There are no people with two heads, since it is incompatible with life. The most similar anatomical situation is that of Siamese twins, monozygotic twins – the product of the same fertilized ovum – whose embryos fail to separate completely during fetal development, due to a congenital mutation. The result is the birth of two babies joined by some part of the body: by the back (pygópagos), by the lower pelvis (ischiopagus), by the head (craniopagus) … Normally, the Siamese share organs, such as the liver and the urogenital apparatus. The nervous systems of one and the other are usually almost or completely separate , which implies that each brother has his own sensations, emotions and cognitive faculties.
Are there double-headed people?
How is a bone marrow transplant performed?
Bone marrow transplants, how can I donate? What requirements do I need to meet? How many types of donations are there?
The most common diseases of the nervous system
Made up of the brain, spinal cord, and nerves, it becomes the body's communication system that controls much of what we do. It allows us to breathe, walk, speak, swallow, and learn. And, in addition, it controls how we react in an emergency.
Bumps to the head can trigger neurodegenerative diseases
Suffering repeated blows to the head during youth can promote the development of neurodegenerative diseases such as Alzheimer's in the long term, according to the results of a study conducted by the Boston University School of Medicine (United States).
A Cambrian nervous system to frame
It belongs to an ancestor of crustaceans and insects that lived more than 500 million years ago and has a degree of detail never seen before.
The signals that make up the nervous system in the embryo
Researchers from the Higher Council for Scientific Research, CSIC, have determined which are the signals that make possible the formation of the central and peripheral nervous system during the embryonic period. The advance will allow the study of some serious disorders that can occur in the development of the human embryo.