Endocrine System Flashcards
endocrine system includes which structures
pituitary, thyroid, parathyroid, adrenal, pineal glands
how does endocrine system communicate
chemical signaling: hormone is sent from endocrine organ into extracellular fluid than transported via bloodstream throughout body, then bind to receptors on target cells, takes longer than nervous system
autocrine
chemical that elicits response in same cell that secreted it; ex. Interleukin-1 which is important in inflammatory cells
paracrines
paracrine which is histamine, it typically doesnt affect neighboring cells but is released by immune cells in bronchial tree
what are the two major groups of hormones
amino acids: amines, peptides, proteins
lipids: steroids
endocrine systems includes all of the following except
salivary glands
what is meant by an autocrine chemical
one that causes a physiological change in the same cell that released it
the “stress hormone” cortisol has which of the following effects
increasing blood glucose levels
which anterior pituitary secretion stimulates gamete production
follicle-stimulating hormone (FSH)
the main difference in methods of maintaining homeostasis between the nervous & endocrine system is that
nervous system responds to changes in the external environment, whereas endocrine system does so internally
how do endocrine glands, such as the adrenal glands, differ from exocrine glands, such as sweat glands
endocrine glands are ductless, whereas exocrine glands deliver their product via specialized ducts
hormones derived from amino acids include all of the following except
steroids
permissive effect
presence of one hormone enables another hormone to act; ex. thyroid hormones have complex permissive relationships w/ certain reproductive hormones
synergistic effect
2 hormones w/similar effects produce an amplified response; ex. pituitary gland & estrogen from ovaries are required for fertilization
antagonistic effect
2 hormones have opposing effect; ex. pancreatic hormones insulin & glucagon work together to regulate blood sugar
humoral stimuli
changes in blood levels of non-hormone chemicals such as nutrients or ions
blood osmolarity refers to
concentration of solutes in the blood
when one hormone enables another hormone to act, this is termed the
permissive effect
which type of hormone diffuses easily through the cell membrane of the target cell
steroid
where is an intracellular hormone receptor located
inside their target cells
the function of ADH, anti-diuretic hormone, is to
signal the kidneys to reabsorb more water
where role does a feedback loop play in balancing hormones
negative feedback ensures that the body returns to homeostasis after hormonal imbalances
which of the following occurs after insulin is released from the pancreas
liver increases its storage of glucose in glycogen form
downregulation refers to
a decrease in the number of hormone receptors due to excessive hormone levels
two classes of hormones released by pituitary
releasing hormones & inhibiting hormones
what relationship do the hypothalamus & anterior pituitary exhibit
hypothalamus regulates secretions from the anterior pituitary
what is meant by the “hypophyseal portal system”
the capillaries w/in the infundibulum that connect the hypothalamus to the anterior pituitary
what is the relationship of retinal stimulation & sleep
light stimulating the retinas causes a decrease in melatonin production
what is the function of tropic hormones
to stimulate or depress the action of endocrine glands
which part of the pituitary gland is not responsible for synthesizing hormones
posterior
the hypothalamus is connected to the pituitary gland via the
infundibulum
what significance does the pineal gland have on circadian rhythms
pineal gland secretes melatonin to regulate sleep cycles
growth hormone (GH) aka somatotropin
protein hormone produced & secreted by anterior pituitary gland; primary function is anabolic promotion of protein synthesis & tissue building through direct & indirect mechanisms
thyroid stimulating hormone
aka thyrotropin; released from anterior pituitary in response to thyrotropin-releasing hormone from hypothalamus
two glycoprotein hormones in gonadotropins
follicle-stimulating hormone; stimulates the production & maturation of sex cells
luteinizing hormone; triggers ovulation & production of estrogens & progesterone by ovaries
adrenocorticotropic hormone
aka corticotropin, stimulates adrenal cortex to secrete cortisol
what is the relationship between alcohol consumption & ADH functionality
alcohol inhibits release of ADH, resulting in increased urine output
what is indicative of the endocrine disorder known as acromegaly
enlargement of hands & feets
as blood osmolarity decreases, what is the resulting action of osmoreceptors
prompt decrease of ADH secretion
what is the glucose-sparing effect of growth hormone
adipose cells are stimulated to break down stored fat in order to fuel growth
luteinizing & follicle stimulating hormone in males results in release of
testosteronewhat
what is another name for somatotropin
growth hormone
what is the function of melanocyte-stimulating hormone
it induces melanin production in the skin, which aids in protection from UV rays
what is the relationship between amount of urine produced & the secretion of antidiuretic hormone
urine output decreases as ADH levels increase
thyrotropin or TSH has what physiological effect
it triggers the thyroid to produce its hormones
