Tight junctions seal off body cavities and restrict diffusion of membrane components

TLS Online TPP Program

#Id: 1226

#Unit 7. System Physiology – Animal

Vitamin D and PTH appear to stimulate production of mature osteoclasts through the dual action:

 1. Inhibiting OPG production

2. Stimulating RANKL formation

TLS Online TPP Program

#Id: 1227

#Unit 7. System Physiology – Animal

Glucocorticoids promote osteoclast activity and bone resorption by :

1. Increasing RANKL production 

2. Decreasing formation of OPG

TLS Online TPP Program

#Id: 1228

#Unit 7. System Physiology – Animal

Estrogen stimulates OPG production

TLS Online TPP Program

#Id: 1229

#Unit 7. System Physiology – Animal

PTH actions on the kidney:

1.  Inhibits phosphate reabsorption

2.  Stimulates Ca2+ reabsorption

TLS Online TPP Program

#Id: 1230

#Unit 7. System Physiology – Animal

PTH stimulates renal 1α-hydroxylase.

TLS Online TPP Program

#Id: 1231

#Unit 7. System Physiology – Animal

1α-hydroxylase, converts 25-hydroxycholecalciferol to the active form, 1,25-dihydroxycholecalciferol.