Anatomy of endocrine
scattered glands that produce and release hormones into the blood
Function of endocrine
control of the body, but effects are slow and prolonged (opposite of nervous system, whose effects are fast but short-lived)
Gland types:
Exocrine
Endocrine
Mixed glands
Exocrine Glands
produce non-hormonal secretions through ducts
Endocrine Glands
ductless glands that produce hormones secreted directly into body fluids
Mixed glands
perform both endocrine and exocrine functions
Hormones
chemical messengers secreted by cells in order to affect the metabolic functioning of other cells in the body.
Structural Types of Hormones:
Amino acid based
Steroid based
Eicosanoids
Amino acid based Hormones
most hormones are proteins which are water soluble and must bind to cell membrane receptors
Steroid based Hormones
some hormones are built from cholesterol and are therefore lipid soluble. Only those secreted by gonads and adrenal cortex. These must attach to carrier proteins for transport in the blood and must bind to intracellular receptors
Eicosanoids Hormone
lipid based hormones that act locally (do not travel through blood). Ex’s – leukotrienes and prostaglandins – help to mediate inflammation
Hormone effects on target cells
1.Changes in cell membrane permeability
2.Synthesis of proteins or enzymes (gene regulation)
3.Induces cellular secretion
4.Stimulates mitosis, cell division