<P> Villi increase the internal surface area of the intestinal walls making available a greater surface area for absorption . An increased absorptive area is useful because digested nutrients ( including monosaccharide and amino acids ) pass into the semipermeable villi through diffusion , which is effective only at short distances . In other words , increased surface area ( in contact with the fluid in the lumen ) decreases the average distance travelled by nutrient molecules , so effectiveness of diffusion increases . The villi are connected to the blood vessels so the circulating blood then carries these nutrients away . </P>
<P> Villi increase the internal surface area of the intestinal walls making available a greater surface area for absorption . An increased absorptive area is useful because digested nutrients ( including monosaccharide and amino acids ) pass into the semipermeable villi through diffusion , which is effective only at short distances . In other words , increased surface area ( in contact with the fluid in the lumen ) decreases the average distance travelled by nutrient molecules , so effectiveness of diffusion increases . The villi are connected to the blood vessels so the circulating blood then carries these nutrients away . </P>
what purpose do villi serve in the small intestine
what purpose do villi serve in the small intestine
increase the internal surface area of the intestinal walls
increase the internal surface area of the intestinal walls