Darrel B. is a 56-year-old male who was diagnosed with pancreatic cancer two months ago. Because Darrel's cancer has not spread beyond the local tissue of the pancreas, his doctor informs him that he is eligible for surgery to remove the tumor through a Whipple procedure. Darrel undergoes surgery, where his surgeon removes the head of the pancreas, the gall bladder, part of the common bile duct, most of the duodenum, and part of the stomach. The surgeon then connects the remaining portion of the pancreas so that pancreatic enzymes, bile, and the contents from Darrel's stomach will flow directly into the small intestine. Darrel's doctors are confident that the surgery has been successful in removing all of the pancreatic tumor, but emphasizes that he has a long road of recovery after having such a complex surgical procedure. Since a portion of the duodenum was removed during the procedure, Darrel is now missing various elements normally found in the mucosal lining of this portion of the small intestine, including Brunner's glands. What is the function of Brunner's glands in the duodenum

They both determine the exact age of rocks.

Mantle convection  is the slow  creepingmotion of earth's solid silicate  mantle  caused by  convection  currents carrying  heat from the interior  to the planet's surface.[1][2]  the earth's surface  lithosphere, which rides atop the  asthenosphere  (the two components of the  upper mantle), is divided into a number of  plates  that are continuously being created and consumed at their opposite  plate boundaries. accretion occurs as mantle is added to the growing edges of a plate, associated with  seafloor spreading. this hot added material cools down by  conduction  and  convection  of heat. at the consumption edges of the plate, the material has thermally contracted to become dense, and it sinks under its own weight in the process of  subduction  usually at an  ocean trench.[3]this subducted material sinks through the earth's interior. some subducted material appears to reach the lower mantle,[4]  while in other regions, this material is impeded from sinking further, possibly due to a phase transition from  spinel  to  silicate perovskiteand  magnesiowustite, an  endothermic reaction.[5]the subducted oceanic crust triggers  volcanism, although the basic mechanisms are varied. volcanism may occur due to processes that add buoyancy to partially melted mantle causing an upward flow due to a decrease in density of the partial melt.secondary forms of convection that may result in surface volcanism are postulated to occur as a consequence of intraplate extension[6]  and  mantle plumes.[7]it is because the mantle can convect that the  tectonic plates  are able to move around the earth's surface.[8]mantle convection seems to have been much more active during the  hadean  period, resulting in gravitational sorting of heavier molten  iron, and  nickel  elements and  sulphides  in the core, and lighter  silicate minerals  in the  mantle.

Atissue is a group of connected cells that have a similar function within an organism.