L22 - control during special circumstances Flashcards
Give three effects of insulin and three effects of glucagon
Insulin - GLUT 4 translocation for glucose uptake in muscle and adipose/glycolysis/glycogenesis/protein synthesis/lipogenesis
glucagon - Glycogenolysis/gluconeogenesis/lipolysis/proteolysis/ketogenesis
There are two main phases in pregnancy - the anabolic and catabolic phases. Briefly explain each
Anabolic - increase in maternal fat stores and a small increase in insulin sensitivity aids this. This is in preparation for the catabolic phase
Catabolic - Decreased insulin sensitivity favours this catabolic phase as the majority of the foetal growth occurs in the third trimester. The insulin resistance makes a lot of glucose and fatty acids available to the foetus
What metabolism occurs during feeding and what during fasting?
Feeding - increase in blood glucose stimulates insulin and all its effects we’ve gone over
Fasting - decrease in blood glucose. Glucagon has its effects. However ketogenesis and proteolysis only occur during starvation (after 10 hours)
What are the two important steroid hormones that control the fetoplacental unit in pregnancy?
Oestriol (an oestrogen) and progesterone
Briefly explain gestational diabetes
Increased appetite during pregnancy means more glucose is ingested -> Beta cell hypertrophy and hyperplasia occurs to produce more insulin to cope. If the beta cells can’t keep up with the insulin requirement then gestational diabetes ensues.
What is the major risk factor for gestational diabetes?
Obesity before pregnancy. Other risk factors include - older Mother/Non-caucasion/family history of gestational diabetes or foetal macrosomia
Note - many women who develop gestational diabetes will go on to have type 2 diabetes later in life
What are some potneital consequences to gestational diabetes?
Miscarriage/congenital malformation/foetal macrosomia (large baby)/shoulders get stuck during birth/preeclampsia in Mother
Metabolic rate needs to alter during exercise to ensure energy demands are met, brain is still sufficiently supplied with glucose and end products of metabolism are effectivley removed. Rate changes depending on type of exercise, intensity, duration and the condition of the individual. In which of the following exercises would the rate be the highest?
a) 100m sprint
b) 1500m race
c) marathon
a) - the sprint however the marathon will use more energy overall
Sometimes we need an immediate supply of ATP for a sudden energy demand. Glycolysis and Oxphos aren’t quick enough to supply this. Where does this ATP come from?
Creatine phosphate stores in the muscle
Exercise results in hepatic glucose production though glycogenolysis and gluconeogenesis, it also recylces lactate produced by anaerobic metabolism using what?
The cori cycle
There is also hormonal control of metabolism, this changes during prolonged exercise e.g. a marathon. Using this as an example: Insulin levels will fall over the course of the marathon due to inhibition by adrenaline. Glucagon will rise as will adrenaline, growth hormone and cortisol. What physiological benefits does exercise have on the body?
Body composition changes/glucose toerance improves/increased insulin sensitivity/blood triglycerides decrease/blood pressure drops/well being
