Endocrine Control of Metabolism

Question 1

How are the hormones of the adrenal medulla secreted?

Answer 1

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

Question 2

How do catecholamines allow for arousal, papillary dilation, sweating, bronchial dilation, etc.?

Answer 2

They elevate in plasma glucose, glycerol, and free fatty acids, and

promote tachycardia and elevated vascular resistance

Question 3

Do epi and nor have a promoting or inhibitory effect on insulin?

Answer 3

inhibitory via adenylyl cyclase activity decreasing Ca2+ levels (along with somatostatin). So epi or nor would be associated with hyperglycemia

Question 4

What molecules might you see active in a state of fasting?

Answer 4

glycogenolysis would be promoted mediated by epi, glucagon, TH, and GH would be stimulated by the fasting

Question 5

What molecules promote protein synthesis?

Answer 5

GH (and thyroid hormone synergistically), IGF-1, and testosterone,

Question 6

What molecules promote proteolysis?

Answer 6

glucagon, cortisol, and epi

Question 7

What molecules promote lipogenesis?

Answer 7

insulin

Question 8

What molecules promote lipolysis?

Answer 8

epi, testosterone, GH, leptin, and thyroid hormone

Question 9

What are the main glucose events occuring in early fasting stages (3-4hrs)?

Answer 9

increased hepatic glucose production via glycogenolysis of hepatic glycogen stores via glucagon

Question 10

What are the main glucose events later in fasting and overnight?

Answer 10

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

Question 11

How is energy utilized during exercise?

Answer 11

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

Question 12

How much insuln secretion does a person in starvation have/utilize?

Answer 12

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

Question 13

What is a healthy BMI?

Answer 13

18.5-24.9

Question 14

What BMI is considered overweight?

Answer 14

25.0-29.9

Question 15

What BMI is considered obese?

Answer 15

30-39.9 (40+= morbidly obese or GRADE 3 overweight)

Question 16

What processes mediate obesity?

Answer 16

There is:

increased hepatic glucocneogenesis,

hyper-insulemia, and exaggerated release of FFA from abdominal adipocytes leading to upper-body obesity

Question 17

How does the body respond to stress?

Answer 17

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