Endocrine regulation of energy metabolism/stress Flashcards
three major tissues involved in interconversion of energy substrates
liver, muscle, adipose
only ____ provides energy
CHO/fat
only excess _____ stored, not _____
CHO/fat
protein not stored (amino acids are converted for energy/storage
two alternate states of metabolism and their main energy source
absorptive state - ingested nutrients
post-absorptive state - stored nutrients
the absorptive state:
- ____ is main source of energy
- _____ forms of nutrients are favored
- _____ nutrients are stored
- _____-sparing state
- ingested glucose
- storage forms
- excess
- PROTEIN***-sparing state
post-absorptive state:
- _____ are catabolized
- _____=main source of energy
- minor sources (____, ____)
- ____ is enhanced
- _____-sparing state
- storage forms of nutrients
- stored glucose/fat
- glycerol, ketone bodies (from fatty acids)
- gluconeogenesis
- GLUCOSE**-sparing state (meaning glycogen breakdown in order to increase blood glucose levels)
Major hormones of energy metabolism:
- ____ - hypoglycemic hormone of the ____ state
- ____ - hyperglycemic hormone of the ____ state; also assisted by ____, ____, and _____
- insulin absorptive
- glucagon post absorptive
- glucagon assisted by EPI, cortisol, and GH
Insulin: transition to absorptive state:
- ____ levels during a fast = ____ effect on post-absorptive state (to avoid _____ caused by glucagon)
- Food = ____ in insulin - converts to ______ state
- Insulin lowers blood levels of ___, ____, and ____ by stimulating peripheral tissues, liver, and adipose tissue
- low = braking effect (avoids hyperglycemia)
- sharp rise = absorptive state
- glucose, amino acids, and fatty acids
insulin regulated by multiple factors:
- ____ (major control)
- increased _____
- increased _____
- ____ intake
- _____ stimulation
- inhibited by ______
- increased blood glucose
- increased blood amino acids
- increased GI hormones (food intake)
- food intake
- parasympathetic stimulation (food intake)
- inhibited by sympathetic stimulation ( and EPI)
factors that increase blood glucose:
_____ OR ___
- glucose absorption from GI tract
- hepatic glucose production (glycogenolysis or gluconeogenesis)
factors that decrease blood glucose:
______ OR ______
- transport of glucose into cells (for energy production or energy storage (glycogen or triglycerides))
- urinary excretion of glucose (occurs abnormally only when blood glucose levels are super high)
Diabetes Mellitus:
- loss of ____ = severe metabolic derangement
- excess _____ - hyperglycemia = ______ = _____
- excess _____ = hyperlipidemia= _____ = _____ + _____
- excess protein degradation = ______ = excess ______ + negative _______
- insulin
- glucose = polyuria = dehydration
- lipids = ketogenesis = ketonuria + metabolic acidosis
- protein degradation = aminoacidemia = excess gluconeogenesis + negative protein balance
GLUCAGON: TRANSITION TO POST-ABSORPTIVE STATE
- fall in plasma glucose ( + rise in ______) = glucagon rise - converts to _____ state
- glucagon raised blood levels of ___ and ____
- stimulates ____/____/____ in liver; ___ in adipose tissue; ___ in liver
- (amino acids) = post-absorptive state
- glucose and fatty acids
- glycogenolysis/gluconeogenesis/lipolysis
- lipolysis
- ketogenesis
EPINEPHRINE: SECONDARY POST-ABSORPTIVE STATE
- direct actions on ____ (causing ____), ____(causing ___), and ____/____(causing ____)
- indirect effects by inhibition of ____/stimulation of _____
- EPI raises ____ and ____ during fasting
- EPI secreted in response to ______ (stress), so important in __________
-adipose (lipolysis), liver (gluconeogenesis), liver/muscle (glycogenolysis)
-insulin or stimulation of glucagon
-glucose/fatty acids
-acute hypoglycemia
EMERGENCY ENERGY NEEDS (may cause rebound hypoglycemia)
CORTISOL/GH: ADDITIONAL POST-ABSORPTIVE ACTIONS
- minor physiological effects – stimulate ____ and ___ to support glucagon/fasting state
- GH directly stimulates ___ and indirectly stimulates ______(antagonizes ____)
- GH secreted in _____ (stress/exercise)
- cortisol enhances ____ + ______ + _____ (and antagonizes _____) in fasting/stress
-lipolysis and gluconeogenesis
-lipolysis
gluconeogenesis (antagonizes insulin)
-hypoglycemia
-lipolysis, gluconeogenesis, and protein catabolism (and antagonizes insulin)
Major hormonal responses to stress:
- ____
- ____
- ____
- ____
- ____
-increase EPI
-increase CRH/ACTH/Cortisol
-increase glucagon
-decrease insulin
-increase Renin/Agiotensin-aldosterone AND Vasopressin (ANG II system to conserve salt/water to expand plasma volume; help sustain BP)
(AngII and vasopressin cause arteriolar vasoconstriction)
insulin effects ____, ____, ____, _____
glucagon and EPI effect ____ and ____
- blood glucose, blood fatty acids, blood amino acids, muscle protein
- blood glucose, blood fatty acids (no effect on amino acids and muscle protein)
major stimuli for glucagon secretion: ___ and ____
low blood glucose OR high blood amino acids
major stimuli for insulin release: ___ and ____
high blood glucose OR high blood amino acids
major stimulus for EPI release:
sympathetic stimulation during stress and exercise
_____ is primary regulator of absorptive and post absorptive cycles
insulin
major stimulus for cortisol release:
stress
major stimulus for GH release: ___, ____, ____, ___
deep sleep, stress, exercise, hypoglycemia
cortisol is only hormone that stimulates ___ and ____ at the same time
glycogenesis in liver
gluconeogenesis in the liver
overall actions of cortisol in stress response: 3 things
- breaks down fat
- breaks down protein
- expands carbohydrate stores(glycogenesis) AND increases availability of blood glucose (gluconeogenesis)
why does exercise have a profound effect in diabetes mellitus patients?
because exercise or muscle contraction triggers insertion of GLUT-4 into the plasma membranes of exercising muscle cells in the absence of insulin.
major target tissues of insulin
liver, adipose tissue, and skeletal muscle
major target tissues of glucagon.
mainly the liver
how does insulin deficiency impact fat, protein and carbohydrate metabolism?
- Fat metabolism- increases lipolysis, increases fatty acids in blood, increases release of ketone bodies
- Protein metabolism- increased protein catabolism and muscle wasting, increased amino acids in blood, amino acids are used in gluconeogenesis to increase blood glucose
- Carbohydrate metabolism- glycogenolysis and gluconeogenesis proceed unchecked, hyperglycemia occurs with decreased glucose uptake in peripheral tissues.
