celkroppar

Celkroppar, or cell bodies, are the central part of a cell that contains the nucleus and most of the cytoplasm. In the nervous system the term most often refers to the soma of a neuron—the region from which dendrites extend and the axon originates. Other cell types have cell bodies, but neuronal celkroppar are typically large and metabolically active.

The nucleus is usually round to oval with a prominent nucleolus. The cytoplasm contains rough endoplasmic reticulum organized into Nissl bodies, which synthesize proteins required by the neuron. Mitochondria, the Golgi apparatus, lysosomes, and vesicles support energy production and protein processing. The cytoskeleton, including neurofilaments, maintains shape and supports transport within the cell. The plasma membrane encloses all these components and communicates with surrounding cells.

Location and role: In the central nervous system, neuronal celkroppar are typically located in the gray matter of the brain and spinal cord. In the peripheral nervous system, they reside in sensory, autonomic, and other ganglia. Functionally, the soma integrates synaptic inputs from dendrites, regulates gene expression, and provides the materials needed to maintain axons and dendrites.

Size varies considerably; neuronal celkroppar commonly range from about 4 to 100 micrometers in diameter. Pathologically, changes in the cell body reflect nerve cell stress or degeneration and can include swelling, chromatolysis, or loss of neurons in disease.