Anatomy - Exam 2

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Anatomy - Exam 2
2012-11-04 18:40:26
Anatomy shoulder girdle superficicial back

Shoulder girdle, Superficial Back
Show Answers:

  1. What bones make up the shoulder girdle?
    • clavicle
    • scapula
    • humerus
  2. What are the joints of the shoulder girdle?
    • scapulothoracic
    • sternoclavicular
    • acromioclavicular
    • glenohumeral
  3. What joint attaches the UE to the axial skeleton?
  4. What is the purpose of the shoulder girdle?
    provides mobility and stability for the UE
  5. Describe the clavicle
    • connects manubrium and rib one to the acromion of scapula
    • acts as a strut to hold UE free of trunk
    • shaped like an "s" to improve strength
    • transmits force from UE to axial skeleton
  6. Where is the most common clavicular fracture and describe what happens to it
    • medial 2/3 and lateral 1/3 meet (where clavicle starts to flatten)
    • falls directly onto shoulder or onto outstretched hand
    • lateral fragments tend to drop down
    • medial piece help up by SCM
  7. Describe the scapula
    • covers about ribs 2-7
    • concave anteriorly
    • convex posteriorly
    • connects to clavicle at AC joint and humerus at GH joint
  8. What joint does the scapula connect to the clavicle?
    AC joint
  9. What joint does that scapula connect to the humerus?
    GH joint
  10. Describe the proximal humerus
    • head articulates at the glenoid fossa of the scapula
    • greater and lesser tubercles are separated by the bicipital groove
    • has anatomical and surgical neck
  11. Where is the most common location for a fracture on the humerus?
    • occur around the surgical neck
    • children may fracture epipheseal plate
    • neres and circumflex artery are at risk when Fx
  12. Describe all the walls of the axilla
    • apex: convergence of clavicle, scapula and rib 1
    • base: fascia and skin of armpit
    • anterior wall: pectoral muscles, anterior axillary fold - pec major
    • posterior wall: scapula and subscapularis muscle, posterior axillary fold - latissimus dorsi and teres major
    • lateral wall: humerus
    • medial wall: ribcage
    • neurovascular bundle: brachial plexus runs through the axilla
  13. What are the arteries in the shoulder girdle?
    • brachiocepahlic: neck (big arch)
    • subclavian: under clavicle
    • axillary: into armpit
    • superior thoracic: towards ribs
    • thoracoacromial: towards acromion
    • lateral thoracic: outside of ribs
    • subscapular: between superior and lateral thoracic
    • ant/post humeral circumflex: blood to head of humerus
  14. Describe the ST joint
    • scapulothoracic joint
    • articulations of scapula and thorax
    • not a true anatomic joint
    • movments are linked to SC and AC joint
    • movment available at ST joint
    • --elevation/depression
    • --abduction/adduction (protract/retract)
    • --upward/downward rotation
    • glenoid is source of reference
    • protected by muscle
    • --keep scapula following the contour of thorax as it moves
  15. What is the normal range for upward rotation of the ST joint?
    60 degrees
  16. Why does the scapula need to move when the ST joint moves?
    to keep glenoid fossa and head of humerus aligned and provide stability
  17. Scapulohumeral rhythm
    • coordinated movment of the GH and ST joint
    • rhythm occurs at a 1:2 ratio
    • --for every 3o of movement, 1o is generated by ST joing and 2o by the GH joint
    • GH joint always moves first
    • --1st 60o in flexion
    • --1st 30o in abduction
    • whether it is in the 1st 30o of GH abduction or its the fors 60o in flexion, the scapula is fixating itself in that it will proide a good BoS for furthuer motion
