the Pectoral Girdle and Breast

Question 1

What is another name for the costocoracoid membrane?

Answer 1

clavipectoral fascia

Question 2

what is the enclosed structures of costocoracoid membrane

Answer 2

subclavius and the pectoralis minor

Question 3

what are the piercing structures of the costocoracoid membrane

Answer 3

medial and lateral pectoral nerves
pectoral branch of the thoraco acromial artery
cephalic vein

Question 4

List the rotator cuff muscles

Answer 4

infraspinatus
supraspinatus
teres minor
subscapularis

Question 5

Describe the arteries that participate in scapular anastomoses

Answer 5

Transverse cervical artery
Dorsal scapular artery (the anastomosing branch of the transverse cervical)
Suprascapular artery
Circumflex scapular artery (from subscapular artery of the third part of axillary)
Thoracodorsal artery (from subscapular artery of the third part of axillary)
Posterior intercostal arteries (from thoracic aorta)

Question 6

Arterial Supply of the breasts

Answer 6

1.perforating branches of internal thoracic artery at 2nd to 4th interspaces
2.perforating branches of 3rd to 5th intercostal artery
3. pectoral branches of the thoraco-acromial artery (2nd part of axillary artery)
4.branches of the lateral thoracic artery (2nd part of axillary artery)
5. branches of the subscapular (3rd part of the axillary artery)

Question 7

what part of the body is the pectoral lymph nodes responsible for

Answer 7

Pectoral nodes are found at the inferior border of the pectoralis minor, and it drains central and lateral breast

Question 8

Describe the nerve supply of the breast

Answer 8

• Anterior and lateral cutaneous branches of 3rd to 6th intercostal nerves
  o Convey sympathetic fibers to blood vessels and smooth muscles
• Nervous plexus around nipple helps signaling suckling

Question 9

List the nerves vulnerable during a masectomy

Answer 9

o Intercostal brachial n.
o Medial brachial cutaneous n.
o Long thoracic n.
o Thoracodorsal n.
o Medial pectoral n.

Question 10

What are the contents of the quadrangular space

Answer 10

axillary nerve
posterior circumflex humeral artery

Question 11

What are the contents of the triangular space

Answer 11

circumflex scapular artery

Question 12

What are the contents of the triangular interval

Answer 12

radial nerve and the profunda brachii vessels

Question 13

what are the superior, inferior, lateral and medial boundaries of the quadrangular space

Answer 13

• Superior: teres minor
• Inferior: teres major
• Lateral: surgical neck of humerus
• Medial: long head of triceps

Question 14

what are the superior, inferior and lateral boundaries of the triangular space

Answer 14

Boundaries
* Superior: teres minor
* Inferior: teres major
* Lateral: long head of triceps

Question 15

what are the superior, medial and lateral boundaries of the triangular interval

Answer 15

Boundaries
* Superior: subscapularis (anteriorly) and teres major (posteriorly)
* Medial: long head of triceps
* Lateral: humerus

Question 16

origin of the supraspinatus muscle

Answer 16

supraspinous fossa of the scapula

Question 17

origin of the infraspinatus muscle

Answer 17

infraspinous fossa of the scapula

Question 18

origin of the teres minor

Answer 18

middle part of the lateral border of the scapula

Question 19

origin of the subscapularis

Answer 19

subscapular fossa of the scapula

Question 20

insertion of the supraspinatus

Answer 20

superior facet of the greater tubercle of the humerus

Question 21

insertion of the infraspinatus

Answer 21

middle facet of the greater tubercle of the humerus

Question 22

insertion of the teres minor

Answer 22

inferior aspect of the greater tubercle of humerus

Question 23

insertion of subscapularis

Answer 23

lesser tubercle of humerus

Question 24

innervation of supraspinatus

Answer 24

suprascapular nerve

Question 25

innervation of the infraspinatus

Answer 25

suprascapular nerve

Question 26

innervation of the teres minor

Answer 26

axillary nerve

Question 27

innervation of the subscapularis

Answer 27

upper and lower subscapular nerve

Question 28

muscle action of supraspinatus

Answer 28

initiates & assists deltoid in abduction of humerus for first 15°

Question 29

muscle action of the infraspinatus

Answer 29

laterally rotates humerus

Question 30

muscle action of the teres minor

Answer 30

laterally rotates humerus

Question 31

muscle action of subscapularis

Answer 31

medially rotates humerus and helps hold head of humerus in glenoid cavity

Question 32

origin of deltoid muscle

Answer 32

 Clavicular part – lat. ⅓ of clavicle  Acromial part – acromion  Spinal part – scapular spine

