Endocrine and Metabolism Flashcards
How much glucose is circulating in your blood right now
About one hours worth, if I had no backup, i’d die after that
Most efficient energy storage form?
Fat
What tissues can only use glucose for energy production
nerves (brain), rbcs, wbcs, renal tubules
Remember this about muscle
- It is about 50% of body mass in a fit person and uses about 30% of the oxygen we consume.
- It is a GREAT thing that muscle loves to use Fatty Acids and Ketone bodies for energy because this spares glucose from oxidation
Most immediate source of glucose INSIDE the body is?
Hepatic Glycogen
What organ is most responsive to insulin, receives the most insulin? And what does insulin do?
The liver receives the most insulin, is most responsive to Insulin.
Insulin inhibits hepatic glucose output and thus increases glucose uptake/
Objectives during and right after a meal?
1) TO FILL glycogen stores
2) TO not spill any glucose into the urine
3) To utilize ingested carbs and fat for energy and to package the excess carbs and fats.
What is the best and most common way of packing carbs and fats for use at a later time?
TAGS (FUCKING REMEMBER THIS!!) M1s know this better than you and that is bad. TRI- ACYL- GLYCEROLS
KNOW THE GLUCOSE FATTY ACID CYCLE
ok
What are the objectives between meals?
1) Keep Glucose at a relatively constant level (above 70 for brain and never function)
2) Decrease glucose utilization in organs where it is not a neccesity
3) Keep some glycogen reserves
4) Burn fats for energy (FA, KB)
Utilize sparable proteins
In regards to hormones that act on metabolism, what are the short acting hormones
Insulin
Epinephrine and Norepinephrine
Glucagon
What is the primary mechanism (basic) of the short acting hormones?
Increase or Decrease the enzyme or protein ACTIVITY
Activity meaning the sensitivity of enzymes to hormonal or allosteric regulators
What are the long acting hormones on metabolism?
Growth Hormone
Thyroid hormone
Gluccocorticoids
Sex steroids
What is the mechanism of the long acting hormones?
Increase or decrease the enzyme of protein AMOUNT
Growth hormone’s effects on protein synthesis after a meal
increases it
T3’s affect on protein synthesis after a meal?
increases it.
What actions does Cortisol have between meals?
Permissive actions.
Allows gluconeogenesis and lipolysis
GH in between meals
lowers glucose utilization and increases lipolysis
T3 in between means
inc in lipolysis
KNOW the graph regarding the synergistic effects of cortisol, glucagon, and epinephrine
ok
What are the big lipolytic substances?
Epinephrine and Norepinephrine
Stimulate cAMP and activates Hormone sensitive lipase to convert TAG into Fatty Acids. THIS IS VERY BASIC>MUST KNOW
Major anti-lipolytic hormone
insulin…does the opposite to cAMP and hormone sensitive lipase.
What three hormones make Norepinephrine and Epinephrine more lipolytic?
Cortisol, growth hormone, T3
Glucocorticoids promote gluconeogenesis in many ways
In the liver:
- They have previously induced synthesis of key gluconeogenic and amino acid metabolizing enzymes
- They raise the hepatic responsiveness to glucagon
Peripherally they drive amino acid release from muscle and glycerol release in adipose which turns into glucose in the liver.
Know the figure on control of hypoglycemia
ok
SNS activity decreases while we’re eating a meal and increases again afterwards
ok
What happens to growth hormone as you fast for a number of days
continues to rise
Glucagon as you fast?
rises up to about 150 and holds steady
Cortsiol during fasting
stays pretty constant
T3 during fasting
falls….decreases T4 to T3 conversion since T3 increases BMR
KNOW THE BIG FEEDING AND FASTING CHART
ok
Between meals, what does COrtisol do?
Has PERMISSIVE ACTIONS
- allows for gluconeogenesis and lipolysis
- mild reduction in glucose uptake and utilization.
Remmeber, Cortisol wants glucose to be in the blood
GH between meals
similar to cortisol
