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25 Cards in this Set
- Front
- Back
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What is meant by the term "rotator cuff"? What muscles and tendons form this?
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The muscles composing the rotator cuff (musculotendinous cuff around glenohumeral joint) are:
Teres Minor – rotator of humerus; help to hold humeral head in glenoid cavity Infraspinatus – rotator of humerus; help to hold humeral head in glenoid cavity Subscapularis – rotator of humerus; help to hold humeral head in glenoid cavity Supraspinatus – initiates and assists deltoid in abduction of arm; acts with other rotator cuff muscles The tendons forming the rotator cuff are the four tendons of the above muscles attaching to the humerus: * the first two of these (with question mark) don’t seem to have a particular name Teres Minor tendon (?) – attached at inferior facet on greater tubercle of humerus Infraspinatus tendon (?) – attached at middle facet on greater tubercle of humerus Subscapularis tendon - attached at lesser tubercle of humerus Supraspinatus tendon - attached at superior facet on greater tubercle of humerus |
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Pay special attention to the path of the suprascapular nerve and artery in relation to the suprascapular ligament.
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This nerve (C5-C6), arising from the superior trunk of the brachial plexus, runs laterally across the posterior triangle (region of the neck bounded by the sternocleidomastoid muscle anteriorly, trapezius muscle posteriorly and clavicle inferiorly) to supply the supraspinatus and infraspinatus muscles; it also sends branches to the glenohumeral joint.
The artery arises from the thyrocervical trunk and runs with the nerve to supply the same muscles. They both run through the scapular notch under the superior transverse scapular ligament. |
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What are meant by the terms flexion, extension, abduction, adduction, medial and lateral rotation?
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Flexion: 1 : a bending movement around a joint in a limb (as the knee or elbow) that decreases the angle between the bones of the limb at the joint
Extension: 2 : an unbending movement around a joint in a limb (as the knee or elbow) that increases the angle between the bones of the limb at the joint Abduction: To draw away from the midline of the body or from an adjacent part or limb. Adduction: To draw inward toward the median axis of the body or toward an adjacent part or limb. Medial Rotation: moving a part of a body around its long axis toward from the mid line of the body from the supine position Lateral Rotation: moving a part of a body around its long axis away from the mid line of the body from the supine position |
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What muscle (s) are responsible for abducting the humerus?
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Supraspinatus – initiates abduction to 15 degrees
Deltoid – continues abduction beyond 15 degrees Serratus Anterior – completes to swing scapula away |
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What arteries comprise the anastomotic network around the scapula?
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Intercostals – from thoracic aorta
Dorsal Scapular – from the subclavian a. Suprascapular – from thyrocervical trunk Transverse Cervical – from thyrocervical trunk Circumflex Scapular – from subscapular a |
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Identify the superficial veins. Where is a frequent location for the administration of material via a venipuncture?
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Cephalic vein – drains anterolateral portion of arm from dorsal venous network of hand to drain into axillary v. after passing through the deltopectoral triangle between the pec major and deltoid muscles
Basilic (Gr. Royal - King sized) vein – drains anteromedial portion of arm from dorsal venous network of hand to eventually join accompanying veins of brachial artery to form axillary v. Median Cubital vein – commonly used for venipuncture – joins cephalic v. and basilic v. at level of elbow Median vein of forearm – ascends in the forearm between the cephalic and basilic veins to join basilic vein in the cubital fossa Perforating veins – form communications between deep and superficial veins |
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What are the borders of the axilla? What are the major contents?
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BORDERS
Apex of the axilla – entrance from neck to axilla; lies between the 1st rib, clavicle, and superior edge of the subscapularis Base of the axilla – formed by concave skin, cutaneous tissue, and axillary fascia extending from the arm to the thoracic wall Anterior wall – formed by pectoralis major and minor and the pectoral and clavipectoral fascia associated with them Posterior wall – formed chiefly by the scapula and subscapularis on its anterior surface and inferiorly by the teres major and latissimus dorsi Medial wall – formed by the thoracic wall (1st to 4th ribs and intercostal muscles) and the overlying serratus anterior Lateral wall – narrow bony wall formed by the intertubercular groove of the humerus CONTENTS (vessels and nerves going to and from the upper limb) Nerves – Brachial plexus Vessels – Axillary artery and its branches; Axillary vein and its branches; Five major groups of axillary lymph nodes (apical, pectoral, subscapular, humeral, and central) |
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What is the axillary artery a direct continuation of? Where does the axillary artery begin? What does it divide into?
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Axillary a. is a direct continuation of the subclavian artery. Axillary artery begins at the lateral border of the 1st rib and ends at the inferior border of the teres major to become the brachial artery. There are three sections of the axillary artery – details of this on p. 432 of Baby Moore.
