arm

(ärm)

1. An upper limb of the human body, connecting the hand and wrist to the shoulder.
2. A part similar to a human arm, such as the forelimb of an animal or a long part projecting from a central support in a machine.
3. Something, such as a sleeve on a garment or a support on a chair, that is designed to cover or support the human arm.
4. A relatively narrow extension jutting out from a large mass: an arm of the sea. See synonyms at branch.
5. An administrative or functional branch, as of an organization.
6. Power or authority: the long arm of the law.
7. Sports. The skill of throwing or pitching a ball well.

an arm and a leg Slang.

1. An excessively high price: a cruise that cost an arm and a leg.

1. With arms linked together: They walked across the beach arm in arm.

1. At such a distance that physical or social contact is discouraged: kept the newcomer at arm's length at first.

1. With great cordiality and hospitality.

[Middle English, from Old English earm.]

(ärm)

1. A weapon, especially a firearm: troops bearing arms; ICBMs, bombs, and other nuclear arms.
2. A branch of a military force: infantry, armor, and other combat arms.
3. arms
   1. Warfare: a call to arms against the invaders.
   2. Military service: several million volunteers under arms; the profession of arms.
4. arms
   1. Heraldry. Bearings.
   2. Insignia, as of a state, an official, a family, or an organization.

1. To supply or equip oneself with weaponry.
2. To prepare oneself for warfare or conflict.

1. To equip with weapons: armed themselves with loaded pistols; arm a missile with a warhead; arm a nation for war.
2. To equip with what is needed for effective action: tax advisers who were armed with the latest forms.
3. To provide with something that strengthens or protects: a space reentry vehicle that was armed with a ceramic shield.
4. To prepare (a weapon) for use or operation, as by releasing a safety device.

up in arms

1. Extremely upset; indignant.

[From Middle English armes, weapons, from Old French, pl. of arme, weapon, from Latin arma, weapons. V., Middle English armen, from Old French armer, from Latin armāre, from arma.]

View more Health videos

For more information on arm, visit Britannica.com.

noun

1. Something resembling or structurally analogous to a tree branch: branch, fork, offshoot. See part/whole.
2. A part added to a main structure: annex, extension, wing. See part/whole.
3. A component of government that performs a given function: agency, branch, department, division, organ, wing. See part/whole.

Idioms beginning with arm:
arm in arm

See also at arm's length; babe in arms; forewarned is forearmed; give one's eyeteeth (right arm); long arm of the law; one-armed bandit; put the arm on; shot in the arm; take up arms; talk someone's arm off; twist someone's arm; up in arms; with one arm tied behind; with open arms.

Definition: subdivision, annex
Antonyms: body, division, main

v

Definition: equip with weapon or power
Antonyms: disarm

v. 1. supply or provide with weapons: both sides armed themselves with grenades and machine guns.

2. activate the fuse of (a bomb, alarm, or other device) so that it is ready to explode: the bomb would be quite safe until it was armed.

See the Introduction, Abbreviations and Pronunciation for further details.

Region of the body extending the length of the humerus.

Arms are the functional and creative extensions of the body, allowing one to hold and embrace one's desires. If the arms are obstructed in any way, a loss of one's power and ability may be indicated.

1. the limb segment between the shoulder and elbow joints; sometimes called the upper arm as distinct from the lower arm which is the section from elbow to carpus.
2. loosely, the free part of the thoracic limb, especially of bipeds.

An extension or projection of a removable partial denture framework.

• Limbs and Extremities - arm: upper limb between shoulder and wrist
• Coastal Land, Islands, and the Sea - arm: narrow inland extension of sea
• Building and Machine Parts - arm: small extension attached horizontally at angle to large base
• Garment Parts - arm: tube of material from shoulder to wrist

This article is about the upper part of the human upper limb. For other uses, see Arm (disambiguation).

