Back, Pectoral Region, Breast and Axilla Flashcards

1
Q

[4-minute video]: the Axillary Artery

A

📝

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2
Q

[38-minute video]: the mighty Brachial Plexus

A

😎

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3
Q

Describe the origin and insertion of pectoralis major.

A

Origin:
Clavicular head: anterior surface of the medial half of the clavicle
Sternocostal head:
(a) lateral half of the anterior surface of the sternum, up to the 6th costal cartilage
(b) medial parts of 2nd-6th costal cartilages
(c) aponeurosis of the external oblique muscle of the abdomen

Insertion: Lateral lip of intertubercular sulcus

[Diagram]

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4
Q

What are the actions of pectoralis major at the shoulder joint and scapulothoracic joint?

A

Shoulder joint: arm adduction (sternocostal head), arm internal rotation, arm flexion (clavicular head), extension of flexed arm (sternocostal head)

Scapulothoracic joint: contributes to protraction of the scapula [alt: draws the scapula anteroinferiorly]

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5
Q

What is the anatomical basis of Poland syndrome?

A

This is an embryonic malformation of the thoracic wall, which is accompanied by a defect on the pectoralis major in combination with other malformations of the upper extremities such as malformation of the fingers. The muscle can be partly or completely missing.

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6
Q

Using landmarks of the bone, explain how you would side a clavicle.

A

The conoid tubercle is posterolateral.
The groove for subclavius muscle is inferior.
The impression for the costoclavicular ligament is inferomedial.
Viewing the bone anteriorly, the medial two thirds is convex, whereas the lateral one third is concave.

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7
Q

What muscle that covers the shoulder is commonly used for intramuscular injections?

A

Deltoid muscle

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8
Q

Which ligament attaches clavicle to scapula?

A

Coracoclavicular ligament

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9
Q

Which ligament anchors clavicle to the first costal cartilage?

A

Costoclavicular ligament

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10
Q

Name the parts of the clavicle as you appreciate with an atlas or/and the bone itself. (Approximately 8)

A
  1. Acromial end and acromial facet
  2. Sternal end and Sternal facet
  3. Anterior and posterior sides
  4. Conoid tubercle for attachment of conoid part (conoid ligament) of coracoclavicular ligament
  5. Trapezoid line for attachment of trapezoid part (trapezoid ligament) of coracoclavicular ligament
  6. Subclavian groove for attachment of subclavian muscle
  7. Impression for costoclavicular ligament
  8. Nutrient foramen
  9. [Diagram 1] [Diagram 2]
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11
Q

State the functions of the clavicle. (3)

A
  1. It acts as a strut for holding the upper limb far from the trunk so it can move freely.
  2. It transmits forces from the upper limb to the axial skeleton (sternum).
  3. It provides an area for the attachment of muscles.
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12
Q

Appreciate peculiarities of the clavicle. (7)

A
  1. only long bone that lies horizontally
  2. no medullary cavity (the medullary cavity is the hollow part of bone that contains bone marrow)
  3. subcutaneous throughout its extent
  4. first bone to start ossifying (between the 5th and 6th week of intrauterine life) and last bone to complete its ossification (at 25 years)
  5. only long bone which ossifies by two primary centers [Diagram]
  6. only long bone which ossifies via intramembranous ossification except for its medial end
  7. may be pierced through and through by cutaneous nerve (intermediate supraclavicular nerve)
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13
Q

State the position of the nutrient artery in the clavicle and indicate its importance.

A

The nutrient foramen is mostly located closer to the sternal end of the clavicle (posterior, middle 1/3). Especially during osteosynthesis of clavicle fractures at the sternal end, maintaining the arterial supply of the clavicle is of great importance for increasing the post-operative life quality of patients.
[Image: nutrient artery of clavicle]

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14
Q

What is the importance of the sternum in clinical practice?

A

The sternum is a crucial anatomical landmark in clinical practice for a number of procedures, including central venous catheterization, bone marrow biopsy, and chest compressions during cardiopulmonary resuscitation (CPR). It is also a common site for fractures, which can occur due to blunt trauma to the chest.

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15
Q

State the origin and insertion of pectoralis minor.

A

Origin: it arises from the 3rd, 4th and 5th ribs, near their costal cartilages
Insertion: medial border and upper surface of the coracoid process
[Diagram]

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16
Q

State the nerve supply of pectoralis minor. (and root values too)

A

medial pectoral nerve
(C8, T1)

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17
Q

State 4 actions of pectoralis minor.

A
  1. It assists serratus anterior in drawing the scapula forward (protraction) for punching action.
  2. Depresses the scapula together with serratus anterior
  3. Acts as an accessory muscle of respiration during forced inspiration
  4. Aids in medial or downward rotation of scapula (inferior angle of scapula moves medially; pectoralis minor exerts force on the coracoid process, which pulls the lateral aspect of the scapula inferiorly)

Its subsequent contraction assists gravity in restoring the scapula to the rest position.

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18
Q

The sternal angle is an important landmark in the chest. Elaborate.

A
  1. It marks the point at which the costal cartilage of the second rib articulate with the sternum (second sternocostal/sternochondral joint). This is particularly useful when counting ribs to identify landmarks, as rib one is often impalpable.
  2. It is also used to identify the boundary between the superior and inferior mediastinal cavities.
  3. It is at the level of the intervertebral disc between thoracic vertebrae 4 and 5.
  4. This is the superior extent of the heart as well as the inferior end of the trachea when a person is supine.
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19
Q

The clavicle is the most commonly fractured bone in the body. Explain.

Points of reference:
1. Which point is most prone to fractures?
2. What are likely situations that would result in such a fracture?
3. How are the lateral and medial parts of the clavicle likely to be displaced by the muscles attached to them?
4. What would be the clinical presentation of a fractured clavicle?
5. What are three reasons for fracture of the clavicle at the specific point mentioned in number 1?

A

It commonly fractures at the junction of its lateral one-third and medial two-third due to blows to the shoulder or indirect forces, usually as a result of strong impact on the hand or shoulder, when person falls on the outstretched hand or the shoulder. [X-ray image] [Image: clinical presentation]

When fracture occurs, the lateral fragment is displaced downward by the weight of the upper limb because trapezius alone is unable to support the weight of the upper limb. In addition, the lateral fragment is drawn medially by shoulder adductors viz. teres major, etc. The medial fragment is slightly elevated by the sternocleidomastoid muscle.

The characteristic clinical picture of the patient with a fractured clavicle is that of a man/woman supporting his sagging upper limb with the opposite hand.

The fracture at the junction of lateral one third and medial two-third occurs because:
(a) This is the weakest site.
(b) Two curvatures of clavicle meet at this site.
(c) The transmission of forces (due to impact) from the clavicle to scapula occur at this site through coracoclavicular ligament.

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20
Q

State the origin and insertion of subclavius.

A

Origin: It arises from the first rib at the costochondral junction.
Insertion: It is inserted into the subclavian groove on the inferior surface of the clavicle.

[Diagram: Subclavius]

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21
Q

State the root values of nerve to subclavius.

A

C5, C6

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22
Q

State the action of subclavius.

A

~ It depresses the clavicle.
~ It stabilizes the sternoclavicular joint.

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23
Q

Describe the origin and insertion of serratus anterior.

A

Origin: it arises by a series of 8 digitations from the upper 8 ribs. The first digitation arises from the first and second ribs.
Insertion