Unit 8 Arm

  1. Region of arm
    • Superiorly: communicates with the axilla
    • Inferiorly: a number of important structures pass between the arm and forearm
  2. 2 compartments formed by the medial and lateral intermuscular septa
    Anterior and posterior compartment
  3. 4 facts about anterior compartment
    • Contains muscles that predominantly flex the elbow joint
    • Contains brachial artery
    • Contains peripheral nerves derived from the anterior divisions of the brachial plexus
    • All the musculature is innervated by the musculocutaneous nerve
  4. 3 facts about the posterior compartment
    • Contains muscles that predominantely extend the elbow joint
    • Contains peripheral nerves derived from posterior divisions of the brachial plexus
    • Musculature in this region is innervated by the radial nerve
  5. Describe carrying angle of elbow
    • Angulation between long axis of humerus and long axis of forearm
    • Greater in women than men
    • Abnormal cases outside this range is called cubitus valgus/varus (varus is gunstock)
  6. The medial border of the humeral shaft continues distally and forms the:
    Medial supracondylar ridge
  7. The medial supracondylar shaft is:
    A roughened surface for the attachmet of muscles found in the anterior compartment of the forearm
  8. 5 Borders of the shaft
    • Medial border
    • Lateral border
    • Anteromedial surface
    • Anterolateral surface
    • Posterior surface
  9. Where is the deltoid tuberosity located?
    Anterolateral surface
  10. What extends and form the lateral supracondylar ridge distally?
    lateral border
  11. Where is the radial groove located?
    Posterior surface
  12. What lies in the radial groove?
    radial nerve and profunda brachii artery
  13. What is the medial epicondyle?
    A large bony protuberance, is the major palpable landmark on the medial side of the elbow. Bears a large oval impression for the attachment of muscles in the anterior compartment of the aforearm.
  14. What holds the goove for the ulnar nerve?
    Medial epicondyle
  15. What is the lateral epicondyle?
    Much less pronounced than medial epicondyle. Lateral to the capitulum and has a large irregular impression for the attachment of muscles in the posterior compartment of the forearm.
  16. Name the three fossa of the distal humerus
    • Radial fossa
    • Coronoid fossa
    • Olecranon fossa
  17. 2 facts about the radial fossa
    • least distinct of the fossae
    • Immediately superior to the capitulum of the anterior surface of the humerus
  18. Describe the coronoid fossa
    Adjacent to the radial fossa and is superior to the trochlea
  19. 2 facts about the olecranon fossa
    • Larget of fossae
    • Occurs immediately superior to the trochlea of the posterior surface of the distal end of the humerus
  20. Describe the capitulum
    • lateral in position and hemispherical in shape, it projects anteriorly and somewhat inferiorly and is not visible when the humerus is viewed from the posterior aspect
    • Articulates with the radius
  21. Describe the trochlea
    • Articulates with the ulna
    • Pulley shaped and lies medial to the capitulum
    • Medial edge is is more pronounced than its lateral edge
  22. Describe the shape of the head of the radius
    • Thick, disc-shaped structure oriented in the horizontal plane.
    • Circular superior surface, the fovea, is concave for articulation with the capitulum ofthe humerus
  23. Where is the next of the radius?
    Between the expanded head and the radial tuberosity on the shaft
  24. Describe the radial tuberosity and what attaches to it
    • Large blunt projection of the medial surface immediately inferior to the neck.
    • Roghened attachment for the biceps brachii tendon
  25. Describe olecranon process
    • Large projection of bone that extends proximally from the ulna.
    • Anterolateral surface is articular and contributes formation of trochlear notch (articulates with trochlea of humerus)
  26. Describe the coronoid process
    • Projects anteriorly from the proximal end of the ulna.
    • Superolateral surface is articular and participates, with the olecranon, in forming the trochlear notch
  27. Where is the ulnar tuberosity and what attaches there?
    At the apex of the anterior surface and is the attachment site for the brachialis muscle.
