Axilla and Brachial Plexus PDF

# Shortcut to Anatomy - 1 year Physical Therapy ## AXILLA - **Definition:** pyramidal space between upper parts of arm and chest. ### Boundaries: - **Apex (cervico axillary canal):** - Connection between neck and apex of axilla. - Transmits vessels and nerves to upper limb. - It is b...

# Shortcut to Anatomy - 1 year Physical Therapy ## AXILLA - **Definition:** pyramidal space between upper parts of arm and chest. ### Boundaries: - **Apex (cervico axillary canal):** - Connection between neck and apex of axilla. - Transmits vessels and nerves to upper limb. - It is bounded by: - **Medial:** 1st rib. - **Anterior:** clavicle. - **Posterior:** scapula. - **Ant wall:** - Pectoralis Major. - Clavipectoral fascia. - Subclavius. - Pectoralis minor. - **Post wall:** - Subscapularis. - Latisimus dorsi. - Teres major. - **Med wall:** - Upper 5 ribs and intercostal muscles. - Upper part of serratus anterior. - **Lat wall:** - Upper part of shaft of humerus. - Coracobrachialis. - Biceps. - Bicipital groove of humerus ### Contents: - Axillary artery. - Axillary vein. - Brachial plexus - infraclavicular part. - Axillary lymph nodes. - Axillary fat. - Loose connective tissue. ### Base: - Skin. - Axillary fascia. ## BRACHIAL PLEXUS - **Network of nerves extending from the neck into the axilla.** - **Present in the posterior triangle of the neck and axilla.** ### Formation | Stage | Formation | |---|---| | Roots | Ant rami of (C5,6,7,8,T1) | | Trunks | - Upper: union of C5 & C6<br>- Middle: C7<br>- Lower: union of C8 & T1 | | Divisions | Each trunk divides into ant and post divisions | | Cords | - Lat (C5,6,7): union of ant divisions of upper and middle trunks<br>- Med (C8,T1): ant division of (lower) trunk<br>- Post (C5,6,7,8,T1): union of the 3 post divisions | ### Branches | | Branches | |---|---| | | - Nto rhomboids (C5)<br>- Nto serratus ant (C5,6,7)<br>- Nto subclavius (upper trunk, C5,6)<br>- Suprascapular N (upper trunk, C5,6) | | Lat | - Lat pectoral N (C5,6,7)<br>- Lat root of median N (C5,6,7)<br>- Musculocutaneous N (C5,6,7) | | Med | - Med pectoral N (C8,T1)<br>- Med root of median N (C8,T1)<br>- Med cutaneous N of arm (C8,T1)<br>- Med cutaneous N of forearm (C8,T1)<br>- Ulnar N (C7,8,T1) | | Post | - Upper subscapular N (C5,6)<br>- Lower subscapular N (C5,6)<br>- Axillary N (C5,6)<br>- N to latissimus dorsi (C6,7,8)<br>- Radial N (C5,6,7,8,T1) | - **NB:** - Branches of brachial plexus supply all the muscles of upper limb except trapezius. - The ulnar N receives fibers of C7 from the median N ## AXILLARY (CIRCUMFLEX) NERVE - **Root value:** C5,6. ### Begining: - from post cord of brachial plexus. ### Course and Relations: - It passes post to axillary artery. - Passes through quadrangular space. - Passes post to surgical neck of humerus. ### Branches and Distribution: - Ant branch: ant part of deltoid. - Post branch: - Post part of deltoid and teres minor. - Upper lat cutaneous N of arm: supply skin over deltoid. ### End: - deep to deltoid by dividing into ant and post branches. ### Injury of axillary nerve: - **Causes:** fracture surgical neck of humerus or dislocation of shoulder. - **Motor:** Paralysis of deltoid - loss of abduction 15-90°. - **Sensory:** loss of sensation over the deltoid.