Central nervous system

The central nervous system (CNS) is the part of the nervous system consisting of the brain and spinal cord. The central nervous system is so named because it integrates information it receives from, and coordinates and influences the activity of, all parts of the bodies of bilaterally symmetric animals — that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish — and it contains the majority of the nervous system. Arguably, many consider the retina and the optic nerve (2nd cranial nerve), as well as the olfactory nerves (1st) and olfactory epithelium as parts of the CNS, synapsing directly on brain tissue without intermediate ganglia. Following this classification the olfactory epithelium is the only central nervous tissue in direct contact with the environment, which opens up for therapeutic treatments. The CNS is contained within the dorsal body cavity, with the brain housed in the cranial cavity and the spinal cord in the spinal canal. In vertebrates, the brain is protected by the skull, while the spinal cord is protected by the vertebrae, both enclosed in the meninges.

Nervous system

The nervous system is the part of an animal's body that coordinates its voluntary and involuntary actions and transmits signals to and from different parts of its body. Nervous tissue first arose in wormlike organisms about 550 to 600 million years ago. In vertebrate species it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS contains the brain and spinal cord. The PNS consists mainly of nerves, which are enclosed bundles of the long fibers or axons, that connect the CNS to every other part of the body. Nerves that transmit signals from the brain are called motor or efferent nerves, while those nerves that transmit information from the body to the CNS are called sensory or afferent. Most nerves serve both functions and are called mixed nerves. The PNS is divided into a) somatic and b) autonomic nervous system, and c) the enteric nervous system. Somatic nerves mediate voluntary movement. The autonomic nervous system is further subdivided into the sympathetic and the parasympathetic nervous systems. The sympathetic nervous system is activated in cases of emergencies to mobilize energy, while the parasympathetic nervous system is activated when organisms are in a relaxed state. The enteric nervous system functions to control the gastrointestinal system. Both autonomic and enteric nervous systems function involuntarily. Nerves that exit from the cranium are called cranial nerves while those exiting from the spinal cord are called spinal nerves.

Alan Walker

Alan Walker may refer to:

See also

Crash Course

Crash Course (also known as Driving Academy) is a 1988 made for television teen film directed by Oz Scott.

Plot

Crash Course centers on a group of high schoolers in a driver’s education class; many for the second or third time. The recently divorced teacher, super-passive Larry Pearl, is on thin ice with the football fanatic principal, Principal Paulson, who is being pressured by the district superintendent to raise driver’s education completion rates or lose his coveted football program. With this in mind, Principal Paulson and his assistant, with a secret desire for his job, Abner Frasier, hire an outside driver’s education instructor with a very tough reputation, Edna Savage, aka E.W. Savage, who quickly takes control of the class.

The plot focuses mostly on the students and their interactions with their teachers and each other. In the beginning, Rico is the loner with just a few friends, Chadley is the bookish nerd with few friends who longs to be cool and also longs to be a part of Vanessa’s life who is the young, friendly and attractive girl who had to fake her mother’s signature on her driver’s education permission slip. Kichi is the hip-hop Asian kid who often raps what he has to say and constantly flirts with Maria, the rich foreign girl who thinks that the right-of-way on the roadways always goes to (insert awesomely fake foreign Latino accent) “my father’s limo”. Finally you have stereotypical football meathead J.J., who needs to pass his English exam to keep his eligibility and constantly asks out and gets rejected by Alice, the tomboy whose father owns “Santini & Son” Concrete Company. Alice is portrayed as being the “son” her father wanted.

Greatest hits album

A greatest hits album, sometimes called a "best of" album or a catalog album, is a compilation of songs by a particular artist or band. Most often the track list contains previously released recordings with a high degree of notability. However, to increase the appeal, especially to people who already own the original release, it is common to include remixes and/or alternate takes of popular songs; even new material (previously unreleased). At times a greatest hits compilation is the original release for songs that have themselves been released as a single and charted successfully.

Notable compilations

Madonna's The Immaculate Collection is the best selling greatest hits compilation by a solo artist; all of the songs on it are presented in different versions than the original hit versions. The Eagles' Their Greatest Hits (1971–1975) is the best selling greatest hits compilation by a group and also one of the ten best selling albums in history. Greatest hits albums are typically produced after an artist has had enough successful songs to fill out an album release. Some artists, such as Mariah Carey, Madonna, Janet Jackson, Britney Spears, Elvis Presley, Michael Jackson, The Beatles, Kenny Rogers, Aerosmith, Kiss, U2, Dolly Parton, Journey, Los Tigres del Norte, Queen, Kylie Minogue and Billy Joel, have released multiple greatest hits albums through their long careers. Some greatest hits albums are released only at the end of the artist or group's career. For example, My Chemical Romance released a greatest hits album after they disbanded. Other artists, like Eminem have released hits albums in the center of their success. He released Curtain Call: The Hits in 2005 and then Shady XV as a compilation album in 2014.