What distinct feature defines myelomeningocele?

Myelomeningocele is a type of spina bifida characterized by the malformation of the spinal cord and its surrounding tissues. The distinctive feature of myelomeningocele is that there is protrusion of the spinal cord and its nerves through the vertebrae, leading to exposure beyond the skin. This exposure can result in significant neurological deficits and susceptibility to infection due to the lack of protective coverings over the spinal cord in the affected area.

The condition is comprised of both the neural tissue and the meninges, which means that the crucial elements of the spinal cord are not merely covered but instead are malformed and exposed. This is in stark contrast to other conditions, where the spinal cord may be intact but the meninges might be exposed or covered. Thus, the correct answer accurately reflects the essential characteristics of myelomeningocele and emphasizes the severity of the condition in terms of potential health complications.