Nervenfaserbündel

Nervenfaserbündel, also known as fascicles, are bundles of nerve fibers, or axons, found within peripheral nerves. These axons are extensions of nerve cells, or neurons, and are responsible for transmitting electrical and chemical signals throughout the nervous system. Within a nerve, individual axons are grouped together into fascicles, which are then surrounded by a layer of connective tissue called the perineurium.

Each fascicle contains many axons, and these axons can be either myelinated or unmyelinated. Myelinated axons are covered by a fatty sheath called myelin, which acts as an insulator and speeds up nerve impulse conduction. Unmyelinated axons lack this sheath and conduct signals more slowly. The arrangement of axons within a fascicle can vary, and different fascicles within the same nerve may contain a mix of sensory and motor axons, or axons destined for different target organs.

The perineurium surrounding each fascicle provides structural support and helps to protect the axons from mechanical injury. It also plays a role in maintaining the ionic environment around the axons, which is crucial for nerve impulse transmission. Larger peripheral nerves often contain multiple fascicles, and the overall structure of a nerve is determined by the number and organization of these fascicles, as well as the epineurium, an outer layer of connective tissue that encloses the entire nerve. Damage to a nerve fiber bundle can lead to a loss of function in the area innervated by those axons, such as muscle weakness or sensory deficits.