Slow Block to polyspermy

When the cortical granules fuse with the egg cell membrane, they release protein-digesting enzymes that modify the zona pellucida proteins such that they can no longer bind sperm

TLS Online TPP Program

#Id: 5570

#Unit 7. System Physiology – Animal

The process keeps repeating & the final result is a gradient of osmolality from the top to the bottom of the loop

TLS Online TPP Program

#Id: 5571

#Unit 7. System Physiology – Animal

In juxtamedullary nephrons with longer loops and thin ascending limbs, the osmotic gradient is spread over a greater distance and the osmolality at the tip of the loop is greater.

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#Id: 5572

#Unit 7. System Physiology – Animal

Recirculation of Urea from the Collecting Duct to the Loop of Henle Contributes to Hyperosmotic Renal medullary interstitium and formation of concentrated urine

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#Id: 5573

#Unit 7. System Physiology – Animal

The recirculation of urea helps to trap urea in the renal medulla and contributes to the hyperosmolarity of the renal medulla.

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#Id: 5574

#Unit 7. System Physiology – Animal

There are four isoforms of the transport protein:  UT-A in the kidneys (UT-A1 to UT-A4) UT-B in the erythrocytes & descending limbs of the vasa recta 

TLS Online TPP Program

#Id: 5575

#Unit 7. System Physiology – Animal

Urea transporters UT-A1 and UT-A3 facilitate diffusion of urea out of the medullary collecting ducts while UT-A2 facilitates urea diffusion into the thin descending loop of Henle.