Glucose metabolism for the endocrine system.
common sense tells us that blood glucose levels must be maintained within
homeostatic levels for good health. we manage this somewhat through conscious
efforts such as maintaining balanced nutrient intake in regular exercise but
the bulk of work for this equilibrium is done unconsciously through negative
feedback systems within the body this learning activity examines some of those
hormones involved in glucose homeostasis. seven hormones help control glucose
metabolism. growth hormone: gh also called somatotropin, is an amino acid-based
hormone made by cells of the anterior pituitary gland. the main action of gh is
to stimulate cells to enlarge and divide because it is a growth hormone it is
anabolic in promoting protein synthesis gh increases the rate of fat usage by
cells and decreases the rate at which cells use carbohydrates for energy
Cyrax een thyroxine is made by the follicular cells of the thyroid gland
the follicular cells need iodides to produce thyroxine this hormone helps to
regulate the metabolism of lipids proteins and carbohydrates in cells
thyroxine enhances protein synthesis and lipid mobilization and stimulates the
cells use of carbohydrates as an energy source. cortisol: cortisol is a catabolic
steroid hormone made by cells of the middle layer of the adrenal cortex gland
it is a glucocorticoid that affects glucose metabolism cortisol works to
elevate the blood glucose level when it drops such as between meals or after
heavy exercise cortisol increases glucose levels by a process called
gluconeogenesis basically new glucose is made by the liver from non carbohydrate
sources namely amino acids and glycerol from triglycerides in order to have
amino acids and glycerol available for gluconeogenesis cortisol inhibits
protein synthesis and promotes the release of fatty acids from fat deposits
these fatty acid molecules are an energy source to preserve the already low
levels of available glucose abnormally high concentrations of cortisol are used
to reduce inflammation. Glucagon: this amino acid based hormone is made by the
alpha cells of the islets of langerhans which are endocrine portions of the
pancreas glucagon stimulates the liver to decompose stored glycogen into
glucose when blood glucose levels drop which can happen between meals or after
exertion this process called glycogenolysis helps to bring glucose
levels back toward normal glucagon also helps in the process of gluconeogenesis
after all glue kitchens main function is to elevate glucose levels. insulin: this
amino acid-based hormone is synthesized by the beta cells of the endocrine
portions of the pancreas the anabolic hormone is a hypoglycemic hormone in
that at lowers blood glucose levels when the glucose
is high, such as after a meal. it helps in facilitated diffusion processes in
getting glucose into cells for energy production. insulin stimulates the
process called glycogenesis which is the synthesis by liver cells of the
polysaccharide storage molecule glycogen from glucose. insulin also increases
protein synthesis and is antagonistic to gluconeogenesis. somatostatin: made by
delta cells of the pancreas this hormone controls the glucose metabolism by
inhibiting secretions of insulin and glucagon.
epinephrine norepinephrine: these fight-or-flight hormones tend to promote
processes to increase blood glucose levels. since fight-or-flight functions
demand the expenditure of more energy in conclusion many hormones and
processes help regulate glucose metabolism the various chemical and
neural controls and negative feedback loops help keep this most precious fuel
source in good balance and supply.
congratulations. you have completed this learning activity glucose metabolism for
the endocrine system.