The document discusses the brain and nervous system. It notes that as long as the brain remains a mystery, so too will the universe. It then provides details on the two main types of cells in the central nervous system - neurons, which transmit nervous messages, and glial cells, which assist neurons. The brain contains over 100 billion neurons. Some axons are wrapped in a myelin sheath formed by Schwann cells, which allows signals to jump between nodes and travel hundreds of times faster than unmyelinated axons.
ICT Role in 21st Century Education & its Challenges.pptx
The nervous system
1. “Mientras el cerebro sea un misterio, el
Universo continuará siendo un misterio.”
(Santiago Ramón y Cajal, Petilla de Aragón
1852-Madrid,1934. Premi Nobel de Medicina
1906)
2.
3. Two kind of cells:Neurones and glial cells.
NEURONES are the ones that trasmit the nervous
message.
GLIAL CELLS assist the neurones in the CNS.
Nerve Cells and Astrocyte (SEM
x2,250). This image is copyright
Dennis Kunkel at
www.DennisKunkel.com, used
with permission.
6. Some axons are wrapped in a myelin sheath formed by
specialized glial cells known as Schwann cells.
The gap between Schwann cells is known as the node of
Ranvier, and serves as points along the neuron for
generating a signal. Signals jumping from node to node
travel hundreds of times faster than signals traveling along
the surface of the axon. This allows your brain to
communicate with your toes in a few thousandths of a
second
