Endocrine: Definitions 11.1 and 11.2 Flashcards
Hormone:
Chemical messengers secreted by endocrine glands into the blood.
Target Cell:
The cell that has the specific receptors for a hormone.
Tropic hormone:
A hormone sent by a gland to another gland.
Secretion:
A chemical released by the cell, such as a hormone or digestive enzyme.
Exocrine gland:
A gland that secretes its chemicals into a duct (channel). Example: Sebaceous gland
Endocrine gland:
A gland that secretes its chemicals into the interstitium and then bloodstream.
Hypersecretion:
Above normal secretion.
Hyposecretion:
Below normal secretion.
Steroid hormones:
Lipid hormones made from cholesterol that can cross the lipid bilayer of the plasma membrane and go into the cell.
Protein (peptide) hormones:
Hormones made of amino acids, they cannot travel through the plasma membrane, so must bind to carbohydrate receptors on the outside of the cell.
Hormone receptor
Specific receptor that the hormone can attach to.
Synergistic hormone
Two or more hormones work together to produce a stronger response that either could do by itself. Example: testosterone and follicle stimulating hormone to produce sperm.
Antagonistic hormone
One hormone does the opposite action of another hormone. Example: glucagon and insulin
Negative feedback:
A hormone causes release of a substance that when that substance increases will inhibit the production of that same hormone. Most common feedback.
Positive feedback:
A hormone produces a response that continues to increase the hormone until something happens. Example – Oxytocin and contraction of uterine muscles during labor. Not a common feedback.