  28. Where is the radial notch?
    Lateral surface of the coronoid process
  29. Where is the supinator crest?
    Posterior margin of the fossa inferior to the radial notch.
  30. 3 considerations of corachobrachialis
    • Pierced by musculocutaneous n.
    • Brachial pulse palpable, medial and posterior to muscle
    • Proximal attachment blends with short head of biceps on corcoid process of scapula
  31. 4 considerations of biceps brachii
    • Tendon for long head is intrascapular and extrasynovial
    • Two joint muscle
    • Transverse humeral ligament
    • Deals with the bicipital aponeurosis
  32. What is the bicipital aponeurosis?
    Distal continuation of the common biceps tendon
  33. 2 functions of bicipital aponeurosis
    • Provides protection for the brachial artery and the median nerve in the cubital fossa
    • Alters the force distribution and decreases the pressure of the biceps tendon on the radial tuberosity
  34. 2 considerations for brachialis
    • Musculocutaneous nerve is anterior
    • Primary flexor of the elbow
  35. 2 facts of triceps brachii
    • Head is primary elbow extender
    • The long head of the triceps brachii is a joint muscle as it crosses the shoulder and the elbow
  36. What is the function and course of the brachial artery?
    • Provides the main arterial supply to the arm
    • Continuation of the axillary artery (receives name after passing the inferior border of teres major)
    • Ends in the cubital fossa anterior to the brachialis
    • Lies medial in the arm and passes inferolaterally to become anterior to the arm
    • Travels with median nerve which lies anterior to the artery, but becomes medial to it in the cubital fossa
  37. Branches of the brachial artery
    • Brachial profundus
    • Superior and inferior ulnar collateral artery
    • Radial artery
    • Ulnar artery
  38. Function of brachial profundus
    Provides blood supply to the posterior compartment of the arm
  39. Function of superior and inferior collateral ulnar artery
    Participate in the elbow anastomoses
  40. Function of radial artery
    At or near the cubital fossa under the bicipital aponeurosis
  41. Function of the ulnar artery
    At or near the cubital fossa under the bicipital aponeurosis
  42. Anastomoses of Superior ulnar collateral artery
    Posteral ulnar recurrent artery
  43. Anastomoses of Inferior collateral ulnar artery
    Anterior ulnar recurrent artery
  44. The middle collateral artery artery anastomoses with:
    interosseus recurrent artery
  45. The radial collateral artery anastomoses with the:
    radial recurrent artery
  46. Participants with the radial artery
    Radial recurrent
  47. Participants from the ulnar artery
    • Anterior and posterior ulnar recurrents
    • Interosseus recurrent from the common interosseus artery off the ulnar artery
  48. 3 functions of the Cephalic Vein
    • Travels primarily on the lateral surface of the arm
    • Travels superiorly to the deltopectoral groove
    • Travels with deltoid branch from the thoracoacromial trunk in the deltopectoral groove
  49. 2 facts about the basilic vein
    • Ascends into the inferior medial arm
    • Passes deeply, piercing the brachial fascia to merge with the accompanying veins of the brachial veins to form the axillary vein
  50. 2 Functions of the Median cubital vein
    • Commnication between the cephalic vein and the basillic vein
    • Serves as the site for venous puncture for drawing blood
  51. 4 Functions of Musculocutaneous nerves
    • Supplies all the muscles of the anterior compartment of the arm
    • Pierces the coracobrachialis
    • Travels between biceps brachii and brachialis
    • Becomes the lateral antebrachial cutaneous nerve
  52. 4 functions of median nerve
    • Initially lateral to the brachial artery
    • Crosses anterior as it travels with the brachial artery
    • Becomes medial to the brachial artery in the cubital fossa
    • Does not supply any muscles in the ARM
  53. 3 Functions of the ulnar nerve
    • Medial to brachial artery
    • Around the middle of the arm pierces the medial intermuscular septum (with the superior ulnar collateral artery)
    • Passes posterior to the medial epicondyle (easily palpated at this site "funny bone")
