What is a Hormone?
It is a chemical secreted by a cell or group of cells into the blood for transport to a distant target, where it is effective a very low concentrations.
What are Pheromones?
They are chemicals singals secreted into the external envirnomet
What is Cellular Mechanism of Action?
Hormones bind to receptors to initiate responses.
How is Hormone activity limited?
By Terminating secretion removing hormone from the blood, or teminating activity at target cell.
What is a Hormone's Half Life?
The rate of hormone breakdown
What are the three types of hormones?
1. Peptide/Protein Hormones
2. Steroid Hormones
3. Amine Hormones
What are peptide/Protein Hormones?
They are composed of 3 or more animno acids
What are steroid?
They are synthesized in smooth ER and derived from cholesterol
What are Amine Hormones?
They Derive from either tryosine or thrptophan
Peptide hormones are made as inactive __________ and processed to ______ that binds to surface receptors, are transported dissolved int he plasma and have a short half life.
Preprohormones and Prohormones
Many Endocrine reflexes involve the nervou system, either through _______ or through neurons that influence hormone release.
The Pituitary Gland is composed of what?
What are the Two Neurohormones are released by the posterior pituitary?
Oxyotcin and Vasopressin
What doe Trophic Hormones control?
The secretion of other hormones
A Thyroid-Stimulating hormone is not what?
It is not an amino acid derivative
Anterior pituitary hormones are controlled by what?
By Releasing hormones and inhibiting hormones from the hypothalamus
The Hyphothalamic Trophic Hormones reach the pituitary throught what?
The Hypothalamic-hypophyseal portal system
What are the six Anterior Pituitary Hormones?
What is Synergism?
If the combination of two or more hormones yields a result that is greater than additive
What is Antagonistic?
If one hormone opposes the action of another
Diseases of hormone excess are usually due to what?
Symptoms of hormone deficiency occur when too little hormone is secreted which is called?
What many reult from problem with hormone receptors or signal transduction pathways?
Abnormal Tissue Responsiveness
Physiology Ch7: Intro. To Endocrine System