Habibi Part 3 Flashcards
[ ] is regulated by hormones to maintain energy homeostasis, adapt to physiological demands, and respond to stress.
metabolism
give 2 examples of pancreatic hormones
insulin and gulcagon
2 examples of adrenal hormones
glucocorticoids and adrenaline
what does insulin do
Decreases blood glucose levels by facilitating glucose uptake and storage.
what does glucagon do
Opposes insulin by** increasing blood glucose** levels through glycogen breakdown and gluconeogenesis.
what do glucocorticoids (like cortisol) do
Mobilize energy during stress by breaking down proteins and fats.
what does adrenaline do
Prepares the body for fight-or-flight responses by increasing glucose and fatty acid availability.
what does growth hormone (GH) do
Enhances lipolysis and opposes insulin’s glucose-lowering effects.
what does thyroid hormone (T3 or T4) do
Regulate basal metabolic rate and enhance protein, fat, and carbohydrate metabolism.
what does prolactin do
Regulates metabolism during pregnancy and lactation
what does estrogen do
Influence metabolic activity, especially during pregnancy, in ovulation stages
in a 90g intake of gluocose, where does most of it go
to muscles
in a 90g intake of glucose, where does it go least
fats
order these: glucose-6-p, ATP, pyruvate, acetyl coa, TCA intermediates, glycogen, glucose, ribose 5p, lactate, amino acids, glycolysis, glycogen synthesis
glycogen –> glycogen synthesis—> glucose-6-p —-> glycolysis—>pyruvate–> acetyl coa —> TCA intermed —> ATP
glucose<——- glucose 6-p ——>ribose 5-p
lactate<—- pyruvate—-> amino acids
the endocrine cells of the pancreas are contained in the pacreatic islets or [ ]
islets of langerhans
The Islets of Langerhans within the pancreas contain specialized endocrine cells: 3 types
alpha cells, beta cells, delta cells
alpha cells do what? what of beta cells? and delta cells?
alpha: secrete glucagon
beta: secrete insulin
delta: secrete somatostatin and gastrin.
out of beta, delta, and alpha cells, which is the most in the islets
beta
structure of insulin
insulin has [ ] amino acids in two chains [ ], connected by ____ (S-S) bonds.
51, A and B, disulfide
insulin structure
Insulin is produced as a larger molecule, ____, which is cleaved to form ____ insulin and ____ .
proinsulin, active insulin, C-peptide
what does insulin do
REDUCE BLOOD GLUCOSE LEVELS
____ is the main hypoglycemic hormone
insulin
the secretion of insulin is affected by: ____ blood glucose levels, ____ amino acid levels, ____ hormones (what type), and ____ by sympathetic activity from ____ (hormone, an alpha cell)
increased, elevated, gastrointestinal, inhibited, norepinephrine
increases glucose uptake
insulin promotes glucose uptake by promoting glucose entry into what kind of cells
muscle, heart, and fat cells via GLUT4 transporters.
what kind of cells does insulin NOT act on, in other words, where is glucose entry insulin independent
renal tubules, RBCs, liver, or brain
how does insulin enhance glycogen storage
Activates glycogen synthase, ot allow for storage
how does insulin promote lipogenesis
Increases fat synthesis by enhancing glucose transport into fat cells
insulin promotes amino acid ____ and ____ protein breakdown.
uptake, reduces
insulin ____ fat breakdown to conserve energy stores.
reduces
insulin ____ glucose oxidation in adipose or fat tissue
increase
what disease is this: Autoimmune destruction of beta cells, leading to insulin deficiency.
T1D
what disease is this: Reduced insulin sensitivity or secretion, often associated with obesity.
T2D
glucagon has ____ amino acids and is a ____ molecule that ____ insulin
29, hyperglycemic, anatagonizes
which cells, alpha, beta or delta, releases insulin
beta
how is glucagon stimulated to be released (2 ways)
low glucose levels and increased amino acid levels
what cell type releases glucagon
alpha cells
what does glucagon do in the liver
breaks down glycogen or converts AA and fats into glucose in the liver.
The adrenal gland has two regions:
adrenal medulla and cortex
what does the adrenal medulla do
secrete hormones like adrenaline, dopamine, and noradrenaline
3 roles of adrenaline
increases glucose
stimulates fat breakdown
inhibits insulin and promotes glucagon
the adrenal cortex is split into these 3 parts: Zona Glomerulosa, Zona Fasciculata, and Zona Reticularis. what do each do.
Glo: mineralocorticoids e.g., aldosterone
Fasci: glucocorticoids (e.g., cortisol)
Reticularis: gonadocorticoids (e.g., androgens
for glucorticoid secretion, like cortisol, what regulates it
HPA axis
for glucocorticoid secretion like cortisol, what does the hypothalmus, pituitary and adrenal cortex each release
H: CRH (cortico tropin releasing hormone)
P: ACTH (adrenocorticotropic hormone)
A: cortisol
how does cortisol affect the liver
more glucose, promotes glycogen synthesis
how does cortisol affect the muscle and fat
increases protein breakdown, fat breakdown, releases amino acids for free enrgy
what does cortisol do to the immune system
supress immune system
which hormone causes hyperglycemia and muscle wasting
high cortisol levels
Summary of Hormonal Effects on Metabolism
Insulin:
Lowers blood glucose by increasing uptake and storage.
Promotes an anabolic state (building molecules like glycogen and fat).
Glucagon:
Raises blood glucose by stimulating glycogen breakdown and gluconeogenesis.
Promotes a catabolic state (breaking down stores for energy).
Adrenaline:
Mobilizes energy in fight-or-flight situations.
Increases glucose and fatty acids in circulation.
Cortisol:
Long-term stress response hormone.
Promotes energy availability by breaking down proteins and fats.
