neurons within the brain and spinal cord

Interestingly, neurons with a particular function are found in a predictable location. The neuron is the functional unit of the nervous system and is designed to transmit information between cells. However, nervous system function is mostly a story of the neuron. The nervous system is comprised of an enormous number of cells (over 100 billion), primarily of two types: neurons (the signaling units) and glial cells (the supporting units). The nervous system coordinates voluntary and involuntary actions in the body by sending and receiving information. In this section you will learn about the nervous system and how it controls the body, and perhaps more importantly, as illustrated in Christina’s case, how the nervous system interprets the environment around us. it has no sense of itself” (Sacks, 1985). In her words, she states: “I feel my body is blind and deaf to itself. Strict focus had to be maintained for even the simplest tasks. She found that there was no in between, or gradual change with movement. Gradually over time Christina learned to walk again and to function with the usual business of life, but only with great care in maintaining attention to the particular movement and never at the same level as before. In fact her body would collapse into a heap the minute she closed her eyes.

Because the sense of body positioning is determined by three things: vision, balance organs, and proprioception, which she had lost, Christina learned to control her body with her eyes, but she found that she could do nothing without using her eyes. This integral part of her nervous system had suddenly deteriorated. I feel weird-disembodied.” Essentially, overnight Christina had lost all proprioception: the ability to sense the relative position of body parts.

She exclaimed: “Something awful’s happened, I can’t feel my body. This is the exact situation that Christina found herself in after waking up one morning. What if your arms seemed to wander unless you kept an eye on them. Imagine that you suddenly lost the ability to stand unless you looked down at your feet.

Neurons within the brain and spinal cord