fasting and starvation Flashcards
(27 cards)
Fed-Fast state
Fed state (absorptive state) - 3-5 hpurs after a meal
Fasted state (post absorptive state) - 6-12 hours after meal
Prolonged fasting state - 12+ hours after meal
insulin and glucagon ratio change during a meal
insulin is prominent
anabolism is prominent
glycolysis is in operation and gluconeogenesis is inhibited
Insulin and glucagon ratio during fasted state and prolonged fasted state
glycolysis is inhibited and gluconeogenesis is in operation
Pancreatic beta cells in fed cells
- Beta cells detect high levels of glucose
- ATP/ADP in cell increases
- ATP sensitive channels close
- Cell depolarises
- Calcium enters cell
- insulin release
FED state in liver
- increased glucose transport into liver cells
- increased glycogen and glycolysis
- increased phosphate pathway to produce NADPH
- increased acetyl CoA fatty acid and triglycerides
- Fatty acid beta oxidation inhibited
FED state in muscle
Increased glucose transport into muscle cells
increased glycogen synthesis
increased amino acid uptake
increased protein synthesis
FED state adipose tissue
increased glucose transport into adipocytes
increased production of DHAP and glycerol 3 phosphate
Triglycerides hydrolysed to fatty acids outside cells and transported into cells
glycerol 3 phosphate and TG synthesis
OVERNIGHT FAST i9n liver
Insulin secretion decreases and glucagon secretion increases
Glucose synthesis
increased gluconeogenesis
decreased glycolysis
increased glycogen breakdown and glucose release
OVERNIGHT fast Muscle
Decreased glycoslysis
incrreased lactate
increased glycogen breakdown
increasd lipolysis and FA production leading to FA beta oxidation
OVERNIGHT FASt adipose tissue
decreased glycolysis
increased lypolysis
FA released from adipose tissue and transported to other tissues for Beta oxidaiton
Prolonged fast - liver
- Glycogen stores becoming depleted
- reduces glycogen breakdown
- Energy supplied through gluconeogenesis and lypolysis
- TCA cycle decreased and increased acetyl CoA synthesis
- Acetyl CoA used for ketone body production
Muscle - PROLONGED fast
- Decreased glycolysis
- Increased lactate and alanine production for gluconeogensis
- glycogen stores depleted
- increased lipolysis and fatty acid production leading to FA beta oxidation
- increased muscle proteolysis to provide substrate for gluconeogenesis
adipose tissue - PROLONGED fast
- increased lipolysis of triglycerides to release FA
- Released to blood stream
- decreased glycolysis
Blood glucose levels after CHO meal
120-140 mg/dl
Blood glucose levels 2 hours following meal
80-100 mg/dl
Blood glucose level fasting for 12 hours
80mg/dl
Starvation for 3 days blood glucose levels
70 mg/dl
Starvation 5-6 week Blood glucose levels
60-65 mg/dl
Hypoglycemia
- State of low blood levels
less than 4mmol/L - common in infancy and early childhood
- can occur during excersise as adrenaline and glucagon release leads to sweating, increased HR, feeling of hunger
Prolonged hypoglycemia
<2.5 mmol/L
Leads to lack of glucose for brain function leading to confused state
brain uses ketone bodies
can lead to come be fatal
hyperglycemia
State of high blood glucose level - 11.1 mmol/L
result of body not removing enough glucose from blood
causes - diabetes, drugs, acute medical conditions
diabetes
Fasting blood glucose levels of 4-7 mmol/L
AKA pre hyperglycemic state
increasing prevalance:
Types of diabetes
Type 1
Type 2
Gestational diabetes
Type 1
Insulin dependent
develops around age 12
autoimmune disease causes destruction of pancreatic beta cells which produces insulin
Cause is not clearly define
Inherited (10% chance)
Can develop ketoacidosis - build of ketones which lowers blood pH can be fatal
