The Nikon MicroscopyU confocal microscopy image gallery was created with a PCM-2000 confocal scanning system interfaced to a Nikon Eclipse E600 upright microscope. Images were recorded in successive z-axis serial sections with C-Imaging Systems software with excitation illumination provided by an argon-ion and/or a helium-neon laser.

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Return to the first confocal sequence of frog artery cells.

Arteries are blood vessels that convey blood away from the heart so that the fluid can be distributed throughout the body. Heart or cardiac muscle has the unique feature of initiating its own rhythmic contractions without requiring stimulation from any other source. This type of muscle is referred to as autorhythmic and is typically found in other types of smooth muscle located in the intestine and uterus. In the frog heart, the specialized bundle responsible for initiating heart contraction is the sinus venosus. This pacemaker is comprised of a thin-walled sac that receives blood from the veins and empties into the right atrium. Highly permeable to sodium and calcium molecules carrying a charge, the pacemaker is able to fire an electric current and initiate a heartbeat.