User:Heihaheihaha/尺神经

尺神经（Ulnar nerve）
点击图片放大-尺神经见于左下角
左上肢的神经（尺神经见于前臂，图中左侧）
基本信息
來源	C8, T1 (内侧束的分支)
支配	尺侧腕屈肌 指深屈肌尺侧半 小鱼际肌 第三和第四蚓状肌 [[[小指短屈肌（手）|小指屈肌]] ]骨间背侧肌 骨间掌侧肌 拇内收肌 等
标识字符
拉丁文	nervus ulnaris
《神经解剖学术语》

在人体解剖学中，尺神经行走于尺骨旁的一根神经，肘关节的尺侧副韧带与尺神经有关。该神经是人体最大的不受骨和肌肉保护的神经，其损伤较为常见。该神经直接连接到小拇指、无名指的尺侧半（与小拇指相邻的半侧），支配这些神经的掌侧、指尖的前部和后部，可能远至甲床。

在弯曲手臂的情况下撞击肱骨内侧髁可能刺激该神经并引起类似电击的短暂疼痛。

结构

手臂

尺神经起自脊神经C8-T1的神经根（有时也包含来自外侧索的C7的纤维）。

The ulnar nerve originates from the C8-T1 nerve roots (and occasionally carries C7 fibers which arise from the lateral cord), which then form part of the medial cord of the brachial plexus, and descends medial to the brachial artery, up until the insertion point of coracobrachialis muscle (middle 5 cm over the medial border of the humerus). Then, it pierces the medial intermuscular septum and enters the posterior compartment of the arm, accompanied by superior ulnar collateral vessels. It runs at the posteromedial aspects of the humerus, passing behind the medial epicondyle (in the cubital tunnel) at the elbow, where it can be palpated by hand.

前臂

The ulnar nerve is not a content of the cubital fossa. It enters the anterior (flexor) compartment of the forearm between the two heads of flexor carpi ulnaris, and lies along the lateral border of the flexor carpi ulnaris. The ulnar nerve runs between the flexor digitorum superficialis (laterally) and flexor digitorum profundus medially. Near the wrist, it courses superficial to the flexor retinaculum of hand, but covered by volar carpal ligament to enter the hand.

In the forearm it gives off the following branches:

• Muscular branches of ulnar nerve - supplies one and a half muscles (flexor carpi ulnaris and the medial half of flexor digitorum profundus)
• Palmar branch of ulnar nerve - arises from the middle part of the forearm and supplies the skin over the hypothenar eminence.
• Dorsal branch of ulnar nerve - arises from 7.5 cm above the wrist, winds backwards to supply the skin of the proximal part of the ulnar one and half fingers and the adjoining area between the fingers.
• Articular branches are given off to the elbow joint.

手

尺神经在手部的分支

Ulnar nerve enters the palm of the hand via the Guyon's canal, superficial to the flexor retinaculum and lateral to the pisiform bone.

Here it gives off the following branches:

• Superficial branch of ulnar nerve - supplies the palmaris brevis and gives digital branches to the medial one and a half fingers.
• Deep branch of ulnar nerve - It accompanies the deep branch of the ulnar artery. It passes backwards between the abductor digiti minimi, flexor digiti minimi, and opponens digiti minimi, supplying all the three muscles, and lying on the hook of hamate bone. It then turns laterally, supplying the 3rd and 4th lumbricals and all the palmar interossei muscles and dorsal interossei of the hand. It terminates by supplying the adductor pollicis.
• Articular branches to the wrist.

功能

Ulnar nerve is also known as "musician's nerve" as it controls the fine movements of the fingers.

感觉

右上肢的皮肤神经支配。浅蓝色的区域受尺神经支配

The ulnar nerve also provides sensory innervation to the fifth digit and the medial half of the fourth digit, and the corresponding part of the palm:

• Palmar branch of ulnar nerve - supplies cutaneous innervation to the anterior skin and nails
• Dorsal cutaneous branch of ulnar nerve - supplies cutaneous innervation to the dorsal medial hand and the dorsum of the medial 1.5 fingers

运动

尺神经及其分支支配前臂和手部的以下肌肉：

• An articular branch that passes to the elbow joint while the ulnar nerve is passing between the olecranon and medial epicondyle of the humerus
• In the forearm, via the muscular branches of ulnar nerve:
  • Flexor carpi ulnaris
  • Flexor digitorum profundus (medial half)
• In the hand, via the deep branch of ulnar nerve:
  • Hypothenar muscles
    • Opponens digiti minimi
    • Abductor digiti minimi
    • Flexor digiti minimi brevis
  • The third and fourth lumbrical muscles
  • Dorsal interossei
  • Palmar interossei
  • Adductor Pollicis
  • Flexor pollicis brevis (deep head)
• In the hand, via the superficial branch of ulnar nerve:
  • Palmaris brevis

临床意义

The ulnar nerve can suffer injury anywhere between its proximal origin of the brachial plexus all the way to its distal branches in the hand. It is the most commonly injured nerve around the elbow. Although it can be damaged under various circumstances, it is commonly injured by local trauma or physical impingement ("pinched nerve"). Injury of the ulnar nerve at different levels causes specific motor and sensory deficits.