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (June 2011)

Arm
The human arm
Cross-section through the middle of upper arm.
Latin	bracchium GraySubject =

In human anatomy, the arm is the part of the upper limb between the shoulder and the elbow joints. In other animals, the term arm can also be used for analogous structures, such as one of the paired forelimbs of a four-legged animal or the arms of cephalopods. In anatomical usage, the term arm refers specifically to the segment between the shoulder and the elbow,^[1][2] while the segment between the elbow and wrist is the forearm. However, in common, literary, and historical usage, arm refers to the entire upper limb from shoulder to wrist. This article uses the former definition; see upper limb for the wider definition.

In primates the arm is adapted for precise positioning of the hand and thus assist in the hand's manipulative tasks. The ball and socket shoulder joint allows for movement of the arms in a wide circular plane, while the structure of the two forearm bones which can rotate around each other allows for additional range of motion at that level.

Contents 1 Skeleton 2 Muscles 3 Nerve and blood supply 3.1 Innervation 3.2 Arteries 3.3 Veins 4 Additional images 5 See also 6 References

Skeleton

Bone structure of a human arm.

The humerus is the bone of the arm. It joins with the scapula above in the shoulder at the glenohumeral joint and with the ulna and radius below at the elbow. The elbow joint is the hinge joint between the distal end of the humerus and the proximal ends of the radius and ulna. The humerus cannot be broken easily. Its strength allows it to handle loading up to 300 pounds (140 kg).

Muscles

The arm is divided by a fascial layer (known as lateral and medial intermuscular septa) separating the muscles into two osteofascial compartments: the anterior and the posterior compartments of the arm. The fascia merges with the periosteum (outer bone layer) of the humerus. The compartments contain muscles which are innervated by the same nerve and perform the same action.

Two other muscles are considered to be partially in the arm:

• The large deltoid muscle is considered to have part of its body in the anterior compartment. This muscle is the main abductor muscle of the upper limb and extends over the shoulder.
• The brachioradialis muscle originates in the arm but inserts into the forearm. This muscle is responsible for rotating the hand so its palm faces forward (supination).

Nerve and blood supply

The cubital fossa (colloquially known as the elbow pit) is clinically important for venepuncture and for blood pressure measurement.

Innervation

Cutaneous innervation of the right upper extremity.

The musculocutaneous nerve, from C5, C6, C7, is the main supplier of muscles of the anterior compartment. It originates from the lateral cord of the brachial plexus of nerves. It pierces the coracobrachialis muscle and gives off branches to the muscle, as well as to brachialis and biceps brachii. It terminates as the anterior cutaneous nerve of the forearm.

The radial nerve, which is from the fifth cervical spinal nerve to the first thoracic spinal nerve, originates as the continuation of the posterior cord of the brachial plexus. This nerve enters the lower triangular space (an imaginary space bounded by, amongst others, the shaft of the humerus and the triceps brachii) of the arm and lies deep to the triceps brachii. Here it travels with a deep artery of the arm (the profunda brachii), which sits in the radial groove of the humerus. This fact is very important clinically as a fracture of the bone at the shaft of the bone here can cause lesions or even transections in the nerve.

Other nerves passing through give no supply to the arm. These include:

• The median nerve, nerve origin C5-T1, which is a branch of the lateral and medial cords of the brachial plexus. This nerve continues in the arm, travelling in a plane between the biceps and triceps muscles. At the cubital fossa, this nerve is deep to the pronator teres muscle and is the most medial structure in the fossa. The nerve passes into the forearm.
• The ulnar nerve, origin C8-T1, is a continuation of the medial cord of the brachial plexus. This nerve passes in the same plane as the median nerve, between the biceps and triceps muscles. At the elbow, this nerve travels posterior to the medial epicondyle of the humerus. This means that condylar fractures can cause lesion to this nerve.

Arteries

Main arteries of the arm.

The main artery in the arm is the brachial artery. This artery is a continuation of the axillary artery. The point at which the axillary becomes the brachial is distal to the lower border of teres major. The brachial artery gives off an important branch, the profunda brachii (deep artery of the arm). This branching occurs just below the lower border of teres major.

