Endocrine System (Final Exam) Flashcards
What are exocrine glands? Examples?
gland that secretes products through a duct opening || ex: sweat and saliva glands
What are endocrine glands?
ductless glands that secrete hormones into interstitial fluid then into bloodstream to reach distant target cells
What distinguishes exocrine from endocrine glands?
exocrine secretions end up outside of the body || endocrine secretions end up inside the body (ex: into bloodstream or another organ)
What are tropic hormones?
“hormone-controlling” hormone || stimulates the secretion of another hormone
What is the hypothalamus?
primary endocrine gland
What is the role/function of the hypothalamus?
responsible for integrating together the neural, endocrine, and behavioral functions especially those involved with regulating the internal environment
What is the short-loop feedback?
hormone secreted by anterior pituitary gland exerts negative-feedback to hypothalamus
What is the long-loop feedback?
hormone secreted by 3rd endocrine gland exerts negative-feedback to both/either anterior pituitary and/or hypothalamus
What is the median eminence?
junction of hypothalamus and infundibulum
What is the infundibulum?
connects pituitary gland and hypothalamus
***What influences the release of tropic hormones?
-
What is a permissive effect?
hormone-hormone interaction || hormone A needs to be present (even at low concentrations) in order for hormone B to exert its full effect
What releases the tropic hormone?
Hypothalamus
What are trophic hormones?
hormones that have a growth effect on the tissues its stimulating || regulates endocrine organ size
What is hyposecretion?
secretion of too little hormones
What is hypersecretion?
secretion of too much hormones
What do hyporesponsiveness and hyperresponsiveness refer to?
when the target cells don’t respond properly to a hormone
What is the adrenal gland?
a pair of endocrine glands (consisting of outer adrenal cortex and inner adrenal medulla) above each kidney
What are the 4 layers of the adrenal gland?
zona glomerulosa, zona fasciculata, zona reticularis, adrenal medulla
What hormone does the zona glomerulosa layer of the adrenal gland produce?
mineralocorticoid (ie: aldosterone)
What hormone does the zona fasciculata layer of the adrenal gland produce?
glucocorticoids (ie: cortisol)
What hormone does the zona reticularis layer of the adrenal gland produce?
androgens (ie: DHEA and androstenedione)
What hormone does the medulla layer of the adrenal gland produce?
epinephrine
What is epinephrine?
hormone that regulates organic metabolism (aka adrenaline)
**How is epinephrine released?
the autonomic nervous system sends signals (action potential) to the sympathetic preganglionic fibers
What are the hormones that respond to stress (“fight-or-flight”)?
epinephrine and norepinephrine
What is the adrenal medulla?
modified sympathetic ganglion whose cell bodies do not have axons
What is the cortical segment of the adrenal gland?
outer part of the adrenal gland - secretes steroid hormones
What is the medulla segment of the adrenal gland?
inner part of the adrenal gland - secretes amine hormones
What is the differences between the cortical and medulla segments of the adrenal gland?
cortical = steroid hormones || medulla = amine hormones
What is the pituitary gland?
endocrine gland that lies in bony pocket below hypothalamus; consists of anterior/posterior lobes
What is the anterior pituitary?
the anterior lobe of the pituitary consists of glands and endocrine cells, no neural cells are present unlike posterior
What is the posterior pituitary?
the posterior lobe of the pituitary gland that is an extension of the neural components of the hypothalamus
What hormones does the anterior pituitary produce?
growth hormone (GH), adrenocorticotropic hormone (ACTH), Prolactin, luteinizing hormone (LH), follicle stimulating hormone (FSH), and thyroid-stimulating hormone (TSH) [GAP-LiFT]
What hormones does the posterior pituitary produce?
oxytocin and vasopressin
What is the thyroid gland?
large ductless gland in the neck that secretes hormones regulating growth and development through the rate of metabolism
What is the role of iodine in the thyroid gland?
to create thyroid hormones T3 and T4 which are combinations of iodine and amino acid Tyrosine
What causes goiters?
when thyroid gland is exposed to too much TSH
What are thyroid follicles?
composed of a surrounding layer of specialized follicular cells that encloses a colloid
What is a colloid?
protein rich core of a thyroid follicle
What is iodide trapping?
circulating iodide is actively cotransported with sodium ions across the basolateral membranes of the epithelial cells
What are thyroid hormones?
