Term:brain

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OVERVIEW OF NOUN BRAIN

1) brain, encephalon: that part of the central nervous system that includes all the higher nervous centers; enclosed within the skull; continuous with the spinal cord

Image of brain
Image of brain

2) brain, brainpower, learning ability, mental capacity, mentality, wit: mental ability; “he’s got plenty of brains but no common sense

3) mind, head, brain, psyche, nous: that which is responsible for one’s thoughts and feelings; the seat of the faculty of reason; “his mind wandered”; “I couldn’t get his words out of my head

4) genius, mastermind, brain, brainiac, Einstein: someone who has exceptional intellectual ability and originality; “Mozart was a child genius”; “he’s smart but he’s no Einstein”

5) brain: the brain of certain animals used as meat

OVERVIEW OF VERB BRAIN

1) brain: hit on the head

2) brain: kill by smashing someone’s skull

noun brain has 5 sense(s) (first 4 from tagged texts)


brain (Wikipedia)
This article is about the brains of all types of animals, including humans. For information specific to the human brain, see Human brain. For other uses, see Brain (disambiguation).
A brain floating in a liquid-filled glass jar. Yellowing of the handwritten labels on the jar give the object an antique appearance.
A chimpanzee brain

The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. Only a few invertebrates such as sponges, jellyfish, adult sea squirts and starfish do not have a brain; diffuse or localised nerve nets are present instead. The brain is located in the head, usually close to the primary sensory organs for such senses as vision, hearing, balance, taste, and smell. The brain is the most complex organ in a vertebrate's body. In a typical human, the cerebral cortex (the largest part) is estimated to contain 15–33 billion neurons, each connected by synapses to several thousand other neurons. These neurons communicate with one another by means of long protoplasmic fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body targeting specific recipient cells.

Physiologically, the function of the brain is to exert centralized control over the other organs of the body. The brain acts on the rest of the body both by generating patterns of muscle activity and by driving the secretion of chemicals called hormones. This centralized control allows rapid and coordinated responses to changes in the environment. Some basic types of responsiveness such as reflexes can be mediated by the spinal cord or peripheral ganglia, but sophisticated purposeful control of behavior based on complex sensory input requires the information integrating capabilities of a centralized brain.

The operations of individual brain cells are now understood in considerable detail but the way they cooperate in ensembles of millions is yet to be solved. Recent models in modern neuroscience treat the brain as a biological computer, very different in mechanism from an electronic computer, but similar in the sense that it acquires information from the surrounding world, stores it, and processes it in a variety of ways, analogous to the central processing unit (CPU) in a computer.

This article compares the properties of brains across the entire range of animal species, with the greatest attention to vertebrates. It deals with the human brain insofar as it shares the properties of other brains. The ways in which the human brain differs from other brains are covered in the human brain article. Several topics that might be covered here are instead covered there because much more can be said about them in a human context. The most important is brain disease and the effects of brain damage, covered in the human brain article because the most common diseases of the human brain either do not show up in other species, or else manifest themselves in different ways.

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