Chapter 6 Flashcards
Electrical signals
changes in the membrane potential of a cell
Chemical Signals
secreted by cells into ECF, responsible for most communication within the body, ligands
Protein Binding
specificity, affinity, competition, saturation
Gap Junctions
cytoplasmic bridges
Contact-dependent
signals require cell-to-cell contacts physically, cell adhesion molecules (CAMs)
Long-distance
chemicals and electrical signals, local - auto/paracrine
Hormones
secreted by endocrine glands or cells into the blood, only target cells with receptors for the hormone respond to the signal
Neurotransmitters
chemicals secreted by neurons that diffuse across a small gap to the target cell
Neurohormones
chemicals released by neurons into the blood for action at distant targets
Cytokines
peptides, synthesized and secreted by all nucleated cells in response to stimuli, interferons, interleukins, CSF, growth factors, chemokine, made on demand
Signal Pathway
Ligand binds receptor, activates signal molecule, synthesis of new proteins
Lipophilic
diffuse through the cell membrane, usually bind cytosolic receptors or nuclear receptors
Lipophobic
bind receptors on the cell membrane
Membrane Receptors
ligand gated, G protein, receptor-enzyme, integrin
Ligan Gated
binding opens or closes the channel
G protein coupled
ligand binding to a G receptor opens an ion channel or alters enzyme activity
Cascade
inactive complex to active complex until conversion of a substrate to its final product
Second Messengers
cAMP, cGMP, IP3, DAG, Ca+
NO
produced by endothelial cells, diffuses into smooth muscle, vasodilation
CO
targets smooth muscle and neural tissue
H2S
targets cardiovascular system to relax blood vessels
