Physiology: Endocrine Control of Metabolism: Nutting Flashcards
What happens to insulin after a meal?
Increases 3-6 fold
What does insulin do overall?
Promotes utilization and storage of glucose
Does glucagon have any peripheral effects?
No, it is mainly active at the liver.
The pancreatic vein goes directly to the portal system… anatomy!
What does glucagon do in the liver?
Promote breakdown of stored products and creating new glucose
What is the purpose of glucagon?
To keep glucose constant during fasting, mainly for our nerves
How long would our circulating glucose last without adding to it?
1 hour
How much time would the glucose in our livers supply us?
1/2 day
How much time would the glucose in our muscles supply us?
1 day
How many g glygoen stores of glucose is stored in liver and muscle?
100g liver
200g muscle
How much time would our fat stores last us?
30-40 days! Fat is the most efficient storage source.
What cells can only live on glucose?
Nerves
RBC
WBC
Renal tubules
What proportion of the glucose do nerves take of the cells who only use glucose?
3/4! 150g to 50g
What percent is muscle of body mass?
50%
What percent of energy does muscle use at rest?
30%
So effecting muscle metabolism has a big effect!
What does muscle prefer to burn?
FA
Ketones
rather than glucose and AAs
When is muscle glycogen utilized?
Heavy excercise
What organs have glycogen?
liver
kidney
muscle
What happens with muscle glycogen is depleted?
It doesnt work well.
What organ (other than pancreas) sees the highest concentration of insulin?
Liver
What organ is most responsive to insulin?
Liver
What are the objectives of the body during feeding?
- fill Glycogen stores
- dont spill much glucose in urine
- utilize carbs and fats for energy
- package excess for later (aa–>protein)
What are the main biochemical pathways SHUT DOWN during feeding?
Gluconeoenesis Glycogenolysis Lipolysis Ketogenesis Protein degradation
What is glucose’s effect in fat?
Esterify FA to store triglycerides
Stop making FA to ship
What are FA and ketones action in muscle during FASTING?
decrease Glucose utilization
Do FA and Ketones need insulin to get into tissues?
NO!
Why are FA stored in Fat? Why are they shipped?
Storage: esterified
Ship: not esterified
What are the objectives during fasting?
- Keep glucose constant for CNS
- Decrease glucose utilization elsewhere
- Keep some glycogen reserves
- Burn fat for FA and Ketones energy
- Utilize “sparable” proteins (AA (mainly alanine)) glycerol, and lactate, for gluconeogeneisis
Fat cells make FA and glycerol. What happens to they glycerol?
Gluconeogenesis in the liver
The liver makes glucose out of what in fasting?
Glycogen AA's (from muscle) Glycerol (from fat) ----- Lactate (from RBC) Pyruvate
What do Nerves, RBC, WBC make when they eat up the glucose?
Lactate
Pyruvate
What portion of FA is burned directly by cells that can use them? What portion burned as Ketones?
2/3 FA
1/3 Ketones