What structure arises from the ectoderm germ layer?

The development of the human body begins with three primary germ layers: the ectoderm, mesoderm, and endoderm. Each germ layer gives rise to specific types of tissues and organs.

The ectoderm, which is the outermost layer, is responsible for forming structures that include the integumentary system (skin) and nervous system. This makes nerve tissue a direct derivative of the ectoderm. In the context of the question, nerve tissue originates from the ectoderm during the process of neurulation, where it develops into the brain and spinal cord, as well as peripheral nerves.

Other choices stem from different germ layers. Skeletal muscles are derived from the mesoderm, which also forms the skeleton, connective tissues, and the circulatory system. Blood cells are primarily produced from hematopoietic stem cells in the mesoderm during embryogenesis. Bone tissue, too, comes from the mesoderm, specifically from mesenchymal cells.

Therefore, the correct answer highlights the association of nerve tissue with the ectoderm, emphasizing its role in the formation of the nervous system, which is essential for many body functions.