WordNet

form vertical ribs by knitting; "A ribbed sweater"
a projecting molding on the underside of a vault or ceiling; may be ornamental or structural
support resembling the rib of an animal
any of the 12 pairs of curved arches of bone extending from the spine to or toward the sternum in humans (and similar bones in most vertebrates) (同)costa
a riblike supporting or strengthening part of an animal or plant
a teasing remark
cut of meat including one or more ribs
relating to or associated with the neck
of or relating to the cervix of the uterus; "cervical cancer"
a pattern of symptoms indicative of some disease
a complex of concurrent things; "every word has a syndrome of meanings"

PrepTutorEJDIC

『肋骨』(ろっこつ),あばら骨 / (骨付きの)あばら肉 / 肋骨状の物;(船の)肋骨,肋材(ろくざい);(丸天井の)萩減(ろく)(建物・橋の)横ばり;(かさなどの) 骨 / 葉脈(vein) / (編物・織物の)うね / …‘に'肋骨(肋材)をつける / 〈編物〉‘に'うね模様をつける / 《話》…‘を'いじめる,からかう
(子宮などの)頚(けい)部の(にできた)
(疾患の徴候となる一群の)症徴候,症候群 / (事件・社会的状態などのパターンを示す)徴候形態
roentgen / recto

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/10/31 19:51:11」(JST)

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3D CT reconstruction of a cervical rib.

A cervical rib in humans is a supernumerary (or extra) rib which arises from the seventh cervical vertebra. Sometimes known as "neck ribs",^[1] their presence is a congenital abnormality located above the normal first rib. A cervical rib is estimated to occur in 0.6% (1 in 150 people)^[2] to 0.8%^[3] of the population. Individuals may have a cervical rib on the right, left or both sides.^[4]

Most cases of cervical ribs are not clinically relevant and do not have symptoms; cervical ribs are generally discovered incidentally.^[4]^[3] However, they vary widely in size and shape,^[3] and in rare cases, they may cause problems such as contributing to thoracic outlet syndrome, because of pressure on the nerves that may be caused by the presence of the rib.^[5]

A cervical rib represents a persistent ossification of the C7 lateral costal element. During early development, this ossified costal element typically becomes re-absorbed. Failure of this process results in a variably elongated transverse process or complete rib that can be anteriorly fused with the T1 first rib below.^[6]

Associated conditions

The presence of a cervical rib can cause a form of thoracic outlet syndrome due to compression of the lower trunk of the brachial plexus or subclavian artery. These structures become encroached upon by the cervical rib and scalene muscles.

Compression of the brachial plexus may be identified by weakness of the muscles around the muscles in the hand, near the base of the thumb. Compression of the subclavian artery is often diagnosed by finding a positive Adson's sign on examination, where the radial pulse in the arm is lost during abduction and external rotation of the shoulder. A positive Adson's sign is non-specific for the presence of a cervical rib however, as many individuals without a cervical rib will have a positive test.

Other animals

Many vertebrates, especially reptiles, have cervical ribs as a normal part of their anatomy rather than a pathological condition. Some sauropods had exceptionally long cervical ribs; those of Mamenchisaurus hochuanensis were nearly 4 meters long.

In birds, the cervical ribs are small and completely fused to the vertebrae.

In mammals the ventral parts of the transverse processes of the cervical vertebrae are the fused-on cervical ribs.

