hormonal responses to exercise - week 2 Flashcards
how is plasma glucose maintained ??(4)
mobilisation of glucose from liver stores
mobilisation of FFA from adipose tissue
glucogenesis from amino acids/lactic acids/glycerol
blocking entry of glucose into cells
give examples of hormones that are slow acting involved in blood glucose
thyroxine
cortisol
growth
give examples of fast acting hormones involved in blood glucose homeostasis
epinephrine
norepinephrine
insulin
glucagon
how does thyroid hormones effect us during exercise ?
slow acting
during stress increased levels
helps facilitate other hormones and reactions/ interactions
what is T3 role as a hormone ?
enhances effect of epinephrine to mobilise FFAs from adipose tissue
why is growth hormones essential for growth of all tissues?
increases amino acid uptake
protein synthesis
how does growth hormones relate to spare plasma glucose? (3)
reduces use of plasma glucose- preserves concentration
increases gluconeogenesis
mobilises fatty acids from adipose tissue
what can growth hormones be used for ? (3)
childhood dwarfism
athletes - hard to detect
elderly - wuecstioable benefits for anti-aging
what is cortisol?
slow acting steroid hormone derived from cholesterol
secreted from the adrenal cortex
what is cortisol stimulated by ? (2)
stress - adrenocorticotropic hormone
exercise
what is role of cortisol ? (3)
negative feedback loop
increases under stress
contributes to maintenance of plasma glucose
what happens to cortisol during exercise ??
directly proportional to exercise intensity
changes in cortisol is related to repair of exercise induced tissue damage
what is catecholamines ? (3)
known as adrenaline and noradrenaline
secreted from the adrenal medulla
part of the sympathetic nervous system
what is epinephrine ?
primary secretion/ secreter
what is noradrenaline ? (3)
a neurotransmitter
activates the NS and other hormones
part of fight or flight
what happens to catecholamines during exercise ? (2)
both concentrations increase in plasma
- symp NS activation
the more training someone has, the less its secreted/ greater capacity to control the levels
how does glycogenolysis relate to exercise ?
high intensity results in greater and rapid glycogen depletion
what is the role of plasma epinephrine in exercise ?? (2)
plasma epinephrine is simulator of glycogenolysis
greater increase of plasma epinephrine at high intensity at quicker speed
when plasma epinephrine is blocked, what still occurs ??
glycogen depletion still occurs
why does glycogen depletion still occur ??
breakdown is under dual control
important extracelluar and intracellular
what is the role of the pancreas? (3)
has both exocrine and endocrine functions
secretes insulin
secretes glucagon
what is role of insulin ?
promotes storage of glucose, amino acids and fats
what is the role of glucagon ?
promotes mobilisation of fatty acids and glucose
stimulates gluconeogenesis
what happens to plasma insulin during exercise ? (2)
moderate intensity exercise decreases insulin concentrations
favours mobilisation of glucose from liver and FFA from adipose tissue
what happens to plasma glucagon during exercise ?
person who is endurance trained will have little increase during exercise compared to someone untrained
how does exercise effect catecholamines on insulin/glucagon secretion ? (3)
when plasma glucose is constant the SNS can modify hormone secretion
trained person has decreased stimulation of the pancreas
able to maintain glucose levels more efficiently
during high intensity exercise what happens to FFA oxidation ?
FFA oxidation decreases
glucose is used more
can be due to insufficient blood flow to adipose tissue
how does training effect FFA mobilisation ?
training increases mitochondria so they can use more fat as a fuel and spare limited CHO
