PART 1 Flashcards
Allow cells to communicate with each other to regulate body activities
Chemical Messenger
Stimulates the cell that originally secreted it
Autocrine
Local messengers secreted by one cell type and affect neighboring cell
Paracrine
Secreted by neurons to activate another neuron
Neurotransmitter
Secreted into bloodstream by certain glands and cell
Endocrine
Includes glands and specialized endocrine cells
Endocrine system
Chemical messenger that is secreted into the blood, travels to a distant tissue& binds to specific receptor
Hormone
Nonpolar; include steroid hormones, thyroid hormones and fatty acid
Lipid- Soluble Hormones
Polar; includes protein, peptide, and amino acid
Water Soluble Hormones
Directly by blood-borne; are sensitive to blood levels of particular substance
Humoral Stimuli
Stimulated by action potential
Neural Stimuli
Hormone is secreted to stimulate the secretion of other hormones
Hormonal Stimuli
Secreted with the release of humoral stimuli
Companion hormones
Prevents further hormone secretion
Negative feedback
Self promoting system whereby the stimulation of hormone secretion increases overtime
Positive feedback
Proteins where the hormones bind
Receptors
Location on cell where the hormone binds
Receptor site
Tendency for each type of hormone to bind to one type of receptor
Specificity
Often found in cell nucleus where the lipid soluble hormone bind
Nuclear receptor
Finger like projection that recognize & bind specific nucleotide sequence in DNA
Hormone-Response Elements
Forms from the combination of hormone and its receptor
Transcription factor
Increases the synthesis of certain proteins that produce the target cell’s response
mRNA
Proteins that extend across cell membrane; where water soluble hormone binds
Membrane bound receptor
They act on already existing enzymes
Second messenger system
