Anatomy of Musculoskeletal system- 1 PDF

Anatomy of Musculoskeletal system- 1 Upper Limb 1- Bones, Blood vessels, Nerves, joints & Shoulder, Pectoral region Dr Suresh.,MBBS.,MD Assistant Professor, HSS. Objectives At the end of the lecture, students are able to, 1. name the bones of the upper limb and their important landmarks....

Anatomy of Musculoskeletal system- 1 Upper Limb 1- Bones, Blood vessels, Nerves, joints & Shoulder, Pectoral region Dr Suresh.,MBBS.,MD Assistant Professor, HSS. Objectives At the end of the lecture, students are able to, 1. name the bones of the upper limb and their important landmarks. 2. discuss the brachial plexus formation and major nerves supplying the upper limb. 3. describe the major arteries and veins their course in upper limb. 4. classify the joints and discuss the synovial joint structures. 5. describe the various movements that take place at joints. 6. describe the attachments, nerve supply and actions of various pectoral and scapulohumeral muscles  UPPER LIMB Consist of Four segments Shoulder Arm Forearm Hand  BONES long bones have 2 ends (upper and lower) Most of upper limb bones are long bones, except the scapula & carpal bones Scapula is Flat bone Carpals is Short bones (small bones) Clavicle is modified Long bone. Inside Shaft is bone marrow (Medial) (Lateral) SCAPULA HUMERUS  Main nerves of upper limb Must remember these 5 nerves! Branches of brachial plexus Axillary nerve Radial nerve Musculocutaneous network. These 5 nerves supply nerve majority of upper limb Ulnar nerve Median nerve remember ARM, then UM  Brachial plexus Roots -> Trunk (Superior, Medial, Inferior) -> Anterior, Posterior Anterior and Posterior form Cords. Cords form Lateral, Posterial (Radial come from Posterial), Medial (Ulnar come from Medial).  Brachial plexus No need to remember Divisions, not important. But must remember Trunks and Cords, Roots, Terminal branches Axillary artery Lateral cord Medial cord of brachial plexus that's why called Musculo, bcos it supplies Muscles Mulsculo cutaneous nerve (Arm muscles) Ulnar nerve Median nerve (forearm muscles) (forearm muscles) Anterior aspect  Posterior aspect Axillary nerve (Arm muscles) supplies Deltoid (total 2 muscles) Radial nerve (Upper limb- posterior muscles) Joints Joints are unions or junctions between two or more bones or rigid parts of the skeleton Type of Joints : 1. Synovial joints – Synovial fluids to reduce friction freely mobile joints, covered by capsule. Ex. Shoulder joint, Knee joint 2. Fibrous joints- Less mobile joints, bone ends connected by fibrous tissue primary cartilaginous Ex- Sutures, 3. Cartilaginous joints- Bone ends are united by cartilages Primary – no movements Secondary – less movement Components of Synovial joint Bones Articular cartilage Osteoarthritis is damage of Articular Cartilage) Synovial cavity Synovial fluid Synovial membrane Capsule outside Ligaments are outside Capsule  1.Sternoclavicular joint Joints of the Upper Limb 2. Acromioclavicular joint 3. Shoulder joint (Glenohumeral joint) 3. Elbow joint Humero-ulnar joint Humeroradial joint 4. Wrist joint (Radiocarpal joint ) Radius, Scaphoid, Lunate, Triquetrum 5. Carpometacarpal joint 6. Metacarpophalangeal joint 7. Proximal and distal interphalangeal joint  Blood supply of upper limb Sub = below Below clavicle it will travel Blood Supply: Arteries from neck to armpit under clavicle. Subclavian (neck) Axillary (armpit) Brachial (arm) Radial (forearm) Lateral side Ulnar (forearm) Medial side Superficial & Deep Palmar arches deep lies closer to Muscles lies closer to skin  Superficial Skin Blood Supply: Veins Deep Muscles Fascia Bones SUPERFICIAL Brachial vein Basilic + Brachial => Axillary vein -> sometimes Subclavian Cephalic (arm-forearm) joins into Axillary -> Subclavian Medial aspect Basilic (arm-forearm) Median Cubital (elbow) SF. Palmar Venous Arch Digital Superficial veins drains skins and fascia of upper limb  Blood Supply: Veins Superior Vena Cava DEEP Subclavian (neck) branch into Superior Vena Cava Axillary (axilla) Deep veins drains muscles and bones Brachial (arm-elbow) Radial (forearm) Ulnar (forearm) Deep Palmous Venous arch  Lymphatic drainage not in Practical drain into Axillary group of Lymph Notes Lymphatics are lymph vessels which carry a clear interstitial fluid called lymph. The lymphatic system provides an alternative