AP BIOLOGY

Detailed explanation-1: -A myelin sheath is a sleeve (sheath) that’s wrapped around each nerve cell (neurons). It’s a protective layer of fat (lipids) and protein that coats the main “body” section of a neuron called the axon.

Detailed explanation-2: -Are all axons covered with myelin? No; they can be either myelinated or unmyelinated. Myelinated axons are ensheathed along their entire length. The axon caliber (diameter) in mammalian PNS ranges from 0.1 m to 20 m, with unmyelinated axons being less than 2 m and myelinated axons being more than 1–2 m in diameter.

Detailed explanation-3: -Myelin is an insulating layer, or sheath that forms around nerves, including those in the brain and spinal cord. It is made up of protein and fatty substances. This myelin sheath allows electrical impulses to transmit quickly and efficiently along the nerve cells.

Detailed explanation-4: -Myelin sheath provides an insulating layer to the dendrites. Axons carry the signal from the soma to the target.