Neuroendocrinology W2 Flashcards
What makes up the neuroendocrine system?
Nervous system
Endocrine system
What does the nervous system do in the neuroendocrine system?
Uses transmitters to relay messages from one nerve to another or from a nerve to a tissue
What does the endocrine system do in the neuroendocrine system?
Releases hormones into blood to circulate to tissues
What does the endocrine gland do?
Release hormones directly into the blood (ductless)
What are the 2 classes of hormones?
Amino acids derivates
Peptides/protein
What are amino acid derivate hormones?
Thyroid hormones
Catecholamines
What are peptides/protein hormones?
ACTN
ADH
What is the effect of hormone on a tissue determined by?
Plasma concentration
Number of active receptors
What is plasma concentration determined? (4)
1) Rate of secretion of hormone from endocrine gland
2) Rate of metabolism or excretion of hormone
3) Quantity of transport proteins
4) Changes in plasma volume
How does rate of secretion of hormone from endocrine gland effect plasma concentration?
Magnitude of stimulatory input
Stimulatory versus inhibitory input
What is greater, stimulatory or inhibitory input?
Stimulatory
What are 3 factors that the magnitude of a hormone-receptor effect depends on?
Concentration of the hormone
Number of target receptors on the cell
Affinity of the receptor for the hormone
What is downregulation of a hormone receptor?
Decrease in receptor number in response to high concentration of hormone
What is upregulation of a hormone receptor?
Increase in receptor number in response to low concentration of hormone
What are the mechanisms of hormone action?
Activation of genes to alter protein synthesis
Activating “second messengers”
Altering membrane transport