ANATOMY ANATOMY By Dr. THAAER MOHAMMED DAHER ALSAAD M.B.Ch.B.(MBBS) F.I.B.M.S.(Ph.D.) SPECIALIST IN GENERAL SURGERY SENIOR LECTURER IMS MSU
ARM AND HUMERUS Pectoral region
Pectoral regionTopographical Anatomy MIDAXILLARY LINE an imaginary vertical line passing through the middle of the axilla. used as a surface landmark for descriptive purposes. MIDCLAVICULAR LINE /(milk line) an imaginary vertical line passing through the midshaft of the clavicle used as a surface landmark for descriptive purposes.
DELTOPECTORAL/ clavipectoral fascia Is pierced by the following structures; Cephalic vein. Acromiothoracic artery. Lateral pectoral nerve.
DELTOPECTORAL TRIANGLE/ The clavipectoral triangle a triangle in the upper chest region that is bounded medially by the clavicle, superiorly by the deltoid muscle and inferiorly by the pectoralis major muscle this pierced by the cephalic vein on its course from the upper limb to join the axillary vein in the axilla. NIPPLE located superficial to the 4th intercostal space in the male and prepubertal female; areola is dark ring surrounding nipple, location of the left nipple may be used to help locate the apex of heart, which is approximately 8 cm from the midline in the left 5th intercostal space; a surface landmark used to place the stethoscope for auscultation of the bicuspid valve. SUPRASTERNAL NOTCH the notch located at the superior border of the manubrium of the sternum, between the sternal ends of the clavicles also known as: jugular notch. Topographical Anatomy
LATISSIMUS DORSI Origin; spinous processes of thoracic T7-T12, thoracolumbar fascia, iliac crest and inferior 3 or 4 ribs, inferior angle of scapula. Insertion; floor of intertubercular groove of the humerus. Nerve; thoracodorsal nerve (C6 - C8). Actions; adducts, extends and internally rotates the arm. Antagonist deltoid, trapezius Artery; thoracodorsal branch of the subscapular artery
PECTORALIS MAJOR ORIGIN;
anterior surface of the medial half of the clavicle.
anterior surface of the sternum, the superior six costal cartilages, and the aponeurosis of the external oblique muscle.
PECTORALIS MAJOR Insertion lateral lip of the bicipital groove of the humerus. Action Clavicular head, flexes the humerus Sternocostal head, extends the humerus
As a whole, adducts and medially rotates the humerus. It also draws the scapula anteriorly and inferiorly.
PECTORALIS MAJOR Nerve supply medial and lateral pectoral nerves (C5-T1). Clavicular head: C5 and C6Sternocostal head: C7, C8 and T1 Arterial blood supply pectoral branch of the thoracoacromial trunk. the deep fascia on its anterior surface should not be fused to the fascia of the mammary gland - if it is, this is an important clinical sign indicating breast disease (Latin, pectus = breast bone)
Poland's Syndrome /// is a congenital anomaly in which there is a malformation of the chest causing the pectoralis major on one side of the body to be absent. The latissimus dorsi and teres major also aid in adduction and medial rotation of the arm.
PECTORALIS MINOR ORIGIN; ribs 3-5 near their costal cartilages. INSERTION; medial border and superior surface of the coracoid process of the scapula.
PECTORALIS MINOR The Pectoralis minor is a thin, triangular muscle, situated at the upper part of the chest, beneath the Pectoralis major. Action It stabilizes the scapula by drawing it inferiorly and anteriorly against the thoracic wall. Nerve supply medial pectoral nerve (C8, T1). Arterial supply pectoral branch of the thoracoacromial trunk.
SERRATUS ANTERIOR ORIGIN; outer surface ribs 1-8 or 9 INSERTION; medial border of the scapula on its costal (deep) surface. Action it draws the scapula forward; the inferior fibers rotate the scapula superiorly. Nerve supply long thoracic nerve (from ventral rami C5-C7). Arterial supply lateral thoracic artery. Antagonist Rhomboid major, Rhomboid minor, Trapezius”
a lesion of long thoracic nerve will cause winging of the scapula (i.e., the medial border of the scapula falls away from the posterior chest wall and looks like an angel's wing) (Latin, serratus = to saw)The serratus anterior is occasionally called the "big swing muscle”
A patient with pronounced winging of the left scapula during active external rotation against resistance, typical of trapezius palsy Winging of the right scapula due to serratus anterior palsy, accentuated by active flexion of the arms
Subclavian groove On the medial part of the clavicle is a broad rough surface, the costal tuberosity (rhomboid impression), rather more than 2 cm. in length, for the attachment of the costoclavicular ligament. The rest of this surface is occupied by a groove, which gives attachment to the Subclavius; the coracoclavicular fascia, which splits to enclose the muscle, is attached to the margins of the groove. Not infrequently this groove is subdivided longitudinally by a line which gives attachment to the intermuscular septum of the Subclavius.
