Vertebral column

The vertebral column is a bony structure found in Vertebrates. It is formed from the vertebrae.

In humans[link]

Human vertebral column.

In human anatomy, the vertebral column usually consists of 24 articulating vertebrae,^[1] and 9 fused vertebrae in the sacrum and the coccyx. It is situated in the dorsal aspect of the torso, separated by intervertebral discs. It houses and protects the spinal cord in its spinal canal.

There are normally thirty-three (33) vertebrae in humans, including the five that are fused to form the sacrum (the others are separated by intervertebral discs) and the four coccygeal bones that form the tailbone.

The upper three regions comprise the remaining 24, and are grouped under the names cervical (7 vertebrae), thoracic (12 vertebrae) and lumbar (5 vertebrae), according to the regions they occupy. This number is sometimes increased by an additional vertebra in one region, or it may be diminished in one region, the deficiency often being supplied by an additional vertebra in another. The number of cervical vertebrae is, however, very rarely increased or diminished.^{[citation needed]}

In other animals[link]

In all animals, vertebrae are defined by the regions of the vertebral column they occur in. Cervical vertebrae are those in the neck area. With exception of two sloth genera (Choleopus and Bradypus) and the manatee (Trichechus), all mammals have seven cervical vertebrae.^[2] In other vertebrates it can range from a single vertebra in amphibians, to as many as 25 in swans or 76 in the extinct plesiosaur Elasmosaurus. The dorsal vertebrae range from the bottom of the neck to the top of the pelvis. Dorsal vertebrae attached to ribs are called thoracic vertebrae, while those without ribs are called lumbar vertebrae. The sacral vertebrae are those in the pelvic region, and range from one in amphibians, to two in most birds and modern reptiles, or up to 3 to 5 in mammals. When multiple sacral vertebrae are fused into a single structure, it is called the sacrum. The synsacrum is a similar fused structure found in birds that is composed of the sacral, lumbar, and some of the thoracic and caudal vertebra, as well as the pelvic girdle. Caudal vertebrae compose the tail, and the final few can be fused into the pygostyle in birds, or into the coccygeal or tail bone in chimpanzees (and humans).

Structure of individual vertebrae[link]

Individual vertebrae are composed of a centrum (body), arches protruding from the top and bottom of the centrum, and various processes projecting from the centrum and/or arches. An arch extending from the top of the centrum is called a neural arch, while the hemal arch or chevron is found underneath the centrum in the caudal (tail) vertebrae of fish, most reptiles, some birds, and some mammals with long tails. The vertebral processes can either give the structure rigidity, help them articulate with ribs, or serve as muscle attachment points. Common types are transverse process, diapophyses, parapophyses, and zygapophyses (both the cranial zygapophyses and the caudal zygapophyses).

Classification[link]

The centra of the vertebra can be classified based upon the fusion of its elements. In aspidospondyly, bones such as the neural spine, the pleurocentrum and the intercentrum are separate ossifications. Fused elements, however, classify a vertebra as having holospondyly.

A vertebra can also be described in terms of the shape of the ends of the centra. Centra with flat ends are acoelous, like those in mammals. These flat ends of the centra are especially good at supporting and distributing compressive forces. Amphicoelous vertebra have centra with both ends concave. This shape is common in fish, where most motion is limited. Amphicoelous centra often are integrated with a full notochord. Procoelous vertebrae are anteriorly concave and posteriorly convex. They are found in frogs and modern reptiles. Opisthocoelous vertebrae are the opposite, possessing anterior convexity and posterior concavity. They are found in salamanders. Heterocoelous vertebrae have saddle-shaped articular surfaces. This type of configuration is seen in turtles that retract their necks, and birds, because it permits extensive lateral and vertical flexion motion without stretching the nerve cord too extensively or wringing it about its long axis.

Fish and amphibians[link]

The vertebrae of lobe-finned fishes consist of three discrete bony elements. The vertebral arch surrounds the spinal cord, and is of broadly similar form to that found in most other vertebrates. Just beneath the arch lies a small plate-like pleurocentrum, which protects the upper surface of the notochord, and below that, a larger arch-shaped intercentrum to protect the lower border. Both of these structures are embedded within a single cylindrical mass of cartilage. A similar arrangement was found in the primitive Labyrinthodonts, but in the evolutionary line that led to reptiles (and hence, also to mammals and birds), the intercentrum became partially or wholly replaced by an enlarged pleurocentrum, which in turn became the bony vertebral body.^[3]

In most ray-finned fishes, including all teleosts, these two structures are fused with, and embedded within, a solid piece of bone superficially resembling the vertebral body of mammals. In living amphibians, there is simply a cylindrical piece of bone below the vertebral arch, with no trace of the separate elements present in the early tetrapods.^[3]

In cartilagenous fish, such as sharks, the vertebrae consist of two cartilagenous tubes. The upper tube is formed from the vertebral arches, but also includes additional cartilagenous structures filling in the gaps between the vertebrae, and so enclosing the spinal cord in an essentially continuous sheath. The lower tube surrounds the notochord, and has a complex structure, often including multiple layers of calcification.^[3]

