Friday, September 2, 2011


Today, learnalittle has brains on the brain.

The brain is the central component of the nervous system, governing every thought and function in our body. This magnificent organ is enclosed in the cranium, protected by cerebrospinal fluid and a membrane system called the meninges. The brain itself is composed of two hemispheres that control opposite sides of the body (the left hemisphere governs the right side), joined in the middle by the corpus callosum – a thick bundle of fibers that allows the hemispheres to communicate.

There are three basic segments of the brain. The forebrain (the cauliflower-looking, “main” part of the brain) further divides in to the telencephalon and diencephalon; the telencephalon – or cerebrum – is composed of four lobes. The occipital lobe – found at the base of the forebrain – deals in visual processing and dream formation. Above the occipital lobe, the parietal lobe integrates sensory information from many sources, and handles knowledge of numbers and their relations, and object manipulation.

Below the parietal lobe, the temporal lobe controls auditory processing, as well as language semantics; Wernicke’s area – which spans the temporal and parietal lobes – is vital in understanding both writing and speech. The temporal lobe also houses the hippocampus (Latin for “seahorse,” due to it’s shape), a key structure in the formation and consolidation of memory. Henry Gustav Molaison – better known as HM – became neuroscience’s most famous case studies after 2/3 of his hippocampus was removed, causing life long anterograde amnesia (and inability to form new memories). HM also lost both amygdalae, which govern the processing and memory of emotional reactions. The hippocampus and amygdala are the main components of the limbic system, a group of structures for learning and memory.

Finally, the frontal lobe is the foremost area of the brain, implicated in retaining the longer term memories derived from the limbic system, and essential for executive functioning like planning, considering consequences, and suppress social unacceptable behavior. In humans, the frontal lobe is much bigger than the majority of mammals, and continues developing into the early 20’s – which is why teenagers are more prone to ill-advised decisions.

The second component of the forebrain is the diencephalon (or interbrain), a cluster of structures encased within telencephalon. Notable diencephalon components include the thalamus – which relays information to the above-mentioned lobes and regulates sleep and wakefulness – and the hypothalamus – which helps control body temperature, hunger, and circadian cycles.

Together, the midbrain and hindbrain make up the brainstem, which regulates many bodily reflexes, homeostatic functions, and involuntarily processes. For example, the hindbrain’s pons helps monitor swallowing, bladder control, and posture, while the medulla oblongata is involved in respiration, heartbeat, and blood pressure. The hindbrain also includes the cerebellum (the small, crumpled looking mass below the cerebrum), which primarily deals in motor control, but may have some role in fear and pleasure response.

Considering how much the brain does for you it, show your thanks by using it well and often.

Source: 1, 2, 3, 4, 5