Endocrine System Flashcards
organs of endocrine system that secrete hormones
glands
signaling molecules that are secreted into blood stream, travel to target tissues, bind to receptors, and induce a change in gene expression or cellular functioning
hormones
can be classified by chemical structure (peptides, steroids, and amino acid derivatives) or by their target tissues (direct and tropic)
hormones
hormones made of amino acids and are derived from larger precursor proteins that are cleaved during post-translational modification
peptide hormones
hormones that are polar and cannot pass through plasma membrane
peptide hormones
hormones that bind to extracellular receptors because they are charged and can’t pass through plasma membrane
peptide hormones
a peptide hormone is considered the _____; it binds to the receptor and triggers transmission of the second messenger
first messenger
connection between hormone at surface and effect brought about by second messengers within the cell; possibility of amplification at every step
signaling cascade
hormones that exert effects that usually have rapid onset but are short lived
peptide hormones
hormones that are water-soluble so they are able to travel freely in the bloodstream with no need of a special carrier
peptide hormones
hormones derived from cholesterol, produced primarily in the gonads and adrenal cortex
steroid hormones
hormones that are minimally polar and can pass through the plasma membrane
steroid hormones
hormones that bind to cytosolic or intracellular receptors and promote a conformational change in them; this complex binds to DNA alternating transcription of a gene
steroid hormones
hormones that exert effects that usually have slow onset but are long lived
steroid hormones
hormones that are lipid-soluble so they cannot dissolve in the bloodstream and must be carried by specific proteins
steroid hormones
hormones derived from one or two amino acids, usually with few additional modifications; share features with both peptide and steroid hormones
include: epinephrine, norepinephrine, triiodothyronine, thyroxine
amino acid-derivative hormones
hormones that have major effects on non-endocrine tissues
direct hormones
hormones that have major effects on other endocrine tissues
tropic hormones
the bridge between nervous and endocrine systems
hypothalamus
process in the hypothalamus:
the final hormone (or product) of a pathway inhibits hormones (or enzymes) earlier in the pathway, maintaining homeostasis
negative feedback
the hypothalamus stimulates the _____ through paracrine release of hormones into the hypophyseal portal system, which directly connects the two organs
anterior pituitary
tropic hormone secreted by the hypothalamus:
promotes release of FSH and LH
GnRH (gonadotropin-releasing hormone)
tropic hormone secreted by the hypothalamus:
promotes release of growth hormone (GH)
GHRH (growth hormone-releasing hormone)
tropic hormone secreted by the hypothalamus:
promotes release of thyroid-stimulating hormone (TSH)
TRH (thyroid-releasing hormone)
tropic hormone secreted by the hypothalamus:
promotes release of adrenocorticotropic hormone (ACTH)
CRH (corticotropin-releasing hormone) / CRF (corticotropin-releasing factor)
tropic hormone secreted by the hypothalamus:
inhibits release of prolactin
PIF/dopamine (prolactin-inhibiting factor)
the hypothalamus interacts with the _____ via axons of nerves projected by the hypothalamus; ADH and oxytocin are synthesized in the hypothalamus then travel down axons to the _____, where they are released into the bloodstream
posterior pituitary