Download pancreas, in beta-cells of islets of Langerhans general, non

hormone: insulin
gland:
pancreas, in beta-cells of islets of Langerhans
target:
general, non-target
function: to decrease blood glucose
feedback loop
increased
blood glucose
b -cells in
pancreas
insulin
released
decreased
blood glucose
glucose converted
to glycogen
†
overstimulation
problems:
understimulation
problems:
stress:
understimulation may cause diabetes
high blood sugar levels
receptor:
beta-cells of islets of Langerhans
message
sent:
increase insulin production
effector:
glucose is converted into glycogen, in liver and muscles
feedback:
decreased blood glucose
hormone: glucagon
gland:
pancreas, in the alpha-cells of the islets of Langerhans
target:
general, non-target
function: to increase blood glucose
feedback loop
decreased
blood glucose
a -cells in
pancreas
glucagon
released
increased
blood glucose
glycogen converted
to glucose
†
overstimulation
problems:
understimulation
problems:
stress:
understimulation may cause hypoglycemia
low blood sugar levels
receptor:
alpha-cells of islets of Langerhans
message
sent:
increase glucagon secretion
effector:
glycogen is converted to glucose in liver and muscles
feedback:
increased blood glucose
hormone: epinephrine
(or adrenalin)
gland:
adrenal medulla
target:
general, non-target
feedback loop
stress
hypothalamus
function: increases blood sugar (converts glycogen to glucose), heart
rate, breathing rate, cell metabolism; dilates blood vessels
and the irises of the eyes
adrenal medulla
body deals
with stress
overstimulation
problems:
increase in heart rate,
glucose, breathing,
metabolism. blood
vessels and pupils
dilate.
understimulation
problems:
stress:
epinephrine
released
short-term stress or threat
receptor:
hypothalamus
message
sent:
spinal cord cells stimulate adrenal medulla to secrete epinephrine
effector:
adrenal medulla releases epinephrine
feedback:
body responds to epinephrine, recovers from stress
hormone: cortisol
gland:
adrenal cortex
target:
general, non-target
feedback loop
stress
hypothalamus
function: increases the concentration of amino acids, which are
converted to glucose in the liver, or used for protein
synthesis to repair cells, converts fats to glucose
overstimulation
problems:
pituitary
gland
amino acids in blood increase,
body repairs cells, fats broken
down to help conserve glucose,
glucose absorption inhibited
understimulation
problems:
stress:
long-term stress
receptor:
hypothalamus
message
sent:
tells pituitary gland to release ACTH, which signals the adrenal
cortex to release cortisol
effector:
adrenal cortex releases cortisol into bloodstream
feedback:
body responds to cortisol, recovers from stress
cortisol released
ACTH
released
hormone: parathyroid
hormone (PTH)
gland:
parathyroid gland
target:
kidneys, intestine, bones
feedback loop
function: increases levels of calcium in blood and decrease phosphate
low blood
high blood
parathyroid gland
Ca 2+
Ca 2+
levels
†
†
blood calcium
levels rise
overstimulation
problems:
understimulation
problems:
stress:
PTH
inhibited
intestines
if too little calcium and phosphate are
absorbed from foods, rickets may develop
absorb more Ca 2+
release more Ca 2+
bones
kidneys
reabsorb more Ca 2+
†
decreased calcium levels or increased phosphate levels
†
†
receptor:
parathyroid gland
message
sent:
n/a
effector:
parathyroid releases PTH
feedback:
PTH stimulates intestines to absorb more calcium, kidneys to
reabsorb more calcium and bones to release calcium into the blood
hormone: calcitonin
gland:
thyroid gland
target:
bone cells
feedback loop
increased
blood calcium
blood calcium levels decrease
due to increase in calcitonin
thyroid gland
function: decreases calcium levels in blood by increasing calcium
uptake levels in bone cells
normal
overstimulation
problems:
understimulation
problems:
stress:
decreased
blood calcium
increased or decreased blood calcium levels
receptor:
hypothalamus and pituitary gland
message
sent:
pituitary gland increases or decreases TSH secretion
effector:
change in TSH levels tells the thyroid to increase or decrease
calcitonin secretion
feedback:
blood calcium levels decrease
hypothalamus
blood calcium levels increase
due to decrease in calcitonin
pituitary
gland
thyroid gland
hormone: thyroxin
gland:
thyroid gland
target:
general, non-target
feedback loop
metabolism
thyroxin levels decrease thyroid gland
too fast
function: regulates the metabolism of cells
normal
overstimulation
problems:
hyperthyroidism: bulging eyes, increased heart
rate, nervousness
understimulation
problems:
TSH still being produced may cause the
thyroid to become overstimulated & enlarged
stress:
hypothalamus
pituitary
gland
metabolism thyroxin levels increase thyroid gland
too slow
metabolic rate change (too high or low)
receptor:
hypothalamus and pituitary gland
message
sent:
pituitary gland increases or decreases TSH secretion
effector:
change in TSH levels tells the thyroid to increase or decrease
thyroxin secretion
feedback:
the change in the level of thyroxin will normalize the metabolic
rate of the organism as well as the blood sugar level