Ch. 8 Pectoral Gridle

Question 1

Skeleton of Upper Limb

Answer 1

• each upper limb has 32 bones

- form pectoral girdle and free part

Question 2

Pectoral Girdle- Clavical

Answer 2

• convex in shape anteriorly near the sternal junction
• clavicle is concave anteriorly on its lateral edge near the acromion
• it is S shaped
• medial end articulates with the manubrium of the sternum forming the sternoclavicular joint
• lateral end articulates with the acromion forming the acromioclavicular joint
• acrominal end articulates with acromion of the scapula
• a coniod tubercle and impression for the costoclavicular ligament serve as attachments for ligaments

Question 3

Pectoral Girdle- Scapula

Answer 3

• shoulder blade, triangular in shape
• spine: large process on the posterior of the scapula that ends laterally as the acromion (splits into two)
• acromion: flattened lateral portion of the spine of the scapula
• coracoid process: a protuding projection on the anterior surface just inferior to the lateral aspect of the clavicle that tendons of muscle attach to
• glenoid cavity: shallow concavity that articulates with the head of the humerus to form the glenohumeral joint

Question 4

Appendicular Skeleton

Answer 4

• primary function is movement
• includes bones of the upper and lower limbs
• girdles attach the limbs to the axial skeleton
• girdles of bones that attach the upper and lower limbs to the axial skeleton:
• pectoral girdle consists of bones that hold upper limbs in place
• pelvic girdle consists of bones that hold lower limbs
• pelvic girdle is adaptive for various movements and muscle attachments
  free part of upper= (clavicle, scapula, humerus, radius, ulna, carpals, metacarpals, phalanges)

Question 5

Medial (vertebral) border

Answer 5

closest to the vertebral spine

Question 6

Lateral Border

Answer 6

closest to the arm, thick edge

Question 7

Superior Border

Answer 7

superior edge, joins vertebral border at superior angle

Question 8

Inferior Angle

Answer 8

where medial and lateral borders meet inferiorly

Question 9

Superior Angle

Answer 9

uppermost aspect of scapula where medial border meets superior border

Question 10

Subscapular Fossa

Answer 10

anterior concavity where the subscapularis muscle attaches

Question 11

Supraspinous Fossa

Answer 11

posterior concavity superior to the scapular spine, attachment site for supraspinatus muscle

Question 12

Infraspinous Fossa

Answer 12

Posterior concavity inferior to the scapular spine, site of infraspinatus muscle (shoulder)

Question 13

Shoulder Joint

Answer 13

• ball and socket joint formed by the head of the humerus and the glenoid cavity of the scapula
• articular cartilage
• coracohumeral, glenohumeral, transverse humeral ligaments
• glenoid labrum
• bursae
• flexion/extension, abduction/adduction, circumdation

Question 14

Muscles that Move the Pectoral Girdle

Answer 14

• stabilizing the scapula so it can function as a stable origin for the muscles that move that humerus
• scapular movements increase the range of motion of the humerus
• many humeral movements would not be possible without scapular movements accompanying those of the humerus
• muscles work in groups that are either synergistic or antagonistic

Question 15

Movements by muscles at the Scapula

Answer 15

• protraction, retraction, elevation, depression, superior rotation, inferior rotation

Question 16

Anterior Thoracic Muscles

Answer 16

Serratus Anterior: abducts scapula and rotates it upward
Pectoralis Minor: abducts scapula and rotates it downward
Subclavius: depresses and moves clavicle anteriorly and helps stabilize pectoral girdle

Question 17

Posterior Group Thoracic Muscles

Answer 17

Trapezius: superior rotate scapula, middle adduct, inferior depress, upward rotate
Levator Scapulae: elevates scapula and rotates it downward
Rhomboideus: elevates and adducts, stabilizes scapula, major- downward, minor- upward

Question 18

Scapular Notch

Answer 18

bring blood vessels to pectoral girdle

Question 19

Subclavius

Answer 19

• anterior thoracic muscle
• rib 1
• clavicle
• depresses and moves clavicle anteriorly and helps stabilize pectoral girdle

Question 20

Pectoralis Minor

Answer 20

• ribs 2-5
• coracoid process of scapula
• abducts scapula and rotates it downward

Question 21

Serratus Anterior

Answer 21

• ribs 1-8 or 1-9
• Vertebral border and inferior angle of scapula
• abducts scapula and rotates it upward

Question 22

Trapezius

Answer 22

• superior nuchal line of occipital lobe, ligamentum nuchae, and spines of C7-T12
• clavicle and acromion and spine of scapula
• superior fibers upward rotate scapula; middle fibers adduct scapula; inferior fibers depress and upward rotate scapula; superior and inferior fibers together rotate scapula upward, stabilizes scapula

Question 23

Levator Scapulae

Answer 23

• transverse processes
• superior vertebral border of scapula
• elevates scapula and rotates it downward

Question 24

Rhomboid Major

Answer 24

• spines of T12-T5
• vertebral border of scapula inferior to spine
• elevates and adducts scapula and rotates it downward; stabilizes scapula

Question 25

Rhomboid Minor

Answer 25

• spines of C7-T1
• vertebral border of scapula superior to spine
• elevates and adducts scapula and rotates it downward; stabilizes scapula

Question 26

Pectoralis Major

Answer 26

• clavicle, sternum, and costal cartilages of ribs 2-6 and sometimes of ribs 1-7
• greater tubercle and lateral lip of the intertubercular sulcus of humerus
• as a whole, adduct and medially rotates arm at shoulder joint, clavicular head flexes arm, and sternocostal head extends the flexed arm to side of trunk

Question 27

Latissimus Dorsi

Answer 27

• spines of T7-L5, crests of sacrum and ilium, ribs 9-12
• intertubercular sulcus of humerus
• extends, adducts, and medially rotates arm at shoulder joint; draws arms arm inferiorly and posteriorly

Question 28

Scapular Muscles the Move the Humerus

Answer 28

• Deltoid
• Subscapularis
• Supraspinatus
• Infraspinatus
• Teres Major
• Teres Minor
• Coracobrachialis