Neck

The neck is the part of the body, on many terrestrial or secondarily aquatic vertebrates, that distinguishes the head from the torso or trunk. The adjective (from Latin) signifying "of the neck" is cervical (though in non-technical contexts, this is more frequently used to describe the cervix).

Structure

The cervical spine

The cervical portion of the human spine comprises seven bony segments, typically referred to as C-1 to C-7, with cartilaginous discs between each vertebral body. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In addition, the neck is highly flexible and allows the head to turn and flex in all directions. From top to bottom the cervical spine is gently curved in convex-forward fashion. It is the least marked of all the curves of the column.

Soft tissue anatomy

In the middle line below the chin can be felt the body of the hyoid bone, just below which is the prominence of the thyroid cartilage called "Adam's apple", better marked in men than in women. Still lower the cricoid cartilage is easily felt, while between this and the suprasternal notch the trachea and isthmus of the thyroid gland may be made out. At the side the outline of the sternomastoid muscle is the most striking mark; it divides the anterior triangle of the neck from the posterior. The upper part of the former contains the submaxillary gland also known as the submandibular glands, which lies just below the posterior half of the body of the jaw. The line of the common and the external carotid arteries may be marked by joining the sterno-clavicular articulation to the angle of the jaw.

Neck (Chinese constellation)

The Neck mansion (亢宿, pinyin: Kàng Xiù) is one of the Twenty-eight mansions of the Chinese constellations. It is one of the eastern mansions of the Azure Dragon.

In Chinese Cosmology, the Kang Constellation is associated with the Kidney Organ. 亢 is a picture of a person standing with their legs open, as in horse stance, and so holds the quality of strength that comes through a proper foundation. This matches up with Chapter 8 of the Suwen, which says that the Kidney is in charge of strength and fortification. The Kidney houses the Zhi, which is in charge of solid grounding in one’s life purpose. Kang is also the neck or throat of the Azure Dragon of the East, which, while the throat area is ruled by the Lung, has everything to do with sound—pointing to the Kidney’s orifice of the ears. Around the 5th Century BC, it is believed that eclipses would take place in this constellation. This coming together of the Sun and the moon works as a symbol that points towards the ShaoYin relationship of the Kidney and Heart.

Neck (music)

The neck is the part of certain string instruments that projects from the main body and is the base of the fingerboard, where the fingers are placed to stop the strings at different pitches. Guitars, banjos, ukuleles, lutes, the violin family, and the mandolin family are examples of instruments which have necks. Necks are also an integral part of certain woodwind instruments, like for instance the saxophone.

The word for neck also sometimes appears in other languages in musical instructions. The French term in this case is manche.

Guitar

The neck of a guitar includes the guitar's frets, fretboard, tuners, headstock, and truss rod. The wood used to make the fretboard will usually differ from the wood in the rest of the neck. The bending stress on the neck is considerable, particularly when heavier gauge strings are used (see Strings and tuning), and the ability of the neck to resist bending (see Truss rod) is important to the guitar's ability to hold a constant pitch during tuning or when strings are fretted. The rigidity of the neck with respect to the body of the guitar is one determinant of an instrument's quality. Conversely, the ability to change the pitch of the note slightly by deliberately bending the neck forcibly with the fretting arm is a technique occasionally used, particularly in the blues genre and those derived from it, such as rock and roll. The shape of the neck's cross-section can also vary from a gentle curve to a more pronounced "V" shape. (The fretboard is typically gently rounded across its width.)

Sod (disambiguation)

Sod is grass and the part of the soil beneath it held together by the roots.

Sod may also refer to:

SOD or S.O.D. may refer to:

Science

Entertainment

Other uses

See also

SOD1

Superoxide dismutase [Cu-Zn] also known as superoxide dismutase 1 or SOD1 is an enzyme that in humans is encoded by the SOD1 gene, located on chromosome 21. SOD1 is one of three human superoxide dismutases. It is implicated in apoptosis and amyotrophic lateral sclerosis.

Structure

SOD1 is a 32 kDa homodimer which forms a β-barrel and contains an intramolecular disulfide bond and a binuclear Cu/Zn site in each subunit. This Cu/Zn site holds the copper and a zinc ion and is responsible for catalyzing the disproportionation of superoxide to hydrogen peroxide and dioxygen. The maturation process of this protein is complex and not fully understood, involving the selective binding of copper and zinc ions, formation of the intra-subunit disulfide bond between Cys-57 and Cys-146, and dimerization of the two subunits. The copper chaperone for Sod1 (CCS) facilitates copper insertion and disulfide oxidation. Though SOD1 is synthesized in the cytosol can mature there, the fraction of expressed, and still immature, SOD1 targeted to the mitochondria must be inserted into the intermembrane space. There, it forms the disulfide bond, though not metallation, required for its maturation. The mature protein is highly stable, but unstable when in its metal-free and disulfide-reduced forms. This manifests in vitro, as the loss of metal ions results in increased SOD1 aggregation, and in disease models, where low metallation is observed for insoluble SOD1. Moreover, the surface-exposed reduced cysteines could participate in disulfide crosslinking and, thus, aggregation.

SOD2

Superoxide dismutase 2, mitochondrial (SOD2), also known as manganese-dependent superoxide dismutase (MnSOD), is an enzyme which in humans is encoded by the SOD2 gene on chromosome 6.

Structure

The SOD2 gene contains five exons interrupted by four introns, an uncharacteristic 5′-proximal promoter that possesses a GC-rich region in place of the TATA or CAAT, and an enhancer in the second intron. The proximal promoter region contains multiple binding sites for transcription factors, including specific-1 (Sp1), activator protein 2 (AP-2), and early growth response 1 (Egr-1). This gene is a the mitochondrial member of the iron/manganese superoxide dismutase family. It encodes a mitochondrial matrix protein that forms a homotetramer and binds one manganese ion per subunit. The manganese site forms a trigonal bipyramidal geometry with four ligands from the protein and a fifth solvent ligand. This solvent ligand is a hydroxide believed to serve as the electron acceptor of the enzyme. The active site cavity consists of a network of side chains of several residues associated by hydrogen bonding, extending from the aqueous ligand of the metal. Of note, the highly conserved residue Tyr34 plays a key role in the hydrogen-bonding network, as nitration of this residue inhibits the protein's catalytic ability. This protein also possesses an N-terminal mitochondrial leader sequence which targets it to the mitochondrial matrix, where it converts mitochondrial-generated reactive oxygen species from the respiratory chain to H2.Alternate transcriptional splice variants, encoding different isoforms, have been characterized.