Axilla and Compartments of the Upper Limb PDF

The Axilla and Compartments of the Upper Limb Dr. Sean McWatt, PhD [email protected] © Danny Quirk Artwork Learning Outcomes By the end of this lesson, you will be able to… Identify and name the major regions, bones, and joints of...

The Axilla and Compartments of the Upper Limb Dr. Sean McWatt, PhD [email protected] © Danny Quirk Artwork Learning Outcomes By the end of this lesson, you will be able to… Identify and name the major regions, bones, and joints of the upper limb Identify and describe the borders and contents of the axilla Explain how muscles are grouped into compartments by thick fascia, and describe the shared features between muscles within the same compartment Identify the major arteries and veins of the upper limb Overview, Bones, and Joints Regions of the Upper Limb Deltoid region Shoulder Scapular region Arm Anterior and posterior compartments Axillary region Armpit Cubital fossa Elbow We will run through the anatomy of the upper limb according to these regions, Forearm from proximal to distal. Anterior and posterior compartments Carpal region Wrist Dorsal Palmar Hand Back Palmar and dorsal Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme Posterior view © 2010, Icon Learning Systems, LLC. A subsidiary of MediMedia, USA, Inc. All right reserved Bones of the Upper Limb Clavicle Sternoclavicular joint Shoulder joint The clavicle articulates with the manubrium of Scapula the sternum to form the sternoclavicular joint. The humerus articulates with the scapula Humerus proximally to form the shoulder joint, distinguishing the shoulder from the arm. Elbow joint The humerus articulates with the radius and Radius ulna distally to form the elbow joint, distinguishing the arm from the forearm. Ulna Wrist joint The carpal bones fill the space between Carpal bones We will name these later the radius and ulna, proximally, and the metacarpals, distally, to form the wrist joint Bones and joints of the that distinguishes the forearm from the hand. hand and digits We will name these later Anterior view Posterior view Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme The Axilla  Borders of the Axilla Starts at the first rib Pectoralis Ends at teres major m. major m. Pectoralis minor m. Serratus Anterior wall anterior m. Medial wall Axilla Subscapularis m. Posterior wall Cubital fossa The axilla is the largest of three neurovascular ‘funnels’ Latissimus Teres in the upper limb. Carpal tunnel dorsi m. major m. Posterior wall Humerus Posterior wall It is a triangular space in the armpit Lateral wall Anterior view Inferolateral view that is bordered by muscles. Drake, Gray’s Anatomy for Students, 2nd Ed., Agur and Dalley, Grant’s Atlas of Anatomy, 13th Ed. Copyright © 2009 by Churchill Livingstone Copyright © 2013 by Lippincott Williams and Wilkins Contents of the Axilla Tendons of muscles of the anterior compartment of the arm Biceps bracii m. (long and short heads) Coracobrachialis m. Axillary lymph nodes Intertubercular groove The axilla is packed with Axillary sheath: Axillary a. fat that surrounds the Axillary v. major veins, arteries, Brachial plexus nerves, and lymph nodes of the upper limb. Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme Tendons of muscles Subscapularis m. from the anterior compartment of the arm Latissimus dorsi and also travel through the teres major mm. lateral part of the axilla. Transverse view (inferior) Agur and Dalley, Grant’s Atlas of Anatomy, 13th Ed. Copyright © 2013 by Lippincott Williams and Wilkin Contents of the Axilla Major neurovascular structures that travel from the neck and thorax into the upper limb through the axilla include the axillary artery and brachial plexus, while the axillary vein and lymph nodes drain from the upper limb into the thorax through the axilla. The axilla is, therefore, a very action-packed and important region of the upper limb. Anterior view Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme Compartments What is a compartment? Compartments are groups of muscles that are contained by thick layers of connective tissue called fascia, which is resistant to stretch and actually contributes to force production. Muscles within the same compartment typically act synergistically on the joint(s) they cross. Each compartment usually In this example from the leg, has its own corresponding you can see that there are neurovascular bundle four compartments We’ll name them in Unit 4 (i.e., they share a common vein, artery, and nerve) Transverse view (inferior) Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme Compartments of the Upper Limb Posterior In the upper compartment limb, flexion Extension is