Cisterna

A cisterna (plural cisternae) refers to a flattened membrane disk that makes up the Golgi apparatus. A typical Golgi has multiple stacks of anywhere from 3 to 7 cisternae (usually around 6) stacked upon each other like pancakes. The cisternae carry Golgi enzymes to help or to modify cargo proteins traveling through them destined for other parts of the cell.

The cisternae also carry structural proteins important for their maintenance as flattened membranes and their stacking upon each other.

The earliest cisternae are called the cis-cisternae, followed by the medial cisternae, then the trans-cisternae (as they move away from the endoplasmic reticulum).

The location of formation of new cisternae is often called the cis-Golgi network, and the end of the Golgi where transport to other parts of the cell occurs is called the trans-Golgi network. Both are thought to be specialized cisternae leading in and out of the Golgi Complex.

Cisternae may also refer to flattened regions of the rough endoplasmic reticulum.