RPE65 is the enzyme in the pigment epithelial cells of the retina that catalyzes the isomerization of the intermediate esterified all-trans retinol to 11-cis-retinol.

TLS Online TPP Program

#Id: 4036

#Unit 7. System Physiology – Animal

When the cholinergic vagal fibers to nodal tissue are stimulated, the membrane becomes hyperpolarized and the slope of the prepotentials is decreased

TLS Online TPP Program

#Id: 4037

#Unit 7. System Physiology – Animal

Acetylcholine (ACh), released from parasympathetic nerve fibers, activates muscarinic (M2) receptors in the SA node.

TLS Online TPP Program

#Id: 4038

#Unit 7. System Physiology – Animal

activation of the M2 receptors decreases cyclic adenosine 3′,5′-monophosphate (cAMP) in the cells, and this slows the opening of Ca 2+ channels.

TLS Online TPP Program

#Id: 4039

#Unit 7. System Physiology – Animal

βγ subunit of a G protein, open a special set of K + channels. The resulting IKAch slows the depolarizing effect of Ih .

TLS Online TPP Program

#Id: 4040

#Unit 7. System Physiology – Animal

TLS Online TPP Program

#Id: 4041

#Unit 7. System Physiology – Animal