Chapter 9: Endocrine System and Hormones Flashcards
What do hormones control
Reproduction, Growth and development, Mobilization of body defenses, Maintenance of much of homeostasis, Regulation of metabolism
hormones are produced by what
specialized cells
cells secrete hormones into what
extracellular fluids
blood transfers hormones to what
target sites
what do target site hormones do
regulate the activity of other cells
what are amino acid-based hormones
proteins, peptides, amines
what are steroids
made from cholesterol
what are prostaglandins
made from highly active lipids
what do hormones affect
certain tissues or organs (target cells or organs)
what must target cells have in hormone action
specific protein receptors
what influences the working of the cells
hormone binding
what are the effects caused by hormones
changes in plasma membrane permeability or electrical state, synthesis of proteins (enzymes), activation or inactivation of enzymes, stimulation of mitosis
what is the steroid hormone action
diffuse through the plasma membrane of target cells, enter the nucleus, bind to a specific protein within the nucleus, bind to specific sites on the cell’s DNA, activation of genes that result in synthesis of new proteins
what is the nonsteroid hormone action
hormone binds to a membrane receptor, doesn’t enter the cell, sets off a series of reactions that activates an enzyme, catalyzes a reaction that produces a second messenger molecule, oversees additional intracellular changes to promote a specific response
what are hormone levels in the blood maintained by
negative feedback
