The brain is the center of the nervous system The nervous system is a network of specialized cells that communicate information about an organism's surroundings and itself. It processes this information and causes reactions in other parts of the body. It is composed of neurons and other specialized cells called glial cells that aid in the function of the neurons. The nervous system is divided in all vertebrate Vertebrates are members of the subphylum Vertebrata, chordates with backbones or spinal columns. About 58,000 species of vertebrates have been described. Vertebrata is the largest subphylum of chordates, and contains many familiar groups of large land animals. Vertebrates comprise cyclostomes, bony fish, sharks and rays, amphibians, reptiles,, and most invertebrate An invertebrate is an animal without a vertebral column Also known as the spine or backbone. The group includes 95% of all animal species — all animals except those in the Chordate subphylum Vertebrata, animals. Some primitive animals such as jellyfish Cnidaria is a phylum containing over 9,000 species of animals found exclusively in aquatic, mostly marine, environments. Their distinguishing feature is cnidocytes, specialized cells that they use mainly for capturing prey. Their bodies consist of mesoglea, a non-living jelly-like substance, sandwiched between two layers of epithelium that are and starfish Echinoderms are a phylum of marine animals. Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone. Aside from the problematic Arkarua, the first definitive members of the phylum appeared near the start of the Cambrian period have a decentralized nervous system without a brain, while sponges Sponges are animals of the phylum Porifera . Their bodies consist of jelly-like mesohyl sandwiched between two thin layers of cells. While all animals have unspecialized cells that can transform into specialized cells, sponges are unique in having some specialized cells that can transform into other types, often migrating between the main cell lack any nervous system at all. In vertebrates, the brain is located in the head, protected by the skull The skull is a bony structure found in the head of many animals. The skull supports the structures of the face and protects the head against injury and close to the primary sensory apparatus of vision Visual perception is the ability to interpret information and surroundings from visible light reaching the eye. The resulting perception is also known as eyesight, sight or vision. The various physiological components involved in vision are referred to collectively as the visual system, and are the focus of much research in psychology, cognitive, hearing Hearing is one of the traditional five senses. It is the ability to perceive sound by detecting vibrations via an organ such as the ear. The inability to hear is called deafness, balance Equilibrioception or sense of balance is one of the physiological senses. It helps prevent humans and animals from falling over when walking or standing still, taste Taste is a form of direct chemoreception and is one of the traditional five senses. It refers to the ability to detect the flavor of substances such as food, certain minerals, and poisons. In humans and many other vertebrate animals the sense of taste partners with the less direct sense of smell, in the brain's perception of flavor. In the West,, and smell Olfaction refers to the sense of smell. This sense is mediated by specialized sensory cells of the nasal cavity of vertebrates, and, by analogy, sensory cells of the antennae of invertebrates. For air-breathing animals, the olfactory system detects volatile or, in the case of the accessory olfactory system, fluid-phase chemicals. For water-.
Brains can be extremely complex. The cerebral cortex The cerebral cortex is a structure within the brain that plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It constitutes the outermost layer of the cerebrum. In preserved brains, it has a grey color, hence the name "grey matter". Grey matter is formed by neurons and their unmyelinated of the human brain The human brain is the center of the human nervous system and is a highly complex organ. Enclosed in the cranium, it has the same general structure as the brains of other mammals, but is over three times as large as the brain of a mammal with an equivalent body size. Most of the expansion comes from the cerebral cortex, a convoluted layer of contains roughly 15-33 billion neurons A neuron (pronounced /ˈnjʊərɒn/ NOOR-on, also known as a neurone or nerve cell) is an excitable cell in the nervous system that processes and transmits information by electrochemical signalling. Neurons are the core components of the brain, the vertebrate spinal cord, the invertebrate ventral nerve cord, and the peripheral nerves. A number of depending on gender and age[1], linked with up to 10,000 synaptic Chemical synapses are specialized junctions through which neurons signal to each other and to non-neuronal cells such as those in muscles or glands. Chemical synapses allow neurons to form circuits within the central nervous system. They are crucial to the biological computations that underlie perception and thought. They allow the nervous system connections each. Each cubic millimeter of cerebral cortex contains roughly one billion synapses.[2] These neurons communicate with one another by means of long protoplasmic fibers called axons An axon or nerve fiber is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body or soma, which carry trains of signal pulses called action potentials An action potential is a transient alteration of the transmembrane voltage (or membrane potential) across an excitable membrane generated by the activity of voltage-gated ion channels embedded in the membrane. Action potentials play multiple roles in several types of excitable cells such as neurons, myocytes, and electrocytes. The best known to distant parts of the brain or body and target them to specific recipient cells.
The most important biological function of the brain is to generate behaviors that promote the welfare of an animal. Brains control behavior either by activating muscles, or by causing secretion of chemicals such as hormones. Even single-celled organisms may be capable of extracting information from the environment and acting in response to it.[3] Sponges, which lack a central nervous system, are capable of coordinated body contractions and even locomotion.[4] In vertebrates, the spinal cord by itself contains neural circuitry capable of generating reflex responses as well as simple motor patterns such as swimming or walking.[5] However, sophisticated control of behavior on the basis of complex sensory input requires the information-integrating capabilities of a centralized brain.
Despite rapid scientific progress, much about how brains work remains a mystery. The operations of individual neurons and synapses are now understood in considerable detail, but the way they cooperate in ensembles of thousands or millions has been very difficult to decipher. Methods of observation such as EEG Electroencephalography is the recording of electrical activity along the scalp produced by the firing of neurons within the brain. In clinical contexts, EEG refers to the recording of the brain's spontaneous electrical activity over a short period of time, usually 20–40 minutes, as recorded from multiple electrodes placed on the scalp. In recording and functional brain imaging Neuroimaging includes the use of various techniques to either directly or indirectly image the structure, function/pharmacology of the brain. It is a relatively new discipline within medicine and neuroscience/psychology tell us that brain operations are highly organized, but these methods do not have the resolution to reveal the activity of individual neurons.[6]
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TTh 9 30 10 50 SSL 105 Fall 2004 Check us out Click the brain above
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Infectious agent which leads to chronic wasting disease is spread through feces, according to study.