  54. What compartment does the radial nerve supply?
    Posterior compartment of the arm
  55. What does the radial nerve provide innervation for?
    • long head & lateral head of the triceps brachii prior to the spiral line
    • medial head of the triceps brachii from the spiral line
  56. What septum does the radial nerve pierce?
    intermuscular septum and enters the anterior compartment of the arm
  57. Where does the radial nerve divide into branches?
    Level of the lateral epicondyle
  58. What does the radial nerve divide into?
    Deep and superficial branches
  59. What is the function of the deep branch of radial nerve?
    Entirely muscular and articular and pierces the supinator
  60. What is the function of the superficial branch of the ulnar nerve?
    Superifical nerve is entirely cutaneous
  61. Name the 5 distributions of the cutaneous innervation
    • Intercostobrachial nerve
    • Medial brachial cutaneous - from medial cord
    • Superior lateral brachial cutaneous - from axillary n.
    • Inferior lateral brachial cutaneous - from radial n.
    • Posterior brachial cutaneous - from radial n.
  62. Define cubital fossa
    • Triangular area with 5 borders
    • Superior - imaginary line connecting med & lat epicondyles
    • Medially - pronator teres
    • Laterally - brachioradialis
    • Floor - brachiallis & supinator muscles
    • Roof - deep fascia reinforced with the bicipital aponeurosis
  63. Contents of cubital fossa
    • Lateral - biceps brachii tendon
    • Middle - brachial artery - commencement of radial and ulnar arteries
    • Medial - Median nerve
  64. Facts about humeroulnar and humeroradial
    • ginglymoid or hinge joints
    • uniaxial diarthrodial joint
    • 1 DOF
    • allows for flexion/extension
  65. What type of joint is the humeroulnar joint?
    Modified sellar
  66. What type of joint is the humeroradial joint?
    Modified ovoid
  67. Facts about proximal radioulnar joint
    • Uniaxial diarthrodial joint
    • trochoid (pivot) type joint
    • modified ovoid
    • 1 DOF
    • allows for pronation/supination
  68. Describe the trochlea
    • Covered with articular cartilage
    • Spool-shaped
    • trochlear groove spirals obliquely around the trochlea and divdes into a medial and lateral portion
  69. What is superior to the trochlea and lies on the anterior surface?
    coronoid fossa
  70. What is on the posterior surface near the trochlea?
    olecranon fossa
  71. Describe the capitulum
    • Covered with articular cartilage
    • Spherically shaped
    • Separated from the trochlea by the capitulotrochlear groove
  72. Where is the radial fossa located?
    Superior to the capitulum on the anterior surface of the humerus
  73. Describe the trochlear notch
    • Located on the anterior surface of the olecranon process
    • Concave-shaped
    • Contains a trochlear ridge that ridges in the trochlear groove
  74. The ulna contains what two notches?
    Trochlea and radial notches
  75. The joint capsule encloses what 3 joints?
    • Humerulnar joint
    • Humeroradial joint
    • Proximal radioulnar joint
  76. The medial (ulnar) collateral ligament of the elbow contains two/three parts
    • Anterior medial collateral ligament
    • Posterior medial collateral ligament
    • Transvere (oblique) ligament
  77. Function of Anterior medial collateral ligament
    • Attaches from the tip of the medial epicondyle of the humerus to the coronoid process of the ulna
    • Can be divided into functional bands
    • Limits primarily extension and resist valgus stress
  78. Functional consideration of Posterior medial collateral ligament
    • Attaches from the posterior surface of the medial epicondyle to the olcranon and coronoid process of ulna
    • Limits primarily flexion
  79. Functional consideration of Lateral (radial) collateral ligament of the elbow
    • Fan-shaped
    • Poorly demarcated
    • Extends from inferior lateral epicondyle of the humerus to the annular ligament and to the lateral aspet of the olecranon process
    • Resists varus stress
Card Set
Unit 8 Arm
Das arm