Upper Limb Anatomy: Blood Supply, Veins, and Muscles PDF

general blood supply vessels that supply various compartments Anatomy 534 Upper Limb 1 52 The Upper Limb Digrans General Features...

general blood supply vessels that supply various compartments Anatomy 534 Upper Limb 1 52 The Upper Limb Digrans General Features IN EXIM The upper limb is suspended from the bony shoulder (pectoral) girdle that links it to the trunk. The region between the shoulder joint and the elbow is the arm or brachium. The region below the elbow is the forearm or antebrachium which is joined to the hand at the wrist Blood Supply The blood supply ascends from the thoracic cavity off the aortic arch (varies on each side) Emma motor.pro a dded war M.siii The main vessel that distri- butes blood to the upper limb is the subclavian l artery. It passes over the iies t surface of the first (R1) rib and into the axilla. Here it is referred to as the axillary a. On leaving the mi.int axilla and entering the arm it becomes the brachial a. Holferiorside Just below the elbow the I brachial a. terminates by bifurcating into the ulnar Artery of Hand and radial aa. which pass through the anterior part of T.iiiiiiiiii.it the forearm. These vessels m unite again in the hand via superficial and deep palmar arches. Anterior y view The main arterial vessels venae lie in the anterior part of the limb, the posterior commitantes aspects being supplied by a number of important Canon branches: The scapular region receives blood from the subclavian and axillary aa. The back of the arm is supplied by the profunda brachii; the posterior forearm by the posterior interosseous a. (off the ulnar a.)  Anatomy 534 Upper Limb 1 53 Venous Drainage The deep structures of the limb are drained by veins which are often paired and extend alongside the arteries (venae comitantes). They eventually form, or open into, the axillary v. that becomes the subclavian v. as it enters the thorax. The superficial structures are drained by a number of subcutaneous vv. that also empty into the axillary v. The main superficial vv. are: The dorsal and palmar digital vv. which drain to irregular dorsal venous network on the dorsum of the hand. From the medial and lateral aspects of this network ff fe ial yffffff.IT two veins ascend into the forearm: The basilic v. (medially) ascends to the middle of the arm where it pierces the fascia and passes deep to contribute to the formation of the axillary v. Laterally, the cephalic v. passes onto the anterior aspect of the forearm. In the cubital fossa it communicates with the basilic v. via the median cubital v. (short, visible and immobile). The cephalic v. continues up the lateral side of the arm, into the deltopectoral groove where it pierces the deep fascia and joins the axillary v. media thumbside gyp flails Dorsalside Anatomy 534 Upper Limb 1 54 A median vein of the forearm is also often prominent. It joins the median cubital v. superiorly. The Median Cubital Vein Due to the incidence of withdrawing blood from this large superficial vein, its anatomical relationships are important All the superficial veins lie above (superficial to) the deep investing fascia of the upper limb. adoption.info aohd'assistance iaidooaa.io In the cubital fossa, the cephalic vein lies lateral and the basilic vein medial - both are superficial to the deep investing fascia. The median cubital v. passes Effreasted.SN obliquely through the fossa accepting the median ante- brachial v. (median vein of here dggffTaaa Mar the forearm) superficial to the or bicipital aponeurosis - an aponeurotic layer of fascia arising from the tendon of are the biceps brachii. This apo- neurosis passes medially the across the fossa to fuse with Eu the deep fascia of the forearm. The brachial artery lies deep to this fascia that effectively separates it from the overlying median cubital vein. Anatomy 534 Upper Limb 1 55 Innervation The nerve supply descends from the cervical region to join the blood supply coracoff exoid in the axilla The skin over the shoulder is supplied by the supraclavicular nn. (C3,4) from e the cervical plexus (C1-4). Below this the aqnterior rami of C5-8 and T1 form the brachial plexus. The nerves that supply the remainder of the upper limb iiiiii J.gg arise from this plexus. The median, musculocutaneous and iiiii ulnar nn. supply the skin and muscles of the anterior (flexor) part of the limb. The axillary, radial and posterior iiii interosseous nn. supply the skin and muscles of the posterior (extensor) si part of the limb. iiigi the superficial to earn time tunnel carpal 1,111 Muscles That Connect the Upper Limb to the Trunk Muscles Arising From the Vertebral Column Posteriorly these muscles arise from the occipital bone, cervical, thoracic, lumbar and sacral spines, and the iliac