The brachial artery continues to the cubital fossa in the anterior compartment of the arm. It travels in a plane between the biceps and triceps muscles, the same as the median nerve and basilic vein. It is accompanied by venae comitantes (accompanying veins). It gives branches to the muscles of the anterior compartment. The artery is in between the median nerve and the tendon of the biceps muscle in the cubital fossa. It then continues into the forearm.

The profunda brachii travels through the lower triangular space with the radial nerve. From here onwards it has an intimate relationship with the radial nerve. They are both found deep to the triceps muscle and are located on the spiral groove of the humerus. Therefore fracture of the bone may not only lead to lesion of the radial nerve, but also haematoma of the internal structures of the arm. The artery then continues on to anastamose with the recurrent radial branch of the brachial artery, providing a diffuse blood supply for the elbow joint.

Veins

The veins of the arm carry blood from the extremities of the limb, as well as drain the arm itself. The two main veins are the basilic and the cephalic veins. There is a connecting vein between the two, the median cubital vein, which passes through the cubital fossa and is clinically important for venepuncture (withdrawing blood).

The basilic vein travels on the medial side of the arm and terminates at the level of the seventh rib.

The cephalic vein travels on the lateral side of the arm and terminates as the axillary vein. It passes through the deltopectoral triangle, a space between the deltoid and the pectoralis major muscles.

Additional images

See also

• Anatomical terms of location
• Anthropometry of the upper arm
• Humerus fracture

References

Wikimedia Commons has media related to: Arm

Look up arm in Wiktionary, the free dictionary.

1. ^ "arm" at Dorland's Medical Dictionary^{[dead link]}
2. ^ MeSH Arm

v d e Human regional anatomy (TA A01.1) Head Forehead · Ear · Jaw · Face (Cheek, Eye, Nose, Mouth, Chin) · Occiput · Scalp · Temple Neck Throat · Adam's apple Trunk Chest (Breast) · Abdomen (Navel) · Back · Pelvis (Sex organs) Limbs Upper limb Shoulder · Axilla · Arm Elbow · Forearm Wrist · Hand · Finger (Thumb · Index · Middle · Ring · Little) Lower limb/ (see also leg) Hip · Buttocks · Thigh Knee · Calf · Crus Ankle · Heel · Foot · Toe (Hallux · Long  • Third  • Fourth  • Fifth) · Sole General anatomy: systems and organs, regional anatomy, planes and lines, superficial axial anatomy, superficial anatomy of limbs

v d e List of muscles of upper limbs (TA A04.6, GA 4.432) Shoulder deltoid · rotator cuff (supraspinatus, infraspinatus, teres minor, subscapularis) · teres major fascia: Deltoid fascia · Supraspinous fascia · Infraspinous fascia Arm (compartments) Anterior coracobrachialis · biceps brachii · brachialis Posterior triceps brachii · anconeus · Articularis cubiti Fascia Axillary sheath · Axillary fascia · Brachial fascia · intermuscular septa (Lateral, Medial) Other spaces (Quadrangular space, Triangular space, Triangular interval) Forearm Anterior superficial: pronator teres · palmaris longus · flexor carpi radialis · flexor carpi ulnaris · flexor digitorum superficialis deep: pronator quadratus · flexor digitorum profundus · flexor pollicis longus Posterior superficial: mobile wad (brachioradialis, extensor carpi radialis longus and brevis) · extensor digitorum · extensor digiti minimi · extensor carpi ulnaris deep: supinator · anatomical snuff box (abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus) · extensor indicis Fascia Bicipital aponeurosis · common tendons (Extensor, Flexor) · Antebrachial fascia Other Cubital tunnel Hand Lateral volar thenar (opponens pollicis, flexor pollicis brevis, abductor pollicis brevis) · adductor pollicis Medial volar hypothenar (opponens digiti minimi, flexor digiti minimi brevis, abductor digiti minimi) · palmaris brevis Intermediate lumbrical · interossei (dorsal, palmar) Fascia posterior: Extensor retinaculum · Extensor expansion anterior: Flexor retinaculum · Palmar aponeurosis M: MUS, DF+DRCT anat (h/n, u, t/d, a/p, l)/phys/devp/hist noco(m, s, c)/cong(d)/tumr, sysi/epon, injr proc, drug (M1A/3)