route for interstitial fluid to return to the Axillary group Cubital lymph venous system. nodes of lymph nodes Plays role in defense mechanism  BONES OF UPPER LIMB Acromial end Clavicle Transmits part of the weight of upper limb to the axial skeleton. (trunk) weakest point that fractures Medial end Lateral end The lateral or acromial end of the bone is flattened and articulates with the medial side of the acromion process of scapula Superior view Medial or sternal end is enlarged and Sternal articulates manubrium sternum Subclavian Groove Lateral end Inferior view https://aclandanatomy-com.singaporetech.remotexs.co/MultimediaPlayer.aspx?multimediaId=10528033 SCAPULA HUMERUS cos usually Bicipital Groove aka Biceps tendon here fracture here Figure of 8 Articulates with Radius Articulates with Ulnar Scapula Projections are called Processes Anterior view Posterior view Superior angle Lateral angle wider Supra Spinous Fossa Root of Spine Subscapular Fossa Spinous Process aka Spine Infra Spinous Fossa Medial border aka Vertebral border Lateral border lies closer to Armpit Therefore Axillary border Inferior angle  Scapula Lateral view Coracoid process Acromian process Glenoid cavity has a bit of depression https://aclandanatomy- com.singaporetech.remotexs.co/Multimedia Player.aspx?multimediaId=10528033  Left humerus Humerus Anterior aspect Posterior aspect Head always faces Media Median Ulnar nerve Olecranon always Medial fossa Humerus upper end Groove aka Sulcus Travel out of Radial Nerve (rough area) https://aclandanatomy- com.singaporetech.remotexs.co/MultimediaPlayer.aspx?multimediaId=10528065 Humerus lower end  Muscles of upper limb Pectoral region Three muscles: Pectoralis major Pectoralis minor Serratus anterior  Pectoralis major Origin: (Proximal attachments) towards body Medial half of clavicle and anterior surface of sternum, first seven costal cartilages, Insertion: (Distal attachments)away from body Proximal part of humerus (lateral lip of intertubercular groove) Innervation: Lateral lip of groove Medial and lateral pectoral Medial nerves Action: Moving towards body Turning outwards on transverse plane Adduction, medial rotation, and moving forward anteriorially flexion of the humerus at the shoulder joint Proximal attachments (Origin): Pectoralis minor Anterior surfaces of the third, fourth and fifth ribs, and deep fascia overlying the related intercostal spaces Distal attachments (Insertion) Coracoid process Innervation: Medial pectoral nerve Action: Depresses tip of shoulder; protracts scapula Moving scapula forward Proximal attachment: Serratus anterior External surfaces of lateral parts of 1st–8th ribs Distal attachments: Medial border of scapula Innervation: Long thoracic nerve (C5, C6, C7) Action: Protracts scapula and holds it against thoracic https://sketchfab.com/3d-models/muscles-of-back-and-shoulder-region- wall; rotates scapula d0a6c51ec91e45c88a2d0f7337feb3be  PROXIMAL attachment from scapula DISTAL attachment in humerus = Move humerus Muscles of Scapula (INTRINSIC SHOULDER MUSCLES) Scapulohumeral muscles Subscapularis Remember shortcut: Students of SIT (Minor) Supraspinatus Rotator Infraspinatus Cuff Teres Minor Teres Major Deltoid Latissimus Dorsi (partial) Coracobrachialis https://aclandanatomy.com.singaporetech.remotexs.co/Multimedia Player.aspx?multimediaId=10528045 Muscles of Scapula: If DISTAL ATTACHMENT (INSERTION) on scapula = Move scapula EXTRINSIC SHOULDER MUSCLES Rhomboids Trapezius Pectoralis Minor Serratus anterior Levator Scapulae https://aclandanatomy.com.singaporetech.remotexs.co/Multim ediaPlayer.aspx?multimediaId=10528049 Muscles of Scapula Subscapularis Muscles of Scapula- Rotator cuff Muscles of Scapula- Rotator cuff  Muscles of Scapula- Muscle Proximal Distal Attachment Nerve supply Action Attachment (Insertion) (Origin) Subscapularis Subscapular fossa Lesser tubercle of Upper and lower Medially rotates humerus subscapular arm, helps to hold nerves head of humerus in glenoid cavity Supraspinatus Supraspinous fossa Greater tubercle Suprascapular Abduction of of humerus nerve of arm along with scapula Deltoid Infraspinatus Infraspinous fossa Greater Suprascapular Laterally rotates of tubercle of nerve arm scapula humerus Teres minor Middle part of Greater Axillary nerve Adducts and lateral lateral tubercle of rotation of arm border of scapula humerus  