crest. These muscles include: The trapezius rotates the scapulae when the limb is raised above head. It also stabilizes the shoulder in upper limb movements; "shrugs" (accessory n.) Anatomy 534 Upper Limb 1 56 The levator scapulae rotates the scapula with the rhomboids in the opposite direction to the trapezius. The rhomboideus major and minor stabilizes and braces the shoulder. Rotates the inferior angle of the scapula. The latissimus dorsi is an adductor of the upper limb. finesse.ae iiiii i e ie ftp.i A eleton Muscles Arising From the Thoracic Wall The pectoralis major adducts the arm with the latissimus dorsi. Also assists with medial rotation. The pectoralis minor pulls the scapulae forward. In respiratory distress it can reverse to raise ribs when the shoulder girdle is fixed. The serratus anterior draws the scapulae forward in pushing and forward-reaching movements; rotates the inferior angle of scapula laterally turning glenoid cavity upwards when arm is raised above the head.  Anatomy 534 Upper Limb 1 57 The subclavius steadies the clavicle. The sternocleidomastoid is primarily involved with tilting motions of the head. The clavipectoral fascia is a thickening of the deep fascia extending from the periosteum of the clavicle where it encloses the subclavius m. It fills the gap between the subclavius and the pectoralis minor as the costocoracoid membrane. It then splits to enclose the pectoralis minor. It blends with the axillary fascia. 3 scapula EWE S nator by Parasagittal Section Through The Thoracic Wall nf This image shows the relationships of the pectoral muscles and the clavi- pectoral fascia. Anatomy 534 Upper Limb 1 58 Muscles of the Scapular Region A group of short, mainly stout Antevi face muscles located between the scapula and upper humerus that are essential to the stability and movement of the shoulder joint. Together, the first 4 form the rotator cuff: The subscapularis stabilizes the head of the humerus in the shallow glenoid cavity. With stiff Poirot arm by the side, its attachment facilitates medial rotation of the humerus at the shoulder. Anterior ftp.ffhnrih.qgaff.mn.im. a Ety section Cross The supraspinatus stabilizes and prevents the head of the humerus from slipping down off the glenoid cavity. With the deltoid it can abduct the arm. The infraspinatus rotates the arm laterally as well as stabilizing the shoulder joint. The teres minor stabilizes as well as produces lateral rotation of the arm. Anatomy 534 Upper Limb 1 59 The tendons of the muscles of the rotator cuff surround the shoulder joint on all sides except inferiorly (common dislocation site). They keep the large head of the humerus applied to the shallow glenoid cavity The teres major adducts and medially rotates the arm. It can be thought of as a portion of the subscapularis that has migrated onto the dorsum of the scapula as it has a similar nerve supply (lower scapular n.) The deltoid forms the "cap" of the shoulder and provides a wide range of actions at the shoulder: anterior fibers flex the arm (swing it forward), posterior fibers extend it back behind the body, inter- mediate fibers are powerful abductors of the arm. Anatomy 534 Upper Limb 1 60 The Quadrangular and Triangular Spaces The configuration of the muscles below the shoulder allow a number of structures to pass from anterior to posterior regions of the axilla and arm. The quadrangular space: transmits the axillary n. and posterior circumflex a. The triceps hiatus medial to the shaft of the humerus: transmits the radial n. and profunda brachii a. The triangular space inferior to the quadrangular space: passes the circumflex scapular br. of the subscapular a. Axillary Artery The axillary a. is a continuation of the subclavian a. It begins at the lateral edge of R1 and becomes the brachial a. as it passes the lower border of the teres major The axillary a. is divided into 3 parts by the overlying pectoralis minor m. The number of the division is equivalent to the number of branches from that division: Anatomy 534 Upper Limb 1 61 - Branches from the first part: - superior thoracic artery supplies the pectoralis major & minor - Branches from the second part: - thoracoacromial artery is a short trunk that breaks up to supply the pectoral, acromial, clavicular and deltoid regions - lateral thoracic artery contributes substantially to the breast - Branches from the third part: - subscapular artery is the largest branch of the axillary a. and gives rise to numerous muscular branches that form an anastomosis around the scapula - the anterior and posterior circumflex humeral aa. form an anastomotic circle around the surgical neck of the humerus. The anterior is small. The posterior extends through the quadrangular space with the axillary n. to supply the shoulder joint and surrounding muscles