  18. What are the abnormal movements of the ST joint?
    • winging: lateral tilt
    • movement of the vertebral border of the scapula away from the thorax
    • tipping: upwards tilt
    • movement of the inferior angle of scapula away from the thorax
  19. Describe the SC Joint
    • sternoclavicular joint
    • only bony attachment of the shoulder girdle to the axial skeleton
    • plane synovial joint with 3 DoF
    • --elevation/depression
    • --protraction/retraction
    • --rotation
    • has sternoclavicular disc (fibrocartilage) to increase the contact of fairly inconfruent surfaces and acts as pivot point for movement and also help with force absorption
    • convex and concave joint surfaces allow for elevation/depression and protraction/retraction
  20. What are the 4 ligaments of the SC Joint?
    • anterior sternoclavicular
    • posterior sternoclavicular - check ant/post movment of head of clavicle
    • costalclavicular - check elevation and superior glide
    • interclavicular ligament - check depression and downward glide
  21. Describe the AC Joint
    • acromioclavicular joint
    • lateral end of clavicle and acromion process of scapula
    • plane synovial joint with 3 DoF
    • --small gliding and rotating movements
    • maintains connection between clavicle and scapula
    • helps scapula respond to movment and tild the glenoid cavity up or down
    • also allows for winging or tipping
  22. What are the 4 main ligaments of the AC joint?
    • helps maintain stability
    • superior acromioclavicular
    • inferior acromioclavicular: controls horizontal stability
    • coraclavicular: connects clavicle and coracoid process
    • --divided into 2 parts - trapizoid (lateral) and coronoid (medial)
    • coracoacromial ligament
  23. Describe the GH joint
    • glenohumeral joint
    • ball and socket joint with 3 DoF
    • --flexion/extention
    • --rotation in horizontal plane
    • --rotation in the sagittal plane
    • humeral head is at an angle to shaft of bone (angle of inclination) and points slightly posterior (angle of torsion)
    • capsule is taut superiourly and slack inferiorly and is reinforced to most on the anterior side
    • capsule is tighet when arm is down
    • anterior capsule is arranged in a "z" pattern
    • --superior, middle, inferior
    • coracohumeral ligament: connects coracoid process with greater tubercle and help support humerus against pull of gravity
  24. What is the glenoid labrum and its function?
    glenoid labrum is a connective tissue attached to edges of the glenoid cavity that serves to deepend to articular surface
  25. Where is the subacromial bursa?
    seperates supraspinatus tendon and head of humerus from the acromion process
  26. Where is the subscapular bursa?
    seperates scapula from ribcage
  27. What is the coracoacromial arch?
    • formed by acromion andcoracoacromial ligament
    • protects the trop of humeral head, the muscles, tendons, and bursae from trauma from above like the strap of a bookbag
    • also helps prevent the head of the humerus from slidingg superiorly if pushed upward
    • aka: 5th joint of shoulder
  28. What muscles are considered in the pectorial group?
    • pectorialis major
    • pectorialis minor
    • subclavius
    • serratus anterior
  29. pectorialis minor
    • origin: outersurface of upper margin of ribs 3-5
    • insertion: coracoid process
    • action: lowers lateral angle of scapula, pulls shoulder forward
    • innervation: medial pectoral
    • blood supply: thoracoacromial
  30. pectorialis major
    • origin: sternal half of clavicle, sternume to 7th rib, cartilages of the true ribs, aponeurosis of external obliques
    • insertion: lateral lip of bicipital groove of humerus
    • action: adducts shoulder, flexes and medially rotates
    • innervation: medial and lateral pectoral
    • blood supply: thoracoacromial
  31. Subclavius
    • origin: upper border of 1st rib and its cartilage
    • insertion: groove on under surface of clavicle
    • action: draws clavicle down and forward
    • innervation: nerve to subclavius
    • blood supply: thoracoacromial
  32. serratus anterior
    • origin: outersurface of upper 8 or 9 ribs
    • insertion: costal surface of vertebral border of scapula
    • action: abducts and upwardly rotates scapula and raises ribs when scapula is fixed