Deltoid Origin: Lateral third of clavicle; acromion and spine of scapula Insertion: Deltoid tuberosity of humerus (rough area of shaft) Nerve supply: Axillary nerve (C5, C6) Action: all actions involve deltoid Clavicular (anterior) part: flexes and medially rotates arm Acromial (middle) part: abducts arm and Adduction of shoulder Spinal (posterior) part: extends and laterally rotates arm Axillary nerve these 2 muscles will be paralysed if injured Branch of posterior cord Supply Deltoid and teres minor  Trapezius Origin: Medial third of superior nuchal line; External occipital protuberance; nuchal ligament; Spinous processes of C7–T12 vertebrae Insertion: same like Deltoid Lateral third of clavicle; acromion and spine of scapula Nerve supply: This is not Brachial nerve! Spinal accessory nerve from Cranial 11th nerve of Brain Action: Descending part elevates scapula Ascending part depresses scapula Middle part - retracts scapula  Muscles of Scapula = Move scapula Muscle Proximal Distal Attachment Nerve supply Action attachments (Insertion) (Origin) Levator scapulae Transverse Posterior surface of Dorsal scapular Elevates the scapula processes of C1 –C4 medial border of nerve vertebrae scapula Rhomboid minor Lower end of Posterior surface of Dorsal scapular nerve Elevates and retracts ligamentum nuchae medial border of the scapula and spinous scapula processes of C7 and T1 vertebrae Rhomboid major Spinous processes of Posterior surface of Dorsal scapular nerve Retract scapula and TII-TV vertebrae medial border of rotate scapula from the root its glenoid cavity of the spine of the inferiorly; fix scapula to the scapula to thoracic inferior angle wall Muscles of Scapula = Move scapula Levator scapulae Rhomboid minor Rhomboid major Joints of the Upper Limb 1.Sternoclavicular joint 2. Acromioclavicular joint 3. Shoulder joint (Glenohumeral joint)  Glenohumeral (shoulder) joint Ball-and-socket type of synovial joint Multi axial joint, permits a wide range of movement The large, round humeral head shallow glenoid cavity of the scapula Glenoid cavity is deepened and expanded peripherally by a fibrocartilaginous collar- glenoid labrum  LIGAMENTS i. Fibrous capsule ii. Gleno – humeral in between Greater & Lesser tubercle ligaments – superior, middle and inferior iii. Glenoidal labrum iv. Coraco – humeral ligament v. Transverse humeral ligament Movements ❖ FLEXION: - Pectoralis major, anterior fibres of deltoid, assisted by coracobrachialis and biceps brachii ❖ EXTENSION: - posterior fibres of deltoid and teres major - From full flexion, extension is by latissimus dorsi ABDUCTION: Supraspinatus, Deltoid ❖ ADDUCTION: - anterior and posterior fibres of the deltoid, pectoralis major, teres major, latissimus dorsi, coracobrachialis and long head of triceps ❖ MEDIAL ROTATION ie. Internal rotation Subscapularis, Pectoralis major; deltoid (clavicular part); latissimus dorsi; teres major ❖ LATERAL ROTATION ie. External rotation Infraspinatus, Teres minor; deltoid (spinal part)  Applied anatomy Dislocation of shoulder joint: - due to laxity of the ligaments and disproportionate articular surfaces. - axillary nerve is affected test the Deltoid muscle to know if Axillary nerve is intact or not Rotator Cuff Injuries During repetitive use of the upper limb above the horizontal line Recurrent inflammation of the rotator cuff, especially the relatively avascular area of the supraspinatus tendon Common cause of shoulder pain and results in tears of the musculotendinous rotator cuff. FROZEN SHOULDER (adhesive capsulitis) (Periarthritis shoulder) Adhesive fibrosis and scarring between the inflamed joint capsule of the glenohumeral joint, rotator cuff, subacromial bursa, and deltoid References Richard Drake A. Wayne Vogl Adam 2011. Gray's Anatomy for Students, 3rd edition Churchill Livingstone Standring, 2015 Gray’s Anatomy: The Anatomical Basis of Clinical Practice, 42nd Edition,, Churchill Livingstone Moore, K.L., Dalle,A.F. & Agur, A.M. 2013. Clinically Oriented Anatomy. 7th edition. Philadelphia: Lippincott Williams & Wilkins. Snell, R.S. 2011. Clinical Anatomy by Regions. 9th edition. Philadelphia: Lippincott Williams & Wilkins. Frederic H. Martini. Fundamentals of Anatomy & Physiology, Global Edition, 11th Edition: Pearson (instructor resources) Visible body applications http://anatomediaonline.com/amedia/index.html