Lecture 4 BIO270H1
October 3, 2012
o 4 types
Autocrine and paracrine signaling (short distance)
Diffusion occurs when the chemical messenger diffuses into a receptor.
Indirect signaling Endocrine signaling (long distance)
Neural signaling (long distance)
o Direct signaling
Hemichannel: 6 comexins
End notes: Electrical coupling and metabolic coupling to link tissues and cells.
Gap junctions are dynamic. They can be close and open.
Responsible of a group of cells against damaged cells.
o Indirect signaling
It has to produce and release its chemical messenger.
Messenger carried in extracellular fluid to target cell…….
Paracrine (soluble messenger)
Juxtacrine (membrane attached messengers)
Nervous system – diffuses across synapse.
Release of messenger to ext