How are the hormones of the adrenal medulla secreted?
Input from preganglionic nerve fibers from the ventral horn of spinal segments T5-L1 synapse in the medulla and release pre-formed vesicles of hormones into the medullary capillary system for disperal
How do catecholamines allow for arousal, papillary dilation, sweating, bronchial dilation, etc.?
They elevate in plasma glucose, glycerol, and free fatty acids, and
promote tachycardia and elevated vascular resistance
Do epi and nor have a promoting or inhibitory effect on insulin?
inhibitory via adenylyl cyclase activity decreasing Ca2+ levels (along with somatostatin). So epi or nor would be associated with hyperglycemia
What molecules might you see active in a state of fasting?
glycogenolysis would be promoted mediated by epi, glucagon, TH, and GH would be stimulated by the fasting
What molecules promote protein synthesis?
GH (and thyroid hormone synergistically), IGF-1, and testosterone,
What molecules promote proteolysis?
glucagon, cortisol, and epi
What molecules promote lipogenesis?
What molecules promote lipolysis?
epi, testosterone, GH, leptin, and thyroid hormone
What are the main glucose events occuring in early fasting stages (3-4hrs)?
increased hepatic glucose production via glycogenolysis of hepatic glycogen stores via glucagon
What are the main glucose events later in fasting and overnight?
the body switches over more to lipolysis to mobilize TAGs to provide nonesterified fatty acids as energy substrates for muscle, heart, and liver more via glucagon mainly and some catecholamines, GH, and cortisol (a modulator, not a direct effector of lipolysis)
NOTE: So you can measure HDL and LDL after an overnight fasting (minimum of 12 hrs) but not before
How is energy utilized during exercise?
The initial response to exercise is via CNS receptors which promotes epi release and some cortisol via hypothalamus response to liberate substrates from body stores (protein, glycogen, and fat) to generate ATP
How much insuln secretion does a person in starvation have/utilize?
None. No glucose so why have have insulin?
Everything is mediated mostly by stress hormones like cortisol, epi, nor, and glucagon which together work to increase substrate availability
What is a healthy BMI?
What BMI is considered overweight?
What BMI is considered obese?
30-39.9 (40+= morbidly obese or GRADE 3 overweight)
What processes mediate obesity?
increased hepatic glucocneogenesis,
hyper-insulemia, and exaggerated release of FFA from abdominal adipocytes leading to upper-body obesity
How does the body respond to stress?
stress decreases hormones such as GH that promote growth, TSH and 5'-deiodinase that promote thyroid function, and GnRH (i.e. might not be able to make a baby!) and increases secretion of cortisol and catecholamines to promote glycogenolysis, lipolysis, and proteolysis