What is assistive technology? Assistive technology (AT) is any item, piece of equipment, software program, or product system that is used to increase, maintain, or improve the functional capabilities of persons with disabilities. AT can be low-tech: communication boards made of cardboard or fuzzy felt.
The synthesis and release of chemical substances by cells or glands. Substances secreted include enzymes, hormones, lubricants, surfactants and neurotransmitters. Internal secretion is secretion into the bloodstream. External secretion may be into the intestinal canal or other organs or on to the skin. Compare EXCRETION. 1  the process by which a useful substance produced in a cell is passed through the plasma membrane to the outside.  the substance itself.
#2 Reabsorption - (the transport of water & solutes from the tubular fluid, across the tubular epithelium, into peritubular fluid. #3 Secretion - (the transport of solutes from the peritubular fluid, across the tubular epithelium, & into the tubular fluid).