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What is the brachial plexus? Where does it begin? What root values contribute to the plexus?
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Brachial plexus (L. Braid) is the major network of nerves supplying the upper limb. It is formed by union of anterior primary rami of C5 through C8 nerves and the greater part of the anterior ramus of the T1 nerve. Roots of the brachial plexus are located in the posterior triangle of the neck (defined in question #2 of Lab I above) and emerge from the scalene hiatus (triangular gap bounded by the anterior and middle scalene muscles and the 1st rib to which the muscles attach) to form three trunks:
Superior: C5 and C6 Middle: C7 Interior: C8 and T1 |
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Can you identify the "M" configuration of the lower part of the plexus? What are the major nerves that arise from it? What are their root values? What muscles do they innervate? What regions of skin do they carry sensation from?
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The “M” configuration refers to the lateral, posterior and medial cords which arise from the superior, middle and inferior trunks.
Major nerves arising from the 3 cords are: Musculocutaneous Inntervates: coracobrachialis, biceps brachii, and brachialis; continues as lateral cutaneous nerve of forearm Axillary Innervates: teres minor and deltoid; glenohumeral joint and skin over inferior part of deltoid Median Innervates: flexor muscles in forearm (except flexor carpi ulnaris, ulnar half of flexor digitorum profundus, and five hand muscles) Radial Innervates: triceps brachii, anconeus, brachioradialis, and extensor muscles of forearm; supplies skin on posterior aspect of arm and forearm via posterior cutaneous nerves of arm and forearm Ulnar Innervates: one and one half flexor muscles in forearm, most small muscles in hand, and skin of hand medial to a line bisecting 4th digit (ring finger) |
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The brachioradialis muscle is a flexor of the forearm. What evidence is there to suggest that evolutionarily it might have functioned as an extensor?
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Though a flexor of the forearm, the brachioradialis is located in the posterolateral (extensor) compartment and is innervated by the radial nerve along with the extensors.
THIS IS AN EXCEPTION TO THE RULE THAT ALL FLEXORS ARE IN THE ANTERIOR COMPARTMENT AND THAT THE RADIAL NERVE SUPPLIES ONLY EXTENSOR MUSCLES. |
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Where would you take an arterial pulse in the arm? Where would you place a stethescope when taking blood pressure? Why?
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You would take an arterial pulse via the brachial artery by feeling just beneath the bicep on the medial surface of the arm. When taking blood pressure, a stethoscope is placed over the artery in the cubital fossa. After occluding the artery, the pressure is released and systolic pressure is recorded as the pressure at which blood is first heard to spurt in the artery. Diastolic pressure is indicated by an absence of sound made by blood flowing through the artery.
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What type of joints are the proximal, middle and distal radio-ulnar joints?
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Proximal Radioulnar Joint (Trochoid)
• between head of radius and ring formed by radial notch of the ulna and the anular ligament • Synovial joint Middle Radioulnar Joint (Interosseus Membrane) • Important in weight transmission from radius to ulna in supination/pronation • Synarthrosis – more specifically a syndesmosis (?) Distal Radioulnar Joint (Uni-axial pivot joint) • Between head of ulna and concave ulnar notch of the lower end of the radius. Held together by articular disc and enclosed in articular capsule • Synovial joint |
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What is the location of the ulnar nerve to the distal portion of the humerus?
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The ulnar nerve passes down medial aspect of arm and runs posterior to medial humeral epicondyle of the humerus to enter forearm.
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Which nerve (s) lie deep to the flexor retinaculum within the carpal tunnel? Which nerve (s) lie superficial to the retinaculum?
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Deep – Median Nerve
Superficial – Ulnar Nerve See diagram in Baby Moore p. 469 |
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Where does the tendon of the profundus muscle insert? Where does the tendon of the superficialis insert? Where do the tendons of the lumbrical muscles insert? What do these muscles do?
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Profundus Muscle (Flexor digitorum profundus)
• Insertion (Proximal) – proximal ¾ of medial and anterior surfaces of ulna and interosseus membrane • Insertion (Distal) – Bases of distal phalanges of medial four digits • Action – flexes distal phalanges at distal interphalangeal joints of medial four digits; assists with flexion of hand Superficialis Muscle (Flexor digitorum superficialis) • Insertion (Proximal) – TWO HEADS o Humeroulnar Head – medial epicondyle of humerus, ulnar collateral ligament and coronoid process of ulna o Radial Head – superior half of anterior border of radius • Insertion (Distal) – Bodies of middle phalanges of medial four digits • Action – flexes middle phalanges at proximal interphalangeal joints of medial four digits; acting more strongly, it also flexes proximal phalanges at metacarpophalangeal joints and hand Lumbrical Muscles (4 muscles in the palm of the hand; Lumbricus: L earthworm – i.e. these have an earthworm like appearance) • Insertion (Proximal) – each of the four muscles arises from the tendon of the flexor digitorum profundus muscle • Insertion (Distal) – each muscles inserts on the base of the digit to which the tendon passes • Action – flex the digits at the metacarpophalangeal joints and in combination with the interossei, extend the interphalangeal joints |
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What is meant by terms "extrinsic" and "intrinsic" muscles of the hand?
