Page 16 - Handbook of Electronic Assistive Technology

Chapter 1 • Basic Neurosciences With Relevance to Electronic Assistive Technology 3

Basic Neurosciences

Before we concentrate on different health disorders often seen in individuals accessing
electronic assistive technology, it is important to focus on the basics of how we work.
Functionally, the two critical areas for a level of independent life are communication
and mobility.

How the Central Nervous System Is Made –
Neuroembryology

We are all made the same way; how that happens is obviously up to personal practice, but fun-
damentally a sperm and egg get it together, share their nuclear information and start to double
up and double up until a ball of cells is formed – an early embryological blastocyst (Fig. 1-2).
At this early point we differentiate into three fundamental layers of cell type:
• Endoderm (inner) develops into most of our internal organs.
• Mesoderm (middle) develops into muscle and bone.
• Ectoderm (outer) develops into skin and the nervous system.

By the fourth week of foetal development, this ball squashes down to a plate, with
the ectoderm on one side differentiating into a plate of primitive nervous tissue – the

Ectoderm
Neural
plate

Mesodern
Groove
Endoderm Week 4
Tube
Ball of cells Flattens/squashes

Week 11

Week 5

Birth
FIGURE 1-2 Basic embryology of the nervous system� Courtesy of Fig. 2-1 The development of the nervous system.
Barnes, L., Fairhurst, C., 2011. Hemiplegia Handbook for Parent and Professionals. Mackeith Press.