Anatomy Bones and Muscles · MU Pleven

226. Regio brachii posterior.

Covers the posterior compartment of the arm: its location and cylindrical shape, the skin and superficial fascia with their cutaneous nerve branches from the radial nerve, and the deep fascia. It then describes the superior neurovascular bundle of the radial nerve and deep brachial artery passing through the radial canal, and the inferior bundle of the ulnar nerve and superior ulnar collateral artery. A labelled picture of the radial canal's boundaries and contents is included.

Inside: 2 sections · 1 labelled picture · 16 flashcards · 2 min

Topic 225 of 236 in the MU Pleven syllabus for Anatomy Bones and Muscles (Medicine, Year 2). The free AceMed note covers it in 2 sections, about 273 words (2 min of reading), with 16 flashcards.

In this note

  1. Introduction
  2. Posterior Compartment:

Introduction

257,258

Posterior Compartment:

  1. 1. Location and Shape:
  • Situated behind the humerus.
  • Roughly cylindrical shape, rounder proximally.
  1. 2. Skin and Superficial Fascia:
  • Thicker and more movable skin compared to the anterior brachial region.
  • Well-pronounced superficial fascia connected to deep fascia by thin layer of loose connective tissue.
  • Contains branches of n. cutaneus brachii posterior, n. cutaneus brachii lateralis inferior, and n. cutaneus antebrachii posterior, originating from n. radialis.
  1. 3. Deep Fascia (Fascia Brachialis):
  • Considerable thickness, thins out over the tendon of m. triceps brachii.
  1. 4. Superior NVB:
  • Comprises n. radialis and a. profunda brachii.
  • Passes through canalis humerumuscularis, formed by sulcus nerviradialis humeri and the medial and lateral heads of m. triceps brachii.
  • N. radialis gives off cutaneous branches and branches for m. triceps brachii.
  • A. profunda brachii gives off collateral branches before continuing as a. collateralis radialis.
  • Exit the canal, pierce septum intermusculare laterale, and descend in the sulcus between m. brachialis and m. brachioradialis.
  1. 5. Inferior NVB:
  • Consists of n. ulnaris and a. collateralis ulnaris superior.
  • Crosses septum intermusculare mediale and descends behind it, lying on the medial aspect of m. triceps brachii.

The radial canal is a space located on the posterior surface of the humerus bordered by the radial groove on the humerus and the medial and lateral heads of the triceps brachii. It contains the radial nerve and the deep brachial vessels.

Boundaries

  1. 1 Floor: radial groove
  2. 2 Proximally and laterally: lateral head of triceps brachii
  3. 3 Distally and medially: medial head of triceps brachii

Content

  1. 4 Radial nerve
  2. 5 Profunda brachii artery
  3. 6 Deep veins of arm

Anterior view of the right arm (lateral head of the triceps brachii cut)

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