Cell Communication Flashcards
Endocrine glands secrete – (chemical messengers) into blood
hormones
Hormones act on –, which must have appropriate – to bind the hormone and bring about a physiological response
target cells, receptors
The – is composed of endocrine glands located throughout the body and generally regulates activities that require – rather than sped
endocrine system, duration
comprise most hormones, including those secreted by hypothalamus, anterior and posterior pituitary, pancreas, and parathyroid
peptides
type of hormone derived from the amino acid tyrosine and include the hormones secreted by the thyroid gland and adrenal medulla
amines
adrenomedullary hormones are called
catecholamines
type of hormone that are neutral lipids derived from cholesterol; include hormones secreted by the adrenal cortex, ovaries and testes
steroids
– and – hormones are lipid soluble (lipophilic)
steroids and thyroid hormones
How are water soluble hormones transported?
dissolved in the plasma
How are lipophilic hormones transported?
bound to plasma proteins
How do hormones generally produce their effect?
by altering intracellular protein activity
Hormones bind with specific –
target cell receptors
Hormones bind to target cell receptors –> start chain of events in target cell –> which then
produce effects characteristic to that hormone
Based on the location of their receptors, hormones can be classified into – and –
plasma membrane receptors and intracellular receptors
hydrophilic peptides and catecholamines, being poorly soluble in lipid are unable to cross the lipid bilayer and bind to specific –
plasma membrane receptors
lipophilic steroids and thyroid hormones cross the lipid bilayer and bind to specific –
intracellular receptors (in cytoplasm)
T or F: Hormone responses can differ depending on the target cell
True
3 types of cell surface receptors
ligand-gated ion channels, G-protein linked receptors, enzyme linked receptors
Acetylcholine receptor is an example of –
ligand-gated ion channels
What do guanyl nucleotide binding proteins (G proteins) act as?
molecular switches
G proteins are active when – is bound
GTP
G proteins are inactive when – is bound due to action of intrinsic GTPase
GDP
insulin is an example of –
enzyme-linked receptors
What are the three types of extracellular signaling molecules?
hormones, paracrine signals, neurotransmitters
Cyclic AMP (cAMP) is formed from ATP by – an enzyme that is activated by a G protein
adenylyl cyclase
cAMP is a – messenger
second
most of the effects of cAMP involve binding to and activating
cAMP dependent protein kinase (PKA)
activated PKA phosphorylates specific proteins on – or – residues, leading to some physiological change
serine, threonine
Why so may steps in the Glycogenolytic cascade?
amplification
each molecule of epinephrine binding to its receptor on the liver plasma membrane can release – molecules of – into the bloodstream
10,000, glucose
– dephosphorylate key enzymes in glycogenolytic cascade
phosphatases
calcium binding protein
calmodulin
PIP2
phosphatidyl inositol 4,5 bisphosphate
DAG
diacylyglycerol
IP3
inositol trisphosphate
TNF can trigger
Tumor necrosis Factor can trigger apoptosis
signaling pathways such as the one involved in apoptosis can be very complex and interlinked
cross-talk
vessels get wider
vasodilation
Where is TSH found?
anterior pituitary
Where is FSH found?
anterior pituitary
Where is LH found?
anterior pituitary
Where is ACTH found?
anterior pituitary
Where is GH found?
anterior pituitary
Where is prolactin found?
anterior pituitary
Where is melanocyte found?
anterior pituitary
Where is endorphins and enkephalins found?
anterior pituitary
activates thyroid gland
Thyrotropin (TSH)
stimulates maturation of ovarian follicles in females; stimulates spermatogenesis in males
Follicle Stimulating hormone (FSH)
triggers ovulation and ovarian production of estrogens and progesterone in females; stimulates testosterone production in males
Luteinizing hormone (LH)
stimulates adrenal cortex to secrete cortisol
Corticotropin (ACTH)
stimulates protein synthesis and growth
Growth hormone (GH)
stimulates milk production
prolactin
melanin production
Melanocyte-stimulating hormone (MSH)
pain control
endorphins and enkephalins
anterior pituitary is controlled by the release and release-inhibiting neurohormones of –
the hypothalamus
posterior pituitary receives and releases –
2 hypothalamic hormones
stimulates contraction of uterus, flow of milk, inter individual bonding
oxytocin
promotes water conservation by kidneys
Antidiuretic hormone (ADH) or vasopressin
Where is thymosin found?
thymus (which diminishes in adults)
activates immune system T cells
thymosin
Where is insulin found?
Pancreas (islets of Langerhans)
Where is glucagon found?
Pancreas (islets of Langerhans)
Where is somatostatin found?
Pancreas (islets of Langerhans)
stimulates cells to take up and use glucose
insulin
stimulates liver to release glucose
glucagon
slows release of insulin and glucagon and digestive tract functions
somatostatin
Where is melatonin found?
pineal gland
regulates biological rhythms
melatonin
Where is thyroxine found?
thyroid gland
Where is calcitonin found?
thyroid gland
increase cell metabolism; essential for growth and neural development
thyroxine
stimulates incorporation of calcium into bone
calcitonin
Where is PTH found?
parathyroid gland
stimulates release of calcium from bone and absorption of calcium by kidney and gut
parathyroid hormone (PTH)
Where is cortisol found?
Adrenal Gland - cortex
Where is aldosterone found?
Adrenal Gland - cortex
Where is sex steroids found?
Adrenal Gland - cortex
Where is epinephrine found?
Adrenal Gland - medulla
mediates metabolic responses to stress
cortisol
involved in salt and water balance
aldosterone
stimulate immediate fight-or-flight response
epinephrine (adrenaline) and norepinephrine (noradrenaline)
development and maintenance of male sexual characteristics
testosterone
development and maintenance of female sexual characteristics
estrogen
supports pregnancy
progesterone
an intercellular chemical messenger that travels within body tissue
hormone
hormones can travel farther than – which are also chemical messengers
neurotransmitters
hormones travel between what two types of cells
endocrine cells and target cells
produces and/or stores hormones
endocrine cells
T or F: a target cell likely has more than one type of receptor and secondary messenger
TRUE
a chemical message that is released into surrounding extracellular fluids that exert only localized effects (paracrine, autocrine)
local hormones
a hormone that is released by mast cells; it diffuses into damaged tissue to dilate local blood vessels as part of the inflammation response
histamine
a chemical message released into the circulatory system with the goal of reaching more “distant” cells
circulating hormone
organs composed of clusters of secretory cells
glands
release secretions to outside of the body through ducts (e.g. salivary and sweat glands)
exocrine glands
“ductless” glands that store and release hormones into extracellular fluid from which it may enter the body’s circulatory system
endocrine glands
What two body systems mediate homeostasis?
nervous and endocrine systems
Hormones might be secreted by dispersed cells such as –, –, –
nerve cells (neurohormones), digestive tract cells, mast cells in tissue
TRF
thyrotropin-releasing factor
GnRF
gonadotropin-releasing factor
CRF
corticotropin-releasing factor
GRF
growth hormone -releasing factor
200 AA polypeptide. stimulates cells to take up AAs for protein synthesis. promotes body growth by stimulating live cells to produce somatomedins that stimulate bond and cartilage growth
growth hormone
helps in pregnancy and stimulates production and secretion of milk in females; helps control endocrine function of testes in males
prolactin
controls skin pigmentation; also believed to control unidentified functions
melanocyte-stimulating hormone
Adrenocorticotropin, MS< endorphins, and enkephalins are produced by cleavage – or large, parent polypeptide called –
proteolysis, propio-melanocortin
