Glucagon secretion is increased by stimulation of the sympathetic nerves to the pancreas, & sympathetic effect is mediated via β-adrenergic receptors and cAMP

TLS Online TPP Program

#Id: 10109

#Unit 4. Cell Communication and Cell Signaling

Tight junctions prevent the diffusion of: 

Macromolecules

Small water-soluble molecules

Ions

Membrane proteins 

Glycolipids

TLS Online TPP Program

#Id: 10110

#Unit 4. Cell Communication and Cell Signaling

Ca2+-dependent cadherin- mediated adhesion also plays an important role in tight-junction formation, stability, and function

TLS Online TPP Program

#Id: 10111

#Unit 4. Cell Communication and Cell Signaling

Gap junctions permit the passage of molecules as large as 1.2 nm in diameter (molecules smaller than 1200 Da).

TLS Online TPP Program

#Id: 10112

#Unit 4. Cell Communication and Cell Signaling

Ions, low-MW precursors of cellular macromolecules, products of intermediary metabolism, & small intracellular signaling molecules can pass from cell to cell through gap junctions.

TLS Online TPP Program

#Id: 10113

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 1356

#Unit 4. Cell Communication and Cell Signaling

The cytokines form a family of small, secreted signaling molecules (about 160–200 amino acids) that control growth and differentiation of cells.