In certain tumors of antibody-producing B lymphocytes, the cyclin D1 gene is translocated & its transcription is

under the control of an antibody-gene enhancer, causing elevated cyclin D1 production.

TLS Online TPP Program

#Id: 5558

#Unit 7. System Physiology – Animal

The key to the action of vasopressin on the collecting ducts is aquaporin-2 & stored in vesicles in the cytoplasm of principal cells

TLS Online TPP Program

#Id: 5559

#Unit 7. System Physiology – Animal

The effect is mediated via the vasopressin V2 receptor, cyclic adenosine 5-monophosphate (cAMP) & protein kinase A

TLS Online TPP Program

#Id: 5560

#Unit 7. System Physiology – Animal

Medullary collecting duct is permeable to urea, and there are special urea transporters that facilitate urea diffusion across the luminal and basolateral membranes

TLS Online TPP Program

#Id: 5561

#Unit 7. System Physiology – Animal

TLS Online TPP Program

#Id: 5562

#Unit 7. System Physiology – Animal

The concentrating mechanism depends upon the maintenance of a gradient of increasing osmolality along the medullary pyramids

TLS Online TPP Program

#Id: 5563

#Unit 7. System Physiology – Animal

This gradient is produced by the operation of the loops of Henle as countercurrent multipliers and maintained by the operation of the vasa recta as countercurrent

exchangers