At the elbow

• Common mechanisms of injury: Cubital tunnel syndrome, fracture of the medial epicondyle of the humerus (causing direct ulnar nerve injury), fracture of the lateral epicondyle of the humerus (causing cubitus valgus with tardy ulnar nerve palsy), Driver's Elbow
• Motor deficit:
  • Weakness in flexion of the hand at the wrist, loss of flexion of ulnar half of digits, or the 4th and 5th digits, loss of ability to cross the digits of the hand. (Note: Motor deficit is absent or very minor in cubital tunnel syndrome as the ulnar nerve is compressed in the cubital tunnel, rather than transected.)
  • Presence of a claw hand deformity when the hand is at rest, due to hyperextension of the 4th and 5th digits at the metacarpophalangeal joints, and flexion at the interphalangeal joints.
  • Weakness of adduction of the thumb, which may be assessed by the presence of Froment's sign.
• Sensory deficit: Loss of sensation or paresthesiae in ulnar half of the palm and dorsum of hand, and the medial 1½ digits on both palmar and dorsal aspects of the hand

At the wrist

• Common mechanism: penetrating wounds, Guyon canal cyst (and other lesions)
• Motor deficit:
  • Loss of flexion of ulnar half of digits, or the 4th and 5th digits, loss of ability to cross the digits of the hand.
  • Presence of a claw hand deformity when the hand is at rest, due to hyperextension of the 4th and 5th digits at the metacarpophalangeal joints, and flexion at the interphalangeal joints.
  • The claw hand deformity is more prominent with injury at the wrist as opposed to a lesion higher up in the arm, for instance, at the elbow, as the ulnar half of the flexor digitorum profundus is not affected. This pulls the distal interphalangeal joints of the 4th and 5th digit into a more flexed position, producing a more deformed 'claw'. This is known as the ulnar paradox.
  • Weakness of adduction of the thumb, which may be assessed by the presence of Froment's sign.
• Sensory deficit: Loss of sensation or paresthesiae in ulnar half of the palm, and the medial 1½ digits on the palmar aspect of the hand, with dorsal sparing. The dorsal aspect of the hand is unaffected as the posterior cutaneous branch of the ulnar nerve is given off higher up in the forearm and does not reach the wrist.

In severe cases, surgery may be performed to relocate or "release" the nerve to prevent further injury.

其它图像

• 
  示脊神经臂丛
• 
  上臂中部横截面
• 
  前臂中部横截面
• 
  桡骨和尺骨远端横截面
• 
  手腕、手指横截面
• 
  尺动脉和桡动脉
• 
  右臂丛神经（锁骨下部分）位于腋窝；下面和前面观
• 
  右上肢正面观，示骨骼、动脉和神经的表面投影
• 
  右上肢后面观，示骨骼、神经的体表投影
• 
  尺神经
• 
  尺神经标记于图中
• 
  尺神经
• 
  尺神经
• 
  尺神经
• 
  臂丛深层解剖前外侧观

另见

本條目使用了部分解剖術語。

• 腋神经
• 正中神经
• 肌皮神经
• 桡神经

外部链接

• Cubital Tunnel Support Forums 互联网档案馆的存檔，存档日期2022-10-04.
• Anatomy figure: 05:03-15 at Human Anatomy Online, SUNY Downstate Medical Center - "The major subdivisions and terminal nerves of the brachial plexus."
• Anatomy figure: 07:04-04 at Human Anatomy Online, SUNY Downstate Medical Center - "Anterior view of the nerves, vessels, and superficial tendons that cross the left wrist."
• Anatomy figure: 08:03-07 at Human Anatomy Online, SUNY Downstate Medical Center - "Transverse section through the carpal tunnel and distal row of the carpal bones."
• 杜克大学医学中心整形外科計畫中的Ulnar nerve
• 堪薩斯大學醫學中心的手部人體工學
• 圖譜：hand_plexus at the University of Michigan Health System - "Axilla, dissection, anterior view"
• Overview at neuro.wustl.edu
• Shoulder Ulnar Nerve Entrapment
• 互联网档案馆的存檔，存档日期2006-09-06.