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 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 Cell Body: Center of the cell, contains the basic biological machinery that keeps the neuron alive Dendrite: receiving end of the neuron Dendrite: receiving end of the neuron

The Brain (continued) Axon: Transmits information to other neurons Axon: Transmits information to other neurons Terminal Buttons: located at the end of the axon and release chemicals called neurotransmitters Terminal Buttons: located at the end of the axon and release chemicals called neurotransmitters Neurotransmitters: Messengers that carry information to nearby neurons Neurotransmitters: Messengers that carry information to nearby neurons

The Brain (continued) The cortex consists of left and right halves called hemispheres The cortex consists of left and right halves called hemispheres Corpus Callosum: Thick bundles of neurons Corpus Callosum: Thick bundles of neurons Frontal Cortex: Personality and ability to make and carry out plans Frontal Cortex: Personality and ability to make and carry out plans

Hemispheres Right Non verbal tasks Non verbal tasks Listening to music Listening to music Visual and spatial aspects Visual and spatial aspects Creativity CreativityLeft Language processing Language processing Logical thinking such as math Logical thinking such as math Speech Speech Reading Reading Writing Writing

The Making of the Brain Brain weighs three quarters of a pound at birth Brain weighs three quarters of a pound at birth Brain weight at birth is 25% of the weigh of the adult brain Brain weight at birth is 25% of the weigh of the adult brain Age three- brain has reached 80% of ultimate weight 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 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 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 Neurons begin to produce ten weeks after conception By 28 weeks almost all neurons are produced By 28 weeks almost all neurons are produced Neurons are formed at 4,000 per second Neurons are formed at 4,000 per second

Myelin In the fourth month of pre-natal development axons begin to acquire myelin In the fourth month of pre-natal development axons begin to acquire myelin Myelin: The fatty wrap that speeds neural transmission Myelin: The fatty wrap that speeds neural transmission The process continues through adolescence The process continues through adolescence The more myelin one has improves their coordination and reaction times 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 Months after birth axons and dendrite grow longer and dendrites sprout new limbs As dendrites increase synapses increase As dendrites increase synapses increase Synaptic Pruning: Synapses begin to disappear gradually Synaptic Pruning: Synapses begin to disappear gradually Brain downsizes, weeding out unnecessary connections between neurons Brain downsizes, weeding out unnecessary connections between neurons Usually occurs after time of first birthday 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 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 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 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) 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 Neuroplasticity: the extent to which brain organization is flexible Organization of the brain function is thought to be predetermined genetically Organization of the brain function is thought to be predetermined genetically The recovery of brain functions are not uncommon and proves the plasticity The recovery of brain functions are not uncommon and proves the plasticity