Electron micrograph of a thin section through a portion of the chloroplast of the unicellular green alga Chlamydomonas. Free ribosomes are seen as dark particles within the chloroplast stroma. They ar...

Transmission electron micrograph of a discontinuous endothelium in a capillary from a guinea pig pancreas. There is a red blood cell in the capillary lumen and a pericyte under the endothelium. Imag...

Transmission electron micrograph showing exocytosis in guinea pig pancreas. Image made available by James D. Jamieson and the Department of Cell Biology, Yale University School of Medicine.

Transmission electron micrograph depicting exocytosis in a rat pancreas. Image made available by James D. Jamieson and the Department of Cell Biology, Yale University School of Medicine.

Transmission electron micrograph showing a vesicle fusing with a duct lumen in a rat pancreas. Image made available by James D. Jamieson and the Department of Cell Biology, Yale University School of ...

Transmission electron micrograph of a section of the right atrium of a guinea pig heart. A portion of nucleus is seen at far left, with two centrioles close to the nuclear envelope. A region of myofib...

Transmission electron micrograph of longitudinal section of rat heart cardiac muscle from the atrium. A darkly stained intercalated disc runs from upper left to lower right. Also prominent are groups...

Transmission electron micrograph of longitudinal section of rat cardiac muscle from the heart atrium. Homogeneously staining spherical trial granules are present as well as mitochondria and myofibrils...

Transmission electron micrograph of longitudinal section of a a rat heart ventricle. Ordered arrays of myofibrils are interspersed with rows of mitochondria. Small, darkly staining glycogen granules a...

Transmission electron micrograph of nerve cell terminals on medulla dendrites. The body of the dendrite (lower part of image) contains aligned microtubules (neurotubule). Synapses are seem on the den...