Villi e microvilli in our bowels. Villi increase the internal surface area of the intestinal walls. Increased surface area allows for increased intestinal wall area that is available for absorption. Increased absorptive area is useful because digested nutrients (including monosaccharide and amino acids) pass into the semipermeable villi through diffusion.
Immune system fighting a cancer cell. A killer T-lymphocyte (orange) inducing a cancer cell to undergo Programmed Cell Death.
human chromosomes, showing centromeres and chromatids
Intestinal villi. Coloured scanning electron micrograph (SEM) of villi on the lining of the small intestine. Villi are finger-like projections that line the surface of the small intestine and increase the surface area available for the absorption of nutrients from digested food. Magnification: x135 when printed 10 centimetres wide.
Retina. Coloured scanning electron micrograph (SEM) of rods (yellow) and cones (green) in the retina of the eye. The outer nuclear layer is purple. Magnification x1800 when printed at 10 centimetres wide. [F0010041] Incredible!!
currentsinbiology: “ infinity-imagined: “ Mitosis, Neurons, and the DNA replication complex. ” They are all cool but I can’t help personifying the neuron in the middle - seems to be trying to make friends with everyone. ”
Peyer's patches (green), coloured scanning electron micrograph (SEM). These regions of lymphoid tissue are found in the human intestine, usually in the ileum, the final section of the small intestine.
Helicobacter pylori. Coloured transmission electron micrograph (TEM) of a Helicobacter pylori bacterium (formerly known as Campylobacter pyloridis). Colonies of H.pylori occur on the stomach mucous membrane in people suffering gastritis, and this bacteria has been linked to stomach ulcer formation.
T-bacteriophages chomping on E. coli [69000x magnification]