Question 33

insertion of deltoid

Answer 33

deltoid tuberosity of humerus

Question 34

innervation of deltoid

Answer 34

axillary nerve

Question 35

muscle action of deltoid

Answer 35

 Acromial part – abduction of arm (assisted by supraspinatus for 1st 15°)  Clavicular part – flexes & medially rotates arm  Spinal part – extends & laterally rotates arm  Helps stabilize glenohumeral joint  Holds head of humerus in glenoid cavity

Question 36

blood supply of the glehumral joint

Answer 36

 Ant. & post. circumflex humeral aa.  Suprascapular a

Question 37

innervation of the glenohumral joint

Answer 37

* Nerve:  Suprascapular n.  Axillary n.  Lateral pectoral n

Question 38

origin of teres major

Answer 38

posterior surface of inferior angle of scapula

Question 39

insertion of teres major

Answer 39

medial lip of intertubercular sulcus of humerus

Question 40

innervation of teres major

Answer 40

lower subscapular nerve (C5,C6)

Question 41

Origin of levator scapulae

Answer 41

Posterior tubercles of transverse processes of C1- C4 vertebrae

Question 42

origin of rhomboid minor and major

Answer 42

Minor: * Nuchal ligament * Spinous processes of C7&T1 vertebrae Major: * Spinous processes of T2-T5 vertebrae

Question 43

insertion of levator scapula

Answer 43

Medial border of scapular superior to root of scapular spine

Question 44

insertion of rhomboid minor and major

Answer 44

Minor: * Smooth triangular area at medial end of scapular spine Major: * Medial border of scapula from level of spine to inferior angle

Question 45

innervation of levator scapula

Answer 45

* Dorsal scapular nerves (C4,C5) * Cervical nerves (C3,C4)

Question 46

innervation of rhomboid major and minor

Answer 46

Dorsal scapular nerve (C4,C5)

Question 47

muscle action of levator scapula

Answer 47

* Elevates scapula * Rotates glenoid cavity inferiorly

Question 48

muscle action of rhomboid minor and major

Answer 48

* Retract scapula and rotates glenoid cavity inferiorly * Fix scapula to thoracic wall

Question 49

origin of trapezius

Answer 49

Medial third of superior nuchal line * External occipital protuberance * nuchal ligament * Spinous processes of C7-T12 vertebrae

Question 50

origin of latissimus dorsi

Answer 50

* Spinous processes of inferior 6 thoracic vertebrae * Thoracolumbar fascia * Iliac crest * Inferior 3/4 ribs

Question 51

insertion of trapezius

Answer 51

* Lateral third of clavicle * Acromion and spine of scapula

Question 52

insertion of latissimus dorsi

Answer 52

Floor of the intertubercular sulcus of the humerus

Question 53

innervation of trapezius

Answer 53

* Spinal accessory nerve (CN XI) (motor fibres) * C3, C4 (pain and proprioceptive fibres)

Question 54

innervation of latissimus dorsi

Answer 54

Thoracodorsal nerve (C6,C7,C8)

Question 55

muscle action of trapezius

Answer 55

* Descending part elevates * Ascending part depresses * All parts retract scapula * Ascending and descending rotate glenoid cavity superiorly

Question 56

muscle action of latissimus dorsi

Answer 56

* Extends, adducts, medially rotates humerus * Raises the body towards arms during climbing

Question 57

what factors stabilize the glenohumeral joint

Answer 57

* Factors for stability: o Glenoid labrum- increases concavity o Coracoacromial arch- prevents upward dislocation o Tendon of long head of biceps- superior support o Long head of triceps- inferior support during abduction o Ligaments o Rotator cuff muscles- strong lateral stability, stabilizes head of humerus in glenoid cavity * Supraspinatus * Infraspinatus * Teres minor * Subscapularis