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Extrinsic hand muscles have their muscle bellies on the forearm. The two extrinsic groups are the long flexors and extensors.
The Intrinsic muscle groups are the thenar and hypothenar muscles (thenar referring to the thumb, hypothenar to the little finger), the interosseus muscles (between the metacarpal bones, four dorsally and three volarly) and the lumbrical muscles. These muscles arise from the deep flexor (and are special because they have no bony origin) and insert on the dorsal extensor hood mechanism. |
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What nerve(s) carry sensation from the dorsum of the hand? The palmar surface of the hand?
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Radial Nerve via its branch, the superficial branch of the radial nerve, carries sensation from the lateral 2/3 of the dorsum of the hand, the dorsum of the thumb and the proximal parts of the index and middle fingers.
Median Nerve carries sensation from the entire palmar surface, the sides of the first three digits, the lateral half of the fourth digit and the dorsum of the distal halves of those digits. Ulnar Nerve gives off dorsal and palmar branches which carry sensation from the medial side of the palm AND medial side of the dorsum of the hand, the fifth digit, and medial half of the fourth digit. |
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How many carpal bones are there? What are their names?
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There are 8 carpal bones:
From lateral to medial, the 4 bones in the proximal row are. . . Scaphoid – boat shaped Lunate – moon shaped Triquetrum – a three-cornered bone (L. triquetrus) Pisiform – pea shaped bone lying on palmar surface of triquetrum From lateral to medial, the 4 bones in the distal row are. . . Trapezium – four sided bone Trapezoid – wedge shaped bone Capitate – bone with a rounded head Hamate – wedge shaped with a hooked process (hook of hamate) |
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What are the thenar muscles?
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Abductor Pollicus Brevis
Flexor Pollicus Brevis Opponens Pollicus These muscles form the thenar eminence on the lateral surface of the palm and are chiefly responsible for the opposition of the thumb. |
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How many muscles will move the thumb?
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The following muscles are involved in the following movements of the thumb. . .
Abduction: Abductor pollicus longus (APL) Abductor pollicus brevis (APB) Adduction: Adductor pollicus Extension: Extensor pollicus longus (EPL) Extensor pollicus brevis (EPB) APL Flexion: Flexor pollicus longus Flexor pollicus brevis Opposition: Opponens pollicus Flexor pollicus brevis Adductor pollicus Flexor pollicus longus** **Increases pressure between the pulps of the fingers |
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What is meant by the term "anatomical snuff box"? What forms its borders? What is its main "component"?
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The anatomical snuff box is a depression on the back of the hand, just beneath the thumb, that is formed by three tendons (APL - anteriorly, EPB - anteriorly and EPL - posteriorly). The main component is the radial artery lying on the floor of the snuffbox.
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What is meant by the term "synergistic muscle activity"? Could you give an example of this?
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A synergist complements the action of a prime mover (main muscle activated during a specific movement of the body), for example, by preventing movement of the intervening joint when a prime mover passes over more than one joint.
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What are the functions of the lumbrical muscles? What are their innervations? What common clinicopathology of the hand are these muscles involved in?
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The lumbricals flex the digits at the MCP joints and, in combination with the interossei, extend the interphalangeal joints.
Lumbricals 1 & 2 (work with fingers 1&2): Median Nerve (C8-T1) Lumbricals 3 &4 (work with fingers 3&4): Deep branch of Ulnar Nerve (C8-T1) The lumbricals are often involved in the etiology of carpal tunnel syndrome – median nerve entrapment in the carpal tunnel (passageway deep to the flexor retinaculum between the tubercles of the scaphoid and trapezoid bones on the lateral side and the pisiform and the hook of hamate on the medial side). |
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The shoulder joint is classified as what general type of joint? Be able to compare it to another similarly structured joint in the body
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Glenohumeral joint is a ball and socket synovial joint between the humeral head and the glenoid cavity of the scapula.
Comparisons to Acetabulofemoral joint (hip) - shallow fossa for articulation (shoulder) vs. deep (hip) - greater range of movement (shoulder) - more stable to support weight (hip) |
