blood glucose regulation

Question 1

what chemical stimuli tell the body to mobilise energy sources

Answer 1

release of ion - Ca2+ during exercise
release of NTs - ACh during exercise
changes in substrate during exercise (plasma glucose)

Question 2

what happens with muscle glycogen utilisation as exercise intensity increases

Answer 2

depletion increases as intensity increases
- not full depletion in very high intensity (>90% VO2max) because fatigue happens first

Question 3

how does plasma epinephrine concen change with exercise intensity

Answer 3

increases as intensity increases
higher epi concen = higher glycogen utilisation

Question 4

what is muscle glycogenolysis triggered by

Answer 4

multiple systems
- increase in plasma epi
- increased calcium during muscle contraction

Question 5

what is the glucagon response

Answer 5

breakdown storage of fat and glycogen

Question 6

what is the insulin response

Answer 6

increase storage of glycogen and fat

Question 7

what is the response of insulin and glucagon during exercise

Answer 7

insulin = decreases
- don’t want anabolic hormone during exercise (want energy release)
glucagon = increases

Question 8

how does the glucagon to insulin ratio control the mobilisation of glucose and FFA

Answer 8

ratio increases (more glycogen) = more fat and glycogen mobilisation

ratio decreases (less glycogen) = more fat and glycogen buildup

Question 9

what are the conseqeunces of increasing insulin (to DECREASE blood glucose)

Answer 9

mediates entry of glucose into most cells
- increases diffusion via GLUT4 in muscle

increases muscle protein synthesis and decreases muscle protein breakdown

increases FFA and triglyceride synthesis in adipose tissue and liver
- glucose from blood into muscle cell - some converted to glycogen, rest converted to fat and triglycerides

• increases glycogen synthesis and decreases glycogenolysis in the liver and muscle

Question 10

what happens to the glucagon insulin ratio during exercise or fasting

Answer 10

increased ratio (more glucagon than insulin)
- stimulates hydrolysis of glycogen and fat from liver
- increased gluconeogenesis (creation of glucose from fat and protein stores)
- increased availability of fuel in plasma

Question 11

what are the health benefits of decreased plasma insulin

Answer 11

• maintains glucose level (prevents decline)
• mobilisation of glucose, FFA, and adipocytes
• decreases chronic insulin resistance (insulin receptors have time to recover)

Question 12

what is the relationship between exercise duration and catabolic hormone concen

Answer 12

increased duration = increase in epi, norepi, and glucagon
cortisol increases at the start of exercise and then decreases

Question 13

what is the hormonal regulation of fat metabolism (increased lipolysis) during exercise

Answer 13

lipolysis increased by:
- increased epi (adipose tissue and muscle)
- increased norepi (adipose)
- increased cortisol
- increased GH
- DECREASED insulin (builds up fat)