    • innervation and blood supply: long thoracic
  33. What muscles are in the superficial back?
    • trapezius
    • latissimus dorsi
    • levator scapulae
    • rhomboid major
    • rhomboid minor
  34. trapezius
    • upper fibers elevate scapula
    • middle bifers retract scapula
    • lower fibers upwardly rotate the scapula
    • origin: external occipital protuberance, superior nuchal line, nuchal ligament from spines of C7-12
    • insertion: lateral 1/3 of clavicle, spine of scapula, acromion
    • action: adducts scapula, tilts chin
    • innervation: spinal accessory
    • blood supply: descending scapula
  35. latissimus dorsi
    • orgin: spines of T6-16, lumbodorsal fascia, crest of ilium, muscular slips of lower 3 or 4 ribs
    • insertion: floor of bicipital groove or humerus
    • action: adducts, extends, and medially rotates shoulder
    • innervation: thoracodorsal
    • blood supply: descending scapula, subscapular
  36. levator scapulae
    • origin: transverse process of C1-C4
    • insertion: vertebral border of scapula between superior angle and root of spine of scapula
    • action: elevates scapula, ipsilateral lateral neck flexion if scapula is fixed
    • innervation: sorsal scapula
    • blood supply: descending scapula
  37. rhomboid major
    • origin: spinous process of T2-T5
    • insertion: medial border of scapula between spine and inferior angle
    • action: adduction and downward rotation of scpula
    • innervation: dorsal scapular
    • blood supply: descending scapula
  38. rhomboid minor
    • origin: ligamentum nuchae, sping of C7-T1
    • insertion: root of spine of scapula
    • action: adduction and downward rotation of scapula
    • innervation: dorsal scapular
    • blood supply: descending scapular
  39. scapular stabilization
    traps and rhomboids combine to stabilize the scapula
  40. What muscles are in the shoulder?
    • deltoids
    • teremes major
  41. anterior deltoid
    • origin: lateral 1/3 of clavicle
    • insertion: deltoid tuberosity
    • action: flexion and medial rotation of arm
  42. middle deltoid
    • origin: acromion
    • insertion: deltoid tuberosity
    • action: abduction of the GH joint
  43. posterior deltoid
    • origin: spine of the scapula
    • insertion: deltoid tuberosity
    • action: extension and lateral rotation of humerus
  44. teres major
    • origin: dorsal surface of inferior angle of the humerus
    • insertion: medial lip of bicipital groove
    • action:adductss, medially rotates and extends arm
    • innervation: lower subscapular
    • blood supply: scapular circumflex
  45. What muscles are in the rotator cuff?
    • teres minor
    • supraspinatus
    • infraspinatus
    • subscapularis
  46. teres minor
    • origin: upper 2/3 lateral border of scapula
    • insertion: lowest facet of greater tuberosity below infraspinatus
    • action: lateral rotation of GH joint
    • innervation: lower subscapular
    • blood supply: scapular circumflex
  47. supraspinatus
    • origin: supraspinous fossa of scapula
    • insertion: superior facet of greater tuberosity
    • action: assist deltoid in abducting upper arm, fixates head of humerus in glenoid cavity, secondary external rotation of head of humerus
    • innervation: suprascapular
  48. infraspinatus
    • origin: infraspinous fossa of scapula
    • insertion: middle facet of greater tuberosity
    • action: ER
    • innervation: suprascapular
    • blood supply: suprascapular and scapular circumflex
  49. subscapularis
    • origin: subscapular fossa
    • insertion: lesser tuberosity and capsule of shoulder joint
    • action: medially rotates humerus, draws if forward and down when raised
    • innervation: upper and lower subscapularis
    • blood supply: lateral thoracic and subscapularis
  50. What are the actions of the GH joint?
    • flexion/extension
    • abduction/adduction
    • internal/external rotation
  51. What are the actions of the AC joint?
    • upward and downward rotation
    • rotation in horizontal plane
    • reotation in sagittal plane
  52. What are the actions of the ST joint?
    • elevation/depression
    • protraction/retraction
    • upward and downward rotation
  53. What are the actions of the SC joint?
    • elevation/depression
    • protraction/retraction
    • rotation
  54. What provides blood to the surgical neck of the humerus?
    circumflex artery