Lampreys have vertebral arches, but nothing resembling the vertebral bodies found in all higher vertebrates. Even the arches are discontinuous, consisting of separate pieces of arch-shaped cartilage around the spinal cord in most parts of the body, changing to long strips of cartilage above and below in the tail region. Hagfishes lack a true vertebral column, and are therefore not properly considered vertebrates, but a few tiny neural arches are present in the tail.^[3]

Amniotes[link]

The general structure of human vertebrae is fairly typical of that found in mammals, reptiles, and birds. The shape of the vertebral body does, however, vary somewhat between different groups. In mammals, such as humans, it typically has flat upper and lower surfaces, while in reptiles the anterior surface commonly has a concave socket into which the expanded convex face of the next vertebral body fits. Even these patterns are only generalisations, however, and there may be variation in form of the vertebrae along the length of the spine even within a single species. Some unusual variations include the saddle-shaped sockets between the cervical vertebrae of birds and the presence of a narrow hollow canal running down the centre of the vertebral bodies of geckos and tuataras, containing a remnant of the notochord.^[3]

Reptiles often retain the primitive intercentra, which are present as small crescent-shaped bony elements lying between the bodies of adjacent vertebrae; similar structures are often found in the caudal vertebrae of mammals. In the tail, these are attached to chevron-shaped bones called haemal arches, which attach below the base of the spine, and help to support the musculature. These latter bones are probably homologous with the ventral ribs of fish. The number of vertebrae in the spines of reptiles is highly variable, and may be several hundred in some species of snake.^[3]

In birds, there is a variable number of cervical vertebrae, which often form the only truly flexible part of the spine. The thoracic vertebrae are partially fused, providing a solid brace for the wings during flight. The sacral vertebrae are fused with the lumbar vertebrae, and some thoracic and caudal vertebrae, to form a single structure, the synsacrum, which is thus of greater relative length than the sacrum of mammals. In living birds, the remaining caudal vertebrae are fused into a further bone, the pygostyle, for attachment of the tail feathers.^[3]

Aside from the tail, the number of vertebrae in mammals is generally fairly constant. There are almost always seven cervical vertebrae (sloths and manatees are among the few exceptions), followed by around twenty or so further vertebrae, divided between the thoracic and lumbar forms, depending on the number of ribs. There are generally three to five vertebrae with the sacrum, and anything up to fifty caudal vertebrae.^[3]

References[link]

Zoë Bell
Bell at a Grindhouse premiere in Austin, Texas
Born	Zoë E. Bell (1978-11-17) 17 November 1978 (age 33) Waiheke Island, New Zealand
Occupation	Actress Stuntwoman
Years active	1992–present

Zoë E. Bell (born 17 November 1978) is a stuntwoman and actress from New Zealand. Some of her most notable stunt work includes doubling for Lucy Lawless on Xena: Warrior Princess and for Uma Thurman in Kill Bill. As an actress, she has appeared both on television and in feature films and also starred in the web series Angel of Death. She is probably most recognized for playing herself in the Quentin Tarantino film, Death Proof.

Early life[link]

Bell was born in New Zealand to Tish, a nurse, and Andrew Bell, a doctor.^[1] She has a younger brother named Jake.^[2] She grew up on Waiheke Island in Auckland. At a young age, she participated in competitive gymnastics and at the age of 15, she began studying Taekwon-Do. She also participated in dance, high diving, scuba, and track and field activities. Bell attended Auckland Girls' Grammar School and Selwyn College.

Career[link]

Bell began her career in 1992 when her father treated a stuntman for a head injury and came home with a phone number for her to call. Her first stunt job was jumping out of a car in Shortland Street, a New Zealand soap opera.

She did stunts for Hercules: The Legendary Journeys and Xena: Warrior Princess, both of which were filmed in New Zealand; by the fourth season of Xena, she was the stunt double for Lucy Lawless. She fractured vertebrae in her back doing wire work on the show, but continued working for a week until another stunt, in which a breakaway chair was smashed on her back, incapacitated her.

After Xena, she did a number of small films and TV stunt work, including stunt coordinating and playing a small role in a short film Reflections with Adrienne Wilkinson (with whom she had previously worked on Xena). She then went on to double for Uma Thurman in Quentin Tarantino's Kill Bill.

Though she was initially hired as Thurman's "crash and smash" double,^[3] the stunt team realized Bell would also make an ideal double for fight scenes and she was trained accordingly. Bell had to learn to fight in the wushu style.^[4] Near the end of filming for Kill Bill: Volume 2, she injured her ribs and the ligaments in her wrist while simulating being thrown backwards by a shotgun blast. Bell required surgery and spent several months recuperating.^[5] After production wrapped on Kill Bill, she received "The Bells" sign which hung outside the home of the Vernita Green character. She later gave it to her parents.

