Neuron All neurons are electrically excitable, maintaining voltage gradients across their membranes by means of metabolically driven ion pumps, which combine with ion channels embedded in the membrane to generate intracellular-versus-extracellular concentration differences of ions such as sodium, potassium, chloride, and calcium. Changes in the cross-membrane voltage can alter the function of voltage-dependent ion channels. If the voltage changes by a large enough amount, an all-or-none electrochemical pulse called an action potential is generated, which travels rapidly along the cell's axon, and activates synaptic connections with other cells when it arrives. Neurons do not undergo cell division. Overview[edit] A neuron is a specialized type of cell found in the bodies of all eumetozoans. Although neurons are very diverse and there are exceptions to nearly every rule, it is convenient to begin with a schematic description of the structure and function of a "typical" neuron. Polarity[edit]
Diffusion MRI Diffusion MRI (or dMRI) is a magnetic resonance imaging (MRI) method which came into existence in the mid-1980s.[1][2][3] It allows the mapping of the diffusion process of molecules, mainly water, in biological tissues, in vivo and non-invasively. Molecular diffusion in tissues is not free, but reflects interactions with many obstacles, such as macromolecules, fibers, membranes, etc. Water molecule diffusion patterns can therefore reveal microscopic details about tissue architecture, either normal or in a diseased state. The first diffusion MRI images of the normal and diseased brain were made public in 1985.[4][5] Since then, diffusion MRI, also referred to as diffusion tensor imaging or DTI (see section below) has been extraordinarily successful. Its main clinical application has been in the study and treatment of neurological disorders, especially for the management of patients with acute stroke. Diffusion[edit] Given the concentration and flux where D is the diffusion coefficient. .
Khan Academy - BRAINTEASERS neurotransmitters and neuromodulators The soft warm living substance of the brain and nervous system stands in stark contrast to the rigid metal and plastic hardware of a modern day computer, but at the fundamental level there are clear similarities between these two apparently disparate organizational systems and, of course, one is a product of the other. Not only are the nerve cell units (neurons) self-repairing and self-wiring under the grand design built into our genes, but they can also promote, amplify, block, inhibit, or attenuate the micro-electric signals which are passed to them, and through them. In this way they give rise to signalling patterns of myriad complexity between networks of cerebral neurons, and this provides the physical substrate of mind. These key processes of signalling by one group, or family, of neurons to another is achieved largely by the secretion of tiny quantities of potent chemical substances by neuronal fibre terminals. In this way, the nerve impulses are passed on from cell to cell. 1.
Multitasking: This Is Your Brain On Media From Rasmussen College, Multitasking: This Is Your Brain On Media is a cool infographic design that looks at some of the research behind multitasking. New reports find that multi-taskers are “lousy at everything that’s necessary for multi-tasking.” Considering the amount of time people spend with around-the-clock access to TV, the Internet and mobile devices, it’s not surprising.This infographic looks at the causes and effects of multi-tasking. From a design perspective, I like the clean look with a simple color palate that is easy on the eyes. The statistics in the Media Addiction section could have been visualized to make them easier to comprehend. I love the brain diagrams. Found on Infographics Journal
Brain Atlas - Introduction The central nervous system (CNS) consists of the brain and the spinal cord, immersed in the cerebrospinal fluid (CSF). Weighing about 3 pounds (1.4 kilograms), the brain consists of three main structures: the cerebrum, the cerebellum and the brainstem. Cerebrum - divided into two hemispheres (left and right), each consists of four lobes (frontal, parietal, occipital and temporal). The outer layer of the brain is known as the cerebral cortex or the ‘grey matter’. – closely packed neuron cell bodies form the grey matter of the brain. Cerebellum – responsible for psychomotor function, the cerebellum co-ordinates sensory input from the inner ear and the muscles to provide accurate control of position and movement. Brainstem – found at the base of the brain, it forms the link between the cerebral cortex, white matter and the spinal cord. Other important areas in the brain include the basal ganglia, thalamus, hypothalamus, ventricles, limbic system, and the reticular activating system. Neurons
Functional magnetic resonance imaging Researcher checking fMRI images Functional magnetic resonance imaging or functional MRI (fMRI) is a functional neuroimaging procedure using MRI technology that measures brain activity by detecting associated changes in blood flow.[1] This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. When an area of the brain is in use, blood flow to that region also increases. The primary form of fMRI uses the Blood-oxygen-level dependent (BOLD) contrast,[2] discovered by Seiji Ogawa. The procedure is similar to MRI but uses the change in magnetization between oxygen-rich and oxygen-poor blood as its basic measure. FMRI is used both in the research world, and to a lesser extent, in the clinical world. Overview[edit] The fMRI concept builds on the earlier MRI scanning technology and the discovery of properties of oxygen-rich blood. History[edit] Three studies in 1992 were the first to explore using the BOLD contrast in humans. Physiology[edit]
Morality Quiz/Test your Morals, Values & Ethics - Your Morals.Org
Image by Bernd Knoll at the University of Tubingen by kaspervandenberg Dec 23