anterior movement and extension is posterior movement Anterior compartment Flexion Arm Anterior compartment The arm and forearm are Posterior Flexion and each divided into anterior compartment pronation and posterior compartments Extension and Forearm supination Transverse views (inferior) Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme Compartments of the Upper Limb Posterior …which are derived from the compartment Radial n. brachial plexus Posterior compartment Radial n. Anterior compartment Medial part = Ulnar n. Musculocutaneous n. Anterior compartment Arm Middle part = Median n. Anterior Each compartment has specific compartment nerves associated with it… Forearm Transverse views (inferior) Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme Compartment Syndrome 1) Trauma or ↑ blood flow Pain Since the fibrous fascial sheaths that surround the compartments do not stretch, damage and swelling 4) Compressed 2) Swelling or blood and within a compartment can cause Fasciotomy nerve supply bleeding pressure to build up within it. This is Anterior approach called compartment syndrome. 3) Increased pressure The most common sites are in the leg and the forearm. Acute cases require surgery (fasciotomy); Anterior compartment however, it can also occur from Flexion and pronation overusing muscles or rapidly intensifying exercise which does not require surgery. Forearm Transverse view (inferior) Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme Arteries and veins Arteries of the Upper Limb Subclavian a. Axillary a. Axillary a. pulse point The subclavian a. branches off of the arch of the aorta on the left side and from the brachiocephalic Brachial a. Brachial a. trunk on the right side. pulse points It then changes its name as it Radial a. pulse point Subclavian aa. continues through the upper limb, becoming the axillary a. after it Radial a. crosses the first rib, and the Brachiocephalic trunk Aorta brachial a. after it crosses the teres major m.. It then splits into the https://tinyurl.com/y6au3f5x Ulnar a. radial a. and ulnar a. within the cubital fossa, which come together The deep veins follow the Palmar arches Deep and superficial to form deep and superficial arteries, but in reverse! They are named the same… palmar arches in the hand. Anterior view Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme Palmar Arches Radial a. Digital aa. Ulnar a. Palmar arches Deep and superficial Principis pollicis a. The deep and superficial palmar arches supply the hand and the digits (fingers). The index finger (2nd digit) usually serves as a landmark to distinguish blood supply originating from the radial a. versus ulnar a. Ulnar a. Radial a. Anterior (palmar) view Drake, Gray’s Anatomy for Students, 2nd Ed., Copyright © 2009 by Churchill Livingstone Clinical Allen’s Test: Assessment of vascular anomalies or occlusions in the hand 1. Ask patient to 3. Ask patient to open 5. Release pressure on 7. Repeat steps 1 – 4 make a fist their hand the radial a. 8. Release pressure on 2. Apply pressure to 4. Observe blanched 6. Observe colour return the ulnar a. radial a. and ulnar a. colour of palm to hand 9. Observe colour return to hand If colour returns in approximately 7 seconds, blood supply is adequate. © Dr. Nicole Ventura, McGill University Clinical Positive Allen’s Test: Incomplete palmar arches or vascular occlusions Using the Allen’s test, you can determine whether or not a patient has an occlusion (i.e., blockage) or branching variation in the palmar arches. Blood only returning to half of the hand, suggests that the arches are not fully patent. https://thoracickey.com/radial-artery-evaluation-before-coronary-artery-bypass-grafts  Deltopectoral Superficial Venous Drainage triangle/groove Axillary v. The superficial veins are important for performing blood draws. Cephalic v. Cephalic v. Veins have valves, which Axillary v. prevent backflow of blood Basilic v. Joining the brachial v. Median away from the heart. and running with the cubital v. brachial a. However, valves can be obstacles when attempting to draw blood. Basilic v. Dorsal venous arch (on dorsum of hand) Anterior views Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme Drake, Gray’s Anatomy for Students, 2nd Ed., Copyright © 2009 by Churchill Livingstone Summary By now, you should better understand how to… Identify and name the major regions, bones, and joints of the upper limb Identify and describe the borders and contents of the axilla Explain how muscles are grouped into compartments by thick fascia, and describe the shared features between muscles within the same compartment Identify the major arteries and veins of the upper limb  © [email protected]