Absorptive and Post absorptive states

Question 1

What is absorptive state

Answer 1

where the food is being absorbed from the lumen of the GIT to the blood and lymph

Question 2

What is post-absorptive state

Answer 2

where the nutrients are not being absorbed so like during fasting

Question 3

what organ will the absorbed nutrients will go to first and what are the absorbed nutrients

Answer 3

• monosaccharides
  -AAs
  -Lipids
  will go to liver

Question 4

How can glucose be utilised in the tissues

Answer 4

• liver - becomes glycogen and TGs
• adipose tissue - make triglycerides (TG)
• muscles - glycogen
• other tissues - kerbs cycle to make energy

Question 5

How can AAs be utilised in the tissues

Answer 5

• liver - energy from keto acids

- muscle - protein

Question 6

How can TGs or lipids be utilised in the tissues

Answer 6

-adipose tissue where it can produce FAs and glycerol to make TGs

Question 7

How can the body switch from post absorptive to absorptive state when eating a meal

Answer 7

• when eating a meal, the blood glucose concentration and AAs increases.
• this triggers the beta cells of the islets of L to secrete insulin
• GLUT-2 takes in glucose to the beta cell
• this trigger the CA2+ influx for insulin exoxytosis
• insulin is now releases

Question 8

when do we go back to post absorptive from absorptie state

Answer 8

when the blood glucose conc and blood insulin conc falls

Question 9

What is GLUT-4 transporter

Answer 9

• glucose transporters where the glucose is taken in the cells like muscle and adipose.
• stimulated by insulin

Question 10

what processes occur in liver due to increase of glucose

Answer 10

• glycogen synthesis
  -glycolysis
  lipogenesis

Question 11

what processes occur in adipose due to increase of glucose

Answer 11

glycolysis

lipogenesis

Question 12

what processes occur in muscles due to increase of glucose

Answer 12

glycogen synthesis
glycolysis
lipogenesis

Question 13

what happens in POST-AB state

Answer 13

• maintains plasma glucose levels by regulating glucose supplying reactions (generating glucose) and glucose sparing reactions( generates other energy substrates)
• this is crucial because it preserves glucose for the brain

Question 14

what are the glucose supplying reactions

Answer 14

• glycogenolysis - breakdown of glycogen to glucose

- gluconeogenesis - producing glucose from AAs, lactate, glycerol

Question 15

what are the glucose sparing reactions

Answer 15

• TGs - fats through beta oxidation

- ketone bodies

Question 16

what happens in diabetes type 1

Answer 16

• since the glucose can’t be utilised due to insulin deficiency or resistance
• so the body will use up other energy fuels like TGs, AAs to make up for the energy needed
• leading weight loss

Question 17

what happens in the tissues if no glucose is taken into the cells

Answer 17

• increased glycogenolysis
  -increased lipolysis
• increases ectracellular glucose
  -breakdown of proteins into AAs for energy substrates
  -decreases glucose uptake
  decreased glycogen synthesis

Question 18

what are the clinical features of uncontrolled diabetes

Answer 18

• glucose level is high so the glucose absorption threshold is also high. leading to dehydration and polyuria
• impaired immune response - infections
• weight loss
  ketosis

Question 19

treatment for diabetes

Answer 19

• rehydration with IV saline

- insulin injections