Download The Emerging Nervous System

The Emerging Nervous System
By:
Briana and Alexandra
The Brain
• Neuron: The basic unit in the brain and the
rest of the nervous system that specializes in
receiving and transmitting information
• Cell Body: Center of the cell, contains the
basic biological machinery that keeps the
neuron alive
• Dendrite: receiving end of the neuron
The Brain (continued)
• Axon: Transmits
information to other
neurons
• Terminal Buttons: located
at the end of the axon and
release chemicals called
neurotransmitters
• Neurotransmitters:
Messengers that carry
information to nearby
neurons
The Brain (continued)
• The cortex consists of left and right
halves called hemispheres
• Corpus Callosum: Thick bundles of
neurons
• Frontal Cortex: Personality and ability to
make and carry out plans
Hemispheres
Right
• Non verbal tasks
• Listening to music
• Visual and spatial
aspects
• Creativity
Left
• Language processing
• Logical thinking such as
math
• Speech
• Reading
• Writing
The Making of the Brain
• Brain weighs three quarters of a pound at
birth
• Brain weight at birth is 25% of the weigh of
the adult brain
• Age three- brain has reached 80% of ultimate
weight
Neurons
• Neural Plate: A group of cells
that form a flat structure
three weeks after conception
• At four weeks the neural
plate folds to form a tube
that than becomes the brain
and spinal cord
• Neurons begin to produce
ten weeks after conception
• By 28 weeks almost all
neurons are produced
• Neurons are formed at 4,000
per second
Myelin
• In the fourth month of
pre-natal development
axons begin to acquire
myelin
• Myelin: The fatty wrap
that speeds neural
transmission
• The process continues
through adolescence
• The more myelin one
has improves their
coordination and
reaction times
Emerging Brain Structures
• Months after birth axons and dendrite grow
longer and dendrites sprout new limbs
• As dendrites increase synapses increase
• Synaptic Pruning: Synapses begin to
disappear gradually
• Brain downsizes, weeding out unnecessary
connections between neurons
• Usually occurs after time of first birthday
Studies on the Brain
• Children who suffer brain injuries help to provide
information on brain structure and function
• Studies of Electrical Activity: metal electrodes are
placed on an infants scalp and produce a pattern of
brain waves
• Functional Magnetic Resonance Imaging: Uses
magnetic fields to track the flow of blood in the
brain
PET SCANS
• PET Scans: used
sparingly – requires
children to be injected
with radioactive form
of glucose and to lie
still for several minutes
(can be potentially
hazardous)
Brain Plasticity
• Neuroplasticity: the extent to which brain
organization is flexible
• Organization of the brain function is thought
to be predetermined genetically
• The recovery of brain functions are not
uncommon and proves the plasticity