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)

Dansk (Danish)
1.
n. - arm

idioms:

• arm in arm    arm i arm
• arm of a river    flodforgrening
• arm of the river    flodens forgrening
• arm of the sea    havets forgrening
• arm of the service    våbenart
• arm wrestling    lægge arm
• at arm's length    på afstand, fra livet, på arms afstand
• within arm's reach    inden for rækkevidde

2.
v. intr. - bevæbne sig
v. tr. - bevæbne, opruste
n. - våben

Nederlands (Dutch)
arm, (vuur)wapen, mouw, (boom)tak, legerafdeling, armleuning, slinger, (mv) wapenschild, (zich) bewapenen, bom instellen om te ontploffen, een hart onder de riem steken, voorzien van, zich op de strijd voorbereiden

Français (French)
1.
n. - (Anat) bras, branche (de monture), manche (d'un manteau), accoudoir, manivelle

idioms:

• arm in arm    bras dessus bras dessous
• arm of a river    bras de fleuve
• arm of the sea    bras de mer
• arm of the service    arme (section du service militaire)
• arm wrestling    bras de fer
• at arm's length    à portée de la main
• within arm's reach    à portée de la main, sous la main

2.
v. intr. - s'armer, prendre les armes contre
v. tr. - armer, (fig) s'armer (de patience), munir d'une tête d'ogive
n. - arme, armes (npl), armoiries (npl)

Deutsch (German)
1.
n. - Arm, Ärmel, Armlehne

idioms:

• arm in arm    mit verbundenen Armen
• arm of a river    Flußarm
• arm of the sea    Meeresarm
• arm of the service    Waffengattung
• arm wrestling    Armdrücken
• at arm's length    auf Distanz
• within arm's reach    griffbereit, in Reichweite

2.
v. - bewaffnen, rüsten
n. - Waffe, Waffengattung, (mil) Waffe, Kriegstaten, Militärdienst

Ελληνική (Greek)
n. - βραχίονας, χέρι (από τον ώμο και κάτω), μπροστινό πόδι ζώου, μανίκι, μπράτσο, χέρι (πολυθρόνας), κλάδος, τμήμα, όπλο, (στρατ.) όπλο, σώμα
v. - (εξ)οπλίζω/-ομαι, αρματώνω

idioms:

• arm in arm    αγκαζέ
• arm of a river    βραχίονας ποταμού, παραπόταμος
• arm of the river    βραχίονας ποταμού, παραπόταμος
• arm of the sea    (γεωγρ.) στένωμα κόλπου
• arm of the service    όπλο του στρατεύματος
• arm wrestling    μπρα ντε φερ
• at arm's length    σε απόσταση
• within arm's reach    κοντά, εκεί που φτάνει το χέρι μου

Italiano (Italian)
armare, braccio, arma, bracciolo

idioms:

• arm of a river    braccio di fiume
• arm of the river    braccio del fiume
• arm of the sea    braccio di mare
• arm of the service    arma
• arm wrestling    braccio di ferro
• as long as your arm    ben lungo
• at arm's length    a distanza
• to cost an arm and a leg    costare l'ira di Dio
• upper arm    braccio
• with open arms    a braccia aperte
• within arm's reach    a portata di mano

Português (Portuguese)
n. - braço (m), tentáculo (m), ramo (m) (de árvore)
v. - armar(-se), preparar(-se) para a guerra

idioms:

• arm in arm    de braços dados
• arm of a river    braço (m) de um rio
• arm of the river    braço (m) do rio
• arm of the sea    braço (m) de mar
• arm of the service    unidade (f) militar (Mil.)
• arm wrestling    braço (m) de ferro
• as long as your arm    muito grande
• at arm's length    afastado, inamistosamente
• to cost an arm and a leg    custar uma exorbitância
• upper arm    poder (m) superior
• with open arms    com os braços abertos, cordialmente
• within arm's reach    pronto para combate (Mil.), pronto para uma parada militar

