The Axilla and The Arm

Lecture 28: 

Lecture 28 The Axilla & The Arm Cleyson Mupfiga

Axilla: 

Axilla Pyramidal space inferior to the shoulder joint Provides a passageway for vessels and nerves to reach the upper limb Cleyson Mupfiga HUB117 2011 2

Axilla – Walls: 

Axilla – Walls Apex Entrance from neck to axilla Lies between the 1 st rib, clavicle and superior border of scapula Base Formed by skin of the armpit Cleyson Mupfiga HUB117 2011 4

Axilla – Walls: 

Axilla – Walls Anterior wall Muscles – pectoralis major & minor, subclavius Fascia – clavipectoral and pectoral fascia Posterior wall Muscles – subscapularis , teres major and latissimus dorsi Medial wall Upper part of thoracic wall – 1 st to 4 th intercostal spaces and serratus anterior Lateral wall Humerus – intertubercular groove Cleyson Mupfiga HUB117 2011 5

Slide 7: 

Subscapularis Teres major Latissimus dorsi Pectoralis major Pectoralis minor Subclavius Clavipectoral fascia Clavicle

Contents: 

Contents The axilla contains: Axillary blood vessels Axillary artery and its branches Axillary vein and its tributaries Lymph nodes and lymphatic vessels Brachial plexus – cords and branches Fat Axillary blood vessels and brachial plexus are ensheathed into a neurovascular bundle by the axillary sheath Cleyson Mupfiga HUB117 2011 8

Slide 9: 

Brachial plexus Axillary a . Axillary v . Median n. Musculocutaneous n. Ulnar n. Long thoracic n. Pectoral nerves

Slide 10: 

Axillary lymph nodes Axillary a . Axillary v . Fat

Upper Limb Muscles: Arm: 

Upper Limb Muscles: Arm Arm extends from shoulder to elbow Two compartments – anterior & posterior Chief actions are at the elbow: anterior – elbow flexors; posterior – elbow extensors Some muscles act on the shoulder joint Anterior compartment Biceps brachii Brachialis Coracobrachialis Nerve supply: musculocutaneous n. Cleyson Mupfiga HUB117 2011 13

Slide 14: 

Biceps brachii Long head Short head Biceps tendon Aponeurosis of biceps brachii Coracobrachialis

Slide 15: 

Coracobrachialis Brachialis Ulna Radius Humerus Coracoid process Acromion process Musculocutaneous n.

Upper Limb Muscles: Arm: 

Posterior compartment Triceps brachii Anconeus Nerve supply – radial nerve Cleyson Mupfiga HUB117 2011 16 Upper Limb Muscles: Arm

Slide 17: 

Deltoid (cut) Lateral head Long head Triceps brachii Anconeus Olecranon process

Slide 18: 

Lateral head Long head Medial head Radial nerve Axillary nerve Suprascapular nerve Dorsal scapular nerve Anconeus Triceps brachii

Slide 20: 

Triceps brachii Lateral head Humerus Long head Medial head (a) Brachialis Short head Long head (a) Muscles of the arm Extensors Flexors Others Posterior compartment of arm (extends elbow); innervation: radial nerve Biceps brachii Anterior compartment of arm (flexes elbow); innervation: musculocutaneous nerve

Study Questions: 

Study Questions Describe the axilla under the following subheadings: location, shape, walls, and contents. List the muscles that cause flexion and extension of the elbow. Where are these muscles located? Describe the muscles in Q2 using the following subheadings: origin, insertion, action(s), and nerve supply. Cleyson Mupfiga HUB117 2011 21

Slide 22: 

The End