Tarantino was so impressed with her that he cast her in a leading role in his next film, Death Proof, in which she played herself and performed her own stunts, the most notable of which occurs when she hangs onto the hood of a speeding 1970 Dodge Challenger.^[6] After Death Proof, she did stunt work for the movie Catwoman, in which she performed high falls and acted as a double for Sharon Stone.

In 2004, the documentary Double Dare was released. It focused primarily on Bell and veteran stuntwoman Jeannie Epper, following them during their travails in Hollywood. The film presented a view of opposing ends of the stuntwoman spectrum, with the aging Epper continuing her search for work in an industry where age is not necessarily considered an asset and Bell, then a Hollywood newcomer, trying to break into the industry. The filming of Double Dare covered Zoë's career from the end of Xena to the beginning of her work on Kill Bill: Volume 1.

In 2004, Bell and Angela Meryl (Vivica A. Fox's stunt double) were nominated at the Taurus World Stunt Awards in the categories "Best Overall Stunt by a Woman" and "Best Fight" for their doubling of the knife fight between the characters Beatrix Kiddo and Vernita Green in Kill Bill: Volume 1.^[7] In 2005, Bell was nominated for a Taurus in the categories "Best Overall Stunt by a Woman," "Best Fight," and "Best High Work." She and Monica Staggs (Daryl Hannah's double) won Best Overall Stunt and Best Fight for their fight in Budd's trailer in Kill Bill 2. Her Best High Work nomination was for a fall of over 200 feet in the film Catwoman.

In August 2007, Bell confirmed she had signed on to play the lead role in a film about an American soldier who, upon returning to the US from a tour of duty in Iraq, helps a young girl in trouble.^[8] She told the New Zealand Herald she would do her own stunts in the as-yet untitled film, and that the American accent was "a big challenge". In October 2007, Variety reported that Bell would appear in the 2009 film Game, starring Gerard Butler; the movie was later renamed Gamer.^[9]

Bell was a guest star in the fourth season of Lost, playing the role of the freighter team's radio contact, Regina. She stated in interviews that the role required a little acting and some stunt work. She appeared on screen only in episode 7 of season 4, entitled "Ji Yeon."

In 2008, Bell starred alongside her former Xena colleague Lucy Lawless in Sony (Crackle)'s web series Angel of Death which debuted online in early 2009.^[10]

Bell also played a medical technician who moonlights as "Bloody Holly", a roller derby star, in Drew Barrymore's 2009 directorial debut, Whip It.^[11]

She appeared alongside Wesley Snipes in Italian director Giorgio Serafini's 2010 thriller, Game of Death.^[12] She can also be seen in the music video of Noel Gallagher’s High Flying Birds' 2012 single 'Dream On'.

Filmography[link]

Bell at the 2007 Scream Awards

• Shortland Street (1992–2005)
• Xena: Warrior Princess (1995) TV Series (stunt double) (unknown episodes)
• Hercules: The Legendary Journeys – (1995–1999 TV series) stunt work
• The Chosen (1998) stunt work
• Young Hercules (1998 TV)
• Jacksons Wharf (1999 TV)
• Amazon High (1999 TV) – background action stunt work
• Cleopatra 2525 Female betrayer (1 episode, 2000)
• Jack of All Trades (2000 TV)
• The Bunker Murders (2002 TV)
• Riverworld (2003 teleplay) stunt work
• The Extreme Team (2003) (stunt double) aka The X-Team (USA: TV title)
• Kill Bill: Vol. 1 (2003) (stunt double)
• Kill Bill: Vol. 2 (2004) (stunt double)
• Double Dare (2004)
• Catwoman (2004) (stunt double)
• Ultraviolet (2004)
• Alias (stunt double) (1 episode, 2005)
• Penny Dreadful (2006) (stunt double)
• The Devil's Den (2006) (stunt double)
• Poseidon (2006) (stunts)
• The Kingdom (2007) (stunts)
• Planet Terror (2007) (stunts)
• Death Proof (2007) (as herself)
• Reflections (2008) (Woman in Mirror, stunt coordinator)
• Lost (2008) (Regina) (Season 4)
• The Final Destination (2009) (stunt double)
• Inglourious Basterds (2009) (stunt double)
• Angel of Death (2009)
• Whip It (2009) (Bloody Holly)
• The Chronicles of Nerm (2009) (voice)
• The Collector (2009) (Stunt Double)
• Gamer (2009) (Sandra)
• Fallout: New Vegas (2010) (Melissa & Diane & Linda Schuler & Alice Hoestler)(video game voice-over)
• Game of Death (2010) (Floria)
• Gossip Girl (2011) (1 episode)
• Hansel and Gretel: Witch Hunters (2013)

Awards and nominations[link]

References[link]

External links[link]

Wikimedia Commons has media related to: Zoë Bell

• Zoe Bell at the Internet Movie Database
• Zoë Bell Producer Profile for The 1 Second Film