what is the relationship between alcohol consumption & ADH functionality
alcohol inhibits the release of ADH, resulting in increased urine output
what is indicative of the endocrine disorder known as acromegaly
enlargement of hands & feet
what hormone is responsible for the production & stimulation of the gametes
follicle-stimulating hormone
timing of puberty starts w/ activity of which hormone
gonadotropin-releasing hormone
what is the role of adrenocorticotropic hormone in response to stress
stimulates adrenal cortex to release cortisol
thyroid gland responsible for
regulation of several processes, including basal metabolism, oxygen use, & AT
P production
parathyroid gland produces
parathyroid hormone; regulates blood calcium levels
thyroid produces 3 hormones
triiodothyronine, thyroxine, and calcitonin
how does the thyroid produce hormones
Hormones are produced in the colloid when atoms of the mineral iodine attach to a glycoprotein, called thyroglobulin, that is secreted into the colloid by the follicle cells
goiter
accumulation of colloid increases size of thyroid gland; when thyroglobulin accumulates in thyroid gland follicles
hypothyroidism symptoms
low metabolism, weight gain, cold extremities, constipation, reduced libido, menstrual irregularities, reduced mental activity
hyperthyroidism
pituitary/thyroid tumor; increased metabolic rate, excessive body heat, sweating, diarrhea, weight loss, tremors, increased heart rate; ex. graves disease
calcitonin
secreted by thyroid gland; produced by parafollicular cells; inhibits activity of osteoclasts, increasing osteoblasts, decrease calcium absorption in intestines, increasing calcium in urine
which gland is responsible for t-cell maturation & immune function
thymus
parathyroid gland
tiny, round structures usually embedded in posterior surface of the thyroid gland; usually 4; parathyroid glands are chief cells & involved in regulation of blood calcium levels
parathyroid gland produces peptide hormone PTH
in response to low blood calcium levels; PTH causes release of calcium from bones by stimulating osteoclasts
calcitriol
PTH initiates production of this steroid; stimulates increased absorption of dietary calcium by intestines
thymus
immune system organ & more active during infancy & early childhood & begins to atrophy as we age; produces thymosins
adrenal glands
wedges of glandular & neuroendocrine tissue adhering to top of kidneys; highest blood flow in the body; produces aldosterone, cortisol, cortisone, epinephrine, norepinephrine
adrenal cortex
component of hypothalamic-pituitary-adrenal axis; secretes steroid hormones important for regulation of long-term stress response, blood pressure & blood volume, nutrient uptake & storage, fluid & electrolyte balance, inflammation
adrenal medulla
releases hormones in response to acute short-term stress mediated by sympathetic nervous system; composed of postganglionic SNS neurons called chromaffin cells
zona glomerulosa hormones
mineralocorticoids; major is aldosterone regulates sodium & potassium in ions in urine, sweat & saliva
zona fasciculata
produce hormones called glucocorticoids because of their role in glucose metabolism
zona reticularis
produces small amount of steroid sex hormones called androgens
which of the following promotes the development of cushings disease
elevated cortisol secretion
what is the function of the chief cells in the parathyroid gland
they produce & secrete parathyroid hormone for blood calcium regulation
the renin-angiotensin-aldosterone system is responsible for the regulation of
blood pressure & fluid balance
the sympathetic response of epineophrine & norepinephrine secretion is controlled by signals originating in the
hypothalamus
which of the following is secreted by the adrenal medulla
epinephrine
what is the mode of action of the class of drugs known as ACE inhibitors
they block the enzymatic conversion of angiotensin I to angiotensin II
what body system does the thymus contribute to
immune
what function doe3s aldosterone serve
increases blood sodium levels
which of the following best describes the location of the parathyroid glands
they are embedded in the posterior surface of the thyroid
the pancreas secretes ____ in response to low blood sugar, and ___ in response to high blood sugar
insulin, glycogen
what do alpha cells of pancreatic islets produce
glucagon
type I diabetes is characterized by
bodys inability to produce insulin
what is the fate of unused glucose taken into the body
stored by liver & muscles as glucagon or as triglycerides in adipose tissue
which of the following do not require insulin for glucose uptake
erythrocytes
what is meant by the term glycolysis
breakdown of glucose for atp generation
what does peptide hormone gastrin effect
stimulates release of hydrochloric acid in stomach
what is function of pancreatic buffers
raise pH of stomach secretions before chyme moves to small intestine
vitamin D deficiency in adults is characterized by
softening of bones
when & which location is erythropoietin produced
kidneys when blood oxygen levels are low
what is the function of thrombopoetin
stimulate production of platelets
what is leptin & what is its functio
an adipose tissue protein that creates feeling of satiety after a meal
what organs are responsible for the creation of Vitamin D
skin, liver, kidneys
where in the body is erythrocytes produced
bone marrow
what happens to the thymus as we age
shrinks in size & replaced by connective tissue
