The Modern Brain




This page describes modern perceptions and faculties of the brain. Here you will be able to see what makes the brain tick and what regions of the brain control different faculties of the body and mind
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The Brain The brain is the primary organ associated with the human mind. It is the center of the nervous system and controls the other organs of the body. This control allows the response of our body to the changes in the outer world.

Source: Shepherd, Neurobiology.

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Diagram of the human brain.

Physical Composition
The brain's cellular structure is extremely complex. Most of the brain's cells are glial cells, which hold the organ together. The "working parts" of the brain are its approximately 1010 neurons, a huge network that controls the body and forms the physical basis for thought.




Brain Parts and their Functions


Left Hemisphere - considered more dominant side of the brain; analytical, logical, detail-oriented; usually controls language {1}
Right Hemisphere - dreamier, emotional, processes things in a holistic way rather than breaking them down, more involved with sensory perception than abstract cognition; {1}


Cerebral Cortex - a very thin layer of wrinkled grey tissue that covers the hemispheres of the brain; {3}
Sulcus - a "crevice" in cerebral cortex {3}
Gyrus - a "bulge" on the cerebral cortex {1}
Ventromedial Prefrontal Cortex - "used in regulating cognition and empathetic responses; its central role is in adapting to emotional control, which includes association of mental objects and bodily control" {1}


Cerebellum - "smaller portion on the lower back part of brain; the mammalian ancestor's main brain; a large, convoluted protruberance at the back of the brainstem, essential for coordinating movement and balance" {1}
Cerebrum - larger part of the brain split into two hemispheres, each split into four sections called lobes


Occipital Lobe - "back region of cerebrum; almost entirely a visual processing area" {1}
Temporal Lobe - "lower region on the left and right side of the cerebrum; "deal with sound, speech comprehension (usually left only) and some aspects of memory" {1}
Frontal Lobe - "front region of the cerebrum; deals with most integrated brain functions: thinking, conceptualizing and planning; plays a major part in the conscious appreciation of emotion" {1}
Parietal Lobe - "top region of the cerebrum positioned above the occipital lobe and behind the frontal lobe; deals mainly with functions connected with movement, orientation, touch, calculation and certain types of recognition" {1}


Corpus Callosum - "curved band of tissue towards the middle of the brain in between the two hemispheres; relays information from one hemisphere to the other and vice versa, acting as a bridge between the two hemispheres" {1}
Limbic System - "tissue/module underneath the corpus callosum; unconscious; emotions along with most of the many appetites and urges that direct us to behave in a way that helps us survive" {1}
Thalamus - "relay station for almost all incoming sensory information; sends information to the appropriate part of the brain for further processing" {1}
Hypothalamus - "beneath the thalamus; together with the pituitary gland, constantly adjusts the body to keep it optimally adapted to the environment; vital for temperature regulation, emotion, sexual behavior, and motivation" {1}
Hippocampus - "essential for the laying down of long-term memory; converts short-term memories into long-term" {1}
Amygdala - "in front of hippocampus; place where fear is registered and generated; important for learning associations with emotions and processing emotional information" {1}
Brainstem - "most ancient part of brain (evolved more than 500 million years ago); formed from the nerves that run up from the body via the spinal column; carries information from the body into the brain; various clumps of cells in the brainstem determine the brain's general level of alertness and regulates the vegetative processes of the body (such as breathing, heart-beat and blood pressure)" {1}
Reticular Formation - the core of the brainstem that contains hundreds of small neural networks; it has been described as too complex to study (since the 19th century)





Nervous System (Cellular Level)


Glial Cells
- "relatively simple-looking structures whose main known purpose is to glue the brain together and maintain its physical integrity; also speculated to play a role in amplifying or synchronizing electrical activity within the brain" {1}

Neuron
- "cells that are adapted to carry an electrical signal from one to another; (one in ten of the all cells in the brain);

neuron.JPG

each neuron cell can be connected to up to 10,000 neighboring neurons" {1}

Axon
- one of two types of branches in a neuron; "conducts signals away from the cell nucleus; a long narrow outgrowth of a neuron by which information is transmitted to other neurons" {1}

Dendrite
- second of two types of branches in a neuron; "receives incoming signals from other neurons"

Synapse/Synaptic Cleft - neurotransmitter chemicals being released into the synaptic gap from an axon of one neuron to the dendrite of another neuron during neuron firing; the site for chemical communication between neurons, which contains extracellular fluid

Myelin
- "a sheath of white (mucus like) substance that cover neurons; act as insulation, allowing electricity to flow swiftly and directly along them" {1}




Sources:

{1} Carter, Rita. Mapping the Mind. Los Angeles: University of California, 1998. Print. (pg. 14-17)
{2} Gazzaniga, Michael S., Todd F. Heatherton, and Diane F. Halpern. Psychological Science. Third ed. New York: W. W. Norton, 2008. Print.
{3} http://www.medterms.com/script/main/hp.asp


This site is an interactive site that shows a lot of the structures that Carter talks about throughout the text. It is a sheep brain, but the structures are common to all mammals. You can even select different cross sections of the brain.