Inferior surface of the clavicle to 1st rib
at the junction of 1st rib and costal cartilage.
Inferior surface of middle 1/3rd of the clavicle (subclavius groove).
Nerve to subclavius C5-6 from the upper trunk.
depression of clavicle. The Subclavius protects the underlying brachial plexus and subclavian vessels from a broken clavicle.
FASCIA FASCIA – a sheet of fibrous tissue that envelopes the body beneath the skin and/or encloses muscles and groups of muscles.
Pectoral fasciainvests the pectoral muscle and is continuous with abdominal wall fascia. It leaves the lateral border of the pectoralis to become:
Axillary fascia that forms the floor of the axilla. Clavipectoral fascia descends from the clavicle to surround the pectoralis minor.
The lower clavipectoral fascia forms the suspensory ligament of the axilla which pulls the axillary fascia taught when the Upper Extremity is abducted
Scapular fascia: invests each muscle originating from the surface of the scapula (supra, infra- spinatus & subscapularis creating a tough fascial compartment. Muscle fibers originated from these fascial surfaces.
The brachial fascia ensheathes the arm and attaches inferiorly to the epicondyles and olecranon.
The medial and lateral intermuscular septa extend to the medial and lateral surface of the humerus.
This separates the arm into the anterior (flexor) and posterior (extensor) compartments.
The antebrachial fascia,interoseous membrane andthe lateral intermuscular septa isolate an anterior and posterior compartment in the forearm.
Cross section of the upper arm just below the level of insertion of the deltoid muscle
Coracobrachialis muscle ORIGINCoracoid process of scapula with biceps brachii .
Coracobrachialis muscle INSERTIONUpper half medial border of humerus, between the origins of the Triceps brachii and Brachialis. ACTIONFlexes and weakly adducts arm NERVEMusculocutaneous nerve (C5, 6, 7) (from lateral cord)
BRACHIALIS ORIGIN: anterior surface of the humerus, particularly the distal half of this bone. INSERTION: coronoid process and the tuberosity of the ulna. NERVE: Brachialis is innervated by the musculocutaneous nerve (C5 and 6), and radial nerve (C7) to a small lateral part of the muscle.
flexion at elbow joint.
BICEPS BRACHII The biceps is tri-articulate, meaning that it works across three joints. The most important of these functions are to supinate the forearm and flex the elbow. These joints and the associated actions are listed as follows in order of importance: Proximal radioulnar joint . Humeroulnar joint. Glenohumeral joint.
BICEPS BRACHII ORIGIN short head: coracoid process of the scapula. long head: supraglenoid tubercle. INSERTION; TENDONradial tuberosity. BICIPITTAL APONEUROSIS into deep fascia on medial part of forearm.
STRUCTURES PASSING THROUGH THE ANTERIOR FASCIAL COMPARTMENT Brachial Artery. Musculocutaneous Nerve. Median Nerve. Ulnar Nerve. Radial Nerve
TRICEPS BRACHII –
TRICEPS BRACHII - MEDIAL HEAD
TRICEPS BRACHII - LATERAL HEAD
TRICEPS BRACHI ORIGIN Long head: infraglenoid tubercle of scapula.Lateral head: posterior humerus.Medial head: posterior humerus. INSERTION olecranon process of ulna.
TRICEPS BRACHI NERVE SUPPLY Triceps is innervated by the radial nerve, C6, 7 and 8, with separate branches for each head (and axillary nerve (long head)). ACTION: extends forearm, caput longum adducts shoulder. Antagonist : Biceps brachii
STRUCTURES PASSING THROUGH THE POSTERIOR FASCIAL COMPARTMENT Radial Nerve. Ulnar Nerve. Profunda Brachii Artery. Superior and Inferior Ulnar Collateral Arteries.
Transverse section through the left arm at the junction of the proximal and middle thirds of the humerus: distal aspect
Transverse section through the left arm a little below the middle of the shaft of the humerus: distal aspect.
Transverse section through the left arm 2 cm above the medial epicondyle of the humerus: distal aspect.
CUBITAL FOSSA The cubital fossa is the region of the upper limb in front of the elbow joint. It is a triangular area with the following boundaries:
Laterally, brachioradialis muscle
Medially, pronator teres muscle
The base of the triangle, an imaginary line drawn between the medial and lateral epicondyles.
The floor of the fossa is formed by the supinator muscle laterally and the brachialis muscle medially.
The roof is formed by skin and fascia and is reinforced by the bicipital aponeurosis.