control the basal metabolic rate and are necessary for growth and development - T4 and T3
What is calcitonin?
regulates blood calcium levels
What is a goiter?
an enlarged thyroid gland
What is hypothyroidism?
condition characterized by decreased plasma concentrations of T3/T4
What is hyperthyroidism?
increased plasma concentrations of T3/T4
What does absorptive state mean?
after eating, have a lot of glucose and amino acids etc that need to be absorbed = causes an increase in insulin
What does postabsorptive state mean?
after what you ate has been absorbed = release of glucagon
How does the absorptive/post-absorptive state compare to neurons?
increase of stimulus = increase in APs (increase in hormone = increase of its action) || decrease of stimulus = decrease of APs (decrease in hormone = decrease its effect)
What is the primary molecule used for energy?
ATP/GTP
What is the result of an increase of plasma insulin?
increase in glucose uptake/utilization
What is the result of a decrease of plasma insulin?
decrease in glucose uptake/utilization
How many hypothalamic tropic hormones are there?
7
What is PRH? What kind of hormone is this? What hormone does it affect?
prolactin releasing hormone - tropic - prolactin
What is PIH? What kind of hormone is this? What hormone does it affect?
prolactin inhibiting hormone - tropic - prolactin and dopamine
What is TRH? What kind of hormone is this? What hormone does it affect?
thyrotropin releasing hormone - tropic - thyroid hormone
What is CRH? What kind of hormone is this? What hormone does it affect?
cortical releasing hormone - tropic - adrenocorticotropic hormone (ACTH)
What is GHRH? What kind of hormone is this? What hormone does it affect?
growth hormone releasing hormone - tropic - growth hormone
What is GHIH? What kind of hormone is this? What hormone does it affect?
growth hormone inhibiting hormone - tropic - growth hormone
What is GnRH? What kind of hormone is this? What hormone does it affect?
gonadotropin releasing hormone - tropic - luteinizing and follicle stimulating hormones
What tropic hormones regulate Growth Hormone? What kind of hormone is this?
GHIH (inhibiting) and GHRH (releasing) – anterior pituitary tropic hormone
What tropic hormones regulate Adrenocorticotropic Hormone (ACTH)? What kind of hormone is this?
cortical releasing hormone – anterior pituitary tropic hormone
What tropic hormones regulate Prolactin? What kind of hormone is this?
PRH (releasing) and PIH (inhibiting) – anterior pituitary hormone
What tropic hormones regulate Luteinizing Hormone? What kind of hormone is this?
GnRH (gonad releasing hormone) – anterior pituitary hormone
What tropic hormones regulate Follicle Stimulating Hormone? What kind of hormone is this?
GnRH (gonad releasing hormone) – anterior pituitary hormone
What tropic hormones regulate Thyroid Hormone? What kind of hormone is this?
TRH (thyrotropin releasing hormone) – anterior pituitary hormone
What is another name for the Growth Hormone Inhibiting Hormone?
Somatostatin (SST)
What is the parathyroid glands?
4 glands located on the thyroid glands
What is the parathyroid hormone?
protein hormone secreted by the parathyroid glands
What does the parathyroid hormone control?
bone, kidney, and GI tract
What controls parathyroid hormone production?
extracellular concentration of Ca2+
What is the effect on parathyroid hormone production when there is a decrease of calcium in the extracellular
stimulates parathyroid hormone secretion
What is the effect on parathyroid hormone production when there is an increase of calcium in the extracellular
inhibits parathyroid hormone secretion
What is the pancreas?
exocrine organ helps digestion by secreting fluids and enzymes into the digestive tract
What is glucagon?
hormone of the post-absorptive state – promotes breakdown of energy storage molecules (catabolic reactions)
What is insulin?
hormone of the absorptive state – promotes synthesis of energy storage molecules (anabolic reactions)
What are the differences between glucagon and insulin?
glucagon is part of post-absorptive state and catabolic reactions || insulin is part of absorptive state and anabolic reactions
Where is glucagon secreted?
alpha pancreatic cells
Where is insulin secreted?
beta pancreatic cells
When is glucagon secreted?
when there is a decrease in plasma glucose levels and increase in sympathetic activity
When is insulin secreted?
when there is an increase in plasma glucose levels and increase in parasympathetic activity