Русский (Russian)
вооружать(ся), рука (от плеча до кисти), сила, власть, рукав, ручка, кронштейн

idioms:

• arm in arm    под ручку, вместе
• arm of a river    приток, рукав реки
• arm of the river    приток, рукав реки
• arm of the sea    залив
• arm of the service    род войск, отдельная часть вооруженных сил (напр. пехота)
• arm wrestling    борьба с руками на столе (спорт), арм-рестлинг
• as long as your arm    очень длинный
• at arm's length    на расстоянии
• to cost an arm and a leg    слишком дорого стоить
• upper arm    верхняя часть руки
• with open arms    с распростертыми объятиями
• within arm's reach    рядом

Español (Spanish)
1.
n. - armar, proveer de armas, brazo, pata delantera, arma, apoyabrazos, manga, astil

idioms:

• arm in arm    codo a codo
• arm of a river    brazo de un río
• arm of the sea    brazo de mar
• arm of the service    arma
• arm wrestling    lucha
• at arm's length    a prudente distancia
• within arm's reach    al alcance de la mano, al alcance

2.
v. intr. - armarse, apoyarse
v. tr. - armar, proveer de armas
n. - brazo, pata delantera, arma, apoyabrazos, manga, astil

Svenska (Swedish)
n. - arm, ärm, karm, försvarsgren
v. - beväpna, rusta

中文（简体）(Chinese (Simplified))
1. 臂, 扶手, 臂状物, 杆

idioms:

• arm in arm    挽臂, 臂挽著臂
• arm of a river    河湾
• arm of the river    河湾
• arm of the sea    海湾
• arm of the service    兵种
• arm wrestling    比腕力
• at arm's length    疏远, 在手臂伸得到的地方
• within arm's reach    够得着

2. 兵种, 武装起来, 用武器装备, 提供, 配备

中文（繁體）(Chinese (Traditional))
1.
n. - 臂, 扶手, 臂狀物, 桿

idioms:

• arm in arm    挽臂, 臂挽著臂
• arm of a river    河灣
• arm of the river    河灣
• arm of the sea    海灣
• arm of the service    兵種
• arm wrestling    比腕力
• at arm's length    疏遠, 在手臂伸得到的地方
• within arm's reach    夠得著

2.
n. - 兵種
v. intr. - 武裝起來
v. tr. - 用武器裝備, 提供, 配備

한국어 (Korean)
1.
n. - 팔, 권력

idioms:

• at arm's length    팔이 닿는 거리에, 가급적 멀리

2.
v. intr. - 전쟁 상태에 들어가다, 무장하다
v. tr. - 무장시키다, 견고히 하다, 을 활성화 하다
n. - 무기, 군사, 전쟁, 문서

日本語 (Japanese)
n. - 腕, 腕状のもの, ひじ掛け, 武器, 兵器, 武力, 紋章, 権力
v. - 武装させる, 武装する, 備えさせる

idioms:

• arm in arm    腕を組み合って
• arm of a river    川の支流
• arm of the sea    入り江, 入り海
• arm of the service    兵器
• arm wrestling    腕相撲, 腕ずもう

العربيه (Arabic)
‏(الاسم) ذراع, لسان البحر الداخل في البر, كم, قوه, سلاح ناري, شعبه من الجيش, حرب, الخدمه العسكريه (فعل) يحصن خلقيا, يزود بالأسلحه, يجهز للعمل‏

עברית (Hebrew)
n. - ‮זרוע, יד, שרוול, ענף, משענת-יד בכיסא, סניף של מוסד או חברה, לשון-ים, כוח הזרוע‬
v. intr. - ‮הזדיין, התחמש, הצטייד‬
v. tr. - ‮זיין, חימש, צייד, העביר (פצצה) למצב המאפשר התפוצצות‬
n. - ‮כלי-נשק, חיל (של צבא), ברבים: מקצוע הצבא‬

If you are unable to view some languages clearly, click here.

To select your translation preferences click here.