Counter-Current Exchange

SOF

* Counter-current exchange (CCE) occurs when two bodies flow in opposite directions

* The exchange may involve heat or molecules

* The gradient that exists between the two flowing bodies determines total exchange

* The greater the gradient, the greater amount exchanged per unit time (or unit volume)

* The greater the surface area involved, the greater the exchange

* The pampiniform venous plexus (PVP) in the male mammal permits heat transfer

* The male PVP permits heat transfer from the near-by testicular artery to the PVP

* In some females, the utero-ovarian vein and the ovarian artery form a counter-current exchange system

* In some females, PGF2-alpha is transferred from the utero-ovarian vein to the ovarian artery

* The arctic fox uses CCE to keep its feet from freezing


EL

* CCE in reproductive biology

* Figures for above link

* The arctic fox and CCE

* PVP in male

* CCE

* Image of CCE