Lecture 5- Communication Flashcards
what drug has had the most drug sales?
ozempic (GLP- 1 inhibitor)
$50 BILLION in sales
which drugs have had the least amount in drug sales?
tocilizumab
blood pressure (beta blockers)
what are the 3 mechanisms for local cell to cell signaling?
gap junction dependent communication
contact dependent signals
local signaling
what are gap junctions?
channels that connect adjacent cells
cells are connected by cytoplasmic bridges
the two adjacent cells in gap junctions express proteins, what are they called?
connexions
because gap junctions are channels, this makes them a water filled pore (hydrophilic), why is this good?
allows small molecules and ions to diffuse from one cell to the next
where are gap junctions common?
heart muscle
smooth muscle
some neurons
what is each connexion made up of?
6 connexin monomers
how far apart are the two adjacent cells with gap junctions?
2-4 nm space
what is contact dependent signaling?
a molecule (ligand) in the extracellular matrix of one cell binds to a receptor in the membrane of the adjacent cell
what are examples of contact dependent signaling?
immune system
what is local communication?
paracrine and autocrine signaling
what does paracrine signaling mean?
signaling to cells in the immediate vicinity
what does autocrine signaling mean?
signaling to itself
what are 3 examples of long distance communication?
endocrine system
neurotransmitters
neurohormones (neuroendocrine)
what does the endocrine system do?
secretes hormones
chemicals get secreted into the blood that affect cells in other parts of the organism
what is the difference between endocrine and exocrine?
endocrine: refers to substance secreted into blood
(ex. insulin)
exocrine: refers to substances secreted into a duct
(ex. digestive enzymes from pancreas into pancreatic duct)
what is the process of endocrine signaling?
endocrine cell releases ligand into the blood
ligand leaves blood stream and binds to a receptor on another cell
ligand comes into contact with most cells in the body, why might it not bind to them?
if the cell has no receptor
if the receptor isn’t specific to that ligand
how do neurotransmitters work?
an electrical signal travels distance along a nerve cell, axon releases a chemical, chemical travels across a small gap onto a target
explain where neurotransmitters release their ligands
ligands get released into the extracellular than attach to target cell
how do neurohormones (neuroendocrine) work?
an electrical signal travels distance along a nerve cell, causes a release of a chemical, the chemical is released into the blood and then leaves the blood to bind to its target cell
