September 26 2013
1861 Broca, french surgeon. Patient could not speak but could understand everything. There was a lesion on the
left side of the brain. Now called Broca's area, it is where speech is produced.
Wernicke's area is related to comprehension of language.Are our hemispheres specialized ? Surgeon cut the
corpus collosum, that connects both hemisphere.And split brains patients looked normal.
Video ** Guy with split brain, verbal and drawings and faces. Left is speech and communication, as well as
reasoning. Right is for face recognition and visual abilities.
Neurons are the basic units of the nervous system. Neurons are cells that specialize in communication. They
operate through electrical impulses and communicate with other neurons through chemical signals.
Neurons have different shapes and sizes, but they typically share some common features:
**Video babies and neurons.
Dendrites: branchlike extensions of the neuron that receive information from other neurons.
Cell body (soma): Main part of the neuron, contains nucleus. This is where information from other neurons is
collected and integrated.
Axon: Once the incoming information has been integrated in the cell body, electrical impulses are transmitted
along a long narrow fibre to other neurons or to muscles or glands. Many axons are wrapped with a special
substance called myelin. This myelin sheath speeds up the transmission of signals that move along the axon.
Terminal Buttons: Small knobs at the ends of axons that release chemical signals from the neuron to an area
called the synapse.
Synapse: is a junction (tiny gap) where chemical signals, neurotransmitters are transmitted from one neuron to
the other one.
What is the neural impulse exactly? Acomplex electrochemical reaction. Both inside and outside of the neuron are fluids. There are negatively and
positively charged ions in that fluid. When not active, inside of the neuron is negatively charged. This is called the
resting potential. When neuron is stimulated, balance of the electrical charge changes and it creates an action
potential, an electrical charge or a neural impulse that passes along the axon.
Neurons are like guns. It either fires or it does not. And their action potential, electrical charge is always the same
size. Intensity is coded in two ways:
-the number of neurons firing (