids examples?
glucocorticoids (cortisol); mineralocorticoids (aldosterone)
androgenic steroids are _____ sex hormones
male
androgenic steroids are mostly produced in the _____ for men
testis
men and women produce a small amount of androgenic steroids in the _____, which is significant for women, but not so much for men
adrenal cortex
the adrenal _____ is controlled by the sympathetic nervous system (fight or slight)
medulla
the adrenal medulla secretes only _____
amino acid derived hormones (catecholamines)
what are the 2 main catecholamines?
epinephrine (adrenaline); norepinephrine (noradrenaline)
the main role of the adrenal glands is to cope with _____
stress
what type of stress is taken care of in the adrenal medulla?
short-term stresses
what type of stress is taken care of in the adrenal cortex?
long-term stresses
catecholamines are released from the adrenal _____ during the _____ response, which deals with _____ stresses
medulla; fight or flight; short-term
what are the key functions of the catecholamines?
breakdown glucose; increase HR; bind alpha or beta receptors
what happens when catecholamines bind alpha receptors?
vasoconstriction (move blood away from unimportant organs)
what happens when catecholamines bind beta receptors?
bronchodilation and vasodilation (move oxygen and nutrients to important organs)
what types of cells do catecholamines act on?
any cells with adrenergic receptors
glucocorticoids (such as cortisol) are released from the adrenal _____ to handle _____
cortex; long-term stresses
what are the primary functions of glucocorticoids?
break down storage molecules to generate immediate fuel

(1 of the several mechanisms to raise blood glucose)
what types of cells do glucocorticoids act on?
muscle, liver, and fat cells
how do glucocorticoids reduce inflammation?
they lower the immune response

(hence why we are prone to sickness when we are stressed)
_____ (such as aldosterone) are secreted by the secreted by adrenal cortex
mineralocorticoids
what is the key function of aldosterone (mineralocorticoid)?
increase blood volume and BP
how does aldosterone increase BP?
increases reabsorption of Na+ and excretion of K+; H2O follows Na+
the hormones produced by the testes are called what?
androgens
what are the set of hormones produced by the ovaries?
progesterone and estrogen
what does LH do for females?
LH surge triggers ovulation --> corpus luteum
the corpus luteum produces _____
female sex hormones (progesterone & estrogen)
what does FSH do for females?
it develops follicles during the early stages of the menstrual cycle, which secrete small amounts of the female sex hormones
_____ are premature eggs bundled in a fluid-filled sac
follicles
what does LH do for males?
act on Leydig cells of the testis --> testosterone production
what does FSH do for males?
sperm maturation
what are the 2 different types of feedback loops?
positive and negative feedback loop
a _____ feedback loop reinforces a stimulus to get richer
positive
a _____ feedback loop loop inhibits itself and prevents the overproduction of certain hormones
negative