Lecture 5- Communication

Question 1

what drug has had the most drug sales?

Answer 1

ozempic (GLP- 1 inhibitor)
$50 BILLION in sales

Question 2

which drugs have had the least amount in drug sales?

Answer 2

tocilizumab
blood pressure (beta blockers)

Question 3

what are the 3 mechanisms for local cell to cell signaling?

Answer 3

gap junction dependent communication
contact dependent signals
local signaling

Question 4

what are gap junctions?

Answer 4

channels that connect adjacent cells
cells are connected by cytoplasmic bridges

Question 5

the two adjacent cells in gap junctions express proteins, what are they called?

Answer 5

connexions

Question 6

because gap junctions are channels, this makes them a water filled pore (hydrophilic), why is this good?

Answer 6

allows small molecules and ions to diffuse from one cell to the next

Question 7

where are gap junctions common?

Answer 7

heart muscle
smooth muscle
some neurons

Question 8

what is each connexion made up of?

Answer 8

6 connexin monomers

Question 9

how far apart are the two adjacent cells with gap junctions?

Answer 9

2-4 nm space

Question 10

what is contact dependent signaling?

Answer 10

a molecule (ligand) in the extracellular matrix of one cell binds to a receptor in the membrane of the adjacent cell

Question 11

what are examples of contact dependent signaling?

Answer 11

immune system

Question 12

what is local communication?

Answer 12

paracrine and autocrine signaling

Question 13

what does paracrine signaling mean?

Answer 13

signaling to cells in the immediate vicinity

Question 14

what does autocrine signaling mean?

Answer 14

signaling to itself

Question 15

what are 3 examples of long distance communication?

Answer 15

endocrine system
neurotransmitters
neurohormones (neuroendocrine)

Question 16

what does the endocrine system do?

Answer 16

secretes hormones
chemicals get secreted into the blood that affect cells in other parts of the organism

Question 17

what is the difference between endocrine and exocrine?

Answer 17

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)

Question 18

what is the process of endocrine signaling?

Answer 18

endocrine cell releases ligand into the blood
ligand leaves blood stream and binds to a receptor on another cell

Question 19

ligand comes into contact with most cells in the body, why might it not bind to them?

Answer 19

if the cell has no receptor
if the receptor isn’t specific to that ligand

Question 20

how do neurotransmitters work?

Answer 20

an electrical signal travels distance along a nerve cell, axon releases a chemical, chemical travels across a small gap onto a target

Question 21

explain where neurotransmitters release their ligands

Answer 21

ligands get released into the extracellular than attach to target cell

Question 22

how do neurohormones (neuroendocrine) work?

Answer 22

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