Recent studies have also found a high percent of cervical ribs in woolly mammoths. It is believed that the decline in mammoth numbers may have forced inbreeding within the species which in turn has increased the number of mammoths being born with cervical ribs. Cervical ribs have been connected with leukaemia in children (humans), so it has given scientists new evidence to believe that the mammoth's extinction was attributed to the condition.^[7]

Anatomy diagrams

Detailed diagrams of a cervical rib

References

^ Selim, Jocelyn. "Useless Body Parts".
^ Galis F (1999). "Why do almost all mammals have seven cervical vertebrae? Developmental constraints, Hox genes, and cancer". J. Exp. Zool. 285 (1): 19–26. doi:10.1002/(SICI)1097-010X(19990415)285:1<19::AID-JEZ3>3.0.CO;2-Z. PMID 10327647.
^ ^a ^b ^c Terry Yochum; Lindsay Rowe (2005). Essentials of Skeletal Radiology (3 ed.). Lippencott & Williams.
^ ^a ^b Walden, Michael; et al. (2013). "Cervical ribs: identification on MRI and clinical relevance". Clinical Imaging 37 (5): 938–941.
^ Guttentag, Adam; Salwen, Julia (1999). "Keep Your Eyes on the Ribs: The Spectrum of Normal Variants and Diseases That Involve the Ribs". RadioGraphics 19 (5). doi:10.1148/radiographics.19.5.g99se011125.
^ E. McNally, B. Sandin & R. A. Wilkins (June 1990). "The ossification of the costal element of the seventh cervical vertebra with particular reference to cervical ribs". Journal of anatomy 170: 125–129. PMC 1257068. PMID 2123844.
^ http://www.iflscience.com/plants-and-animals/woolly-mammoths-suffered-major-birth-defects-extinction

UpToDate Contents

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1. 胸郭出口症候群の概要 overview of thoracic outlet syndromes
2. 原発性（特発性）上肢深部静脈血栓症 primary spontaneous upper extremity deep vein thrombosis
3. 腕神経叢症候群 brachial plexus syndromes
4. 投擲による上肢の傷害：臨床症状および診断的アプローチ throwing injuries of the upper extremity clinical presentation and diagnostic approach
5. 肺尖部胸壁浸潤肺癌（パンコースト腫瘍） superior pulmonary sulcus pancoast tumors

English Journal

Lung herniation after supraclavicular thoracic outlet decompression.

Su F, Zoole JB, Thompson RW, Meyers BF, Kuo E.SourceDivision of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri.
The Annals of thoracic surgery.Ann Thorac Surg.2012 May;93(5):1720-2.
Lung herniation after first rib resection for thoracic outlet syndrome (TOS) has not been reported to our knowledge. We present a unique case of cervical lung herniation causing displacement of the brachial plexus and chronic pain in a patient who had previously undergone supraclavicular thoracic ou
PMID 22541209

Japanese Journal

頚肋切除術が有効であった頚肋症候群の1例

原田淳,西嶌美知春,西村真実,栗本昌紀,遠藤俊郎
脳神経外科ジャーナル 18(8), 614-618, 2009-08-20
頚肋は胸郭出口症候群の原因となりうる先天奇形として古くから報告されている.しかし,実際の臨床の場面で遭遇する機会はまれである.今回われわれは,上肢の疼痛,しびれ,脱力を主訴とし,頚肋を有する20歳の男性症例を経験した.理学所見および補助検査の結果,頚肋症候群と診断した.保存的治療が奏効しなかったため,頚肋切除術を行い良好な成績を得たので,頚肋症候群の外科的治療について若干の文献的考察を含めて報告す …
NAID 110007340617

冠動脈バイパス術後にHorner症候群を呈した1例

村上達哉,加藤裕貴,牧野裕
日本心臓血管外科学会雑誌 36(5), 273-276, 2007-09-15
胸骨正中切開による開心術後にHorner症候群を発症することはまれであり,本邦での報告例はほとんどない.症例は77歳,女性.頻回な労作時胸痛を訴え精査したところ,陳旧性下壁梗塞,重症3枝病変,虚血性僧帽弁閉鎖不全症と診断された.手術は仰臥位,左上肢80度水平外転位で開始した.胸骨正中切開後,Delacroix-Chevalier開胸器を用いて約14cm開胸し,胸骨左縁を挙上して左内胸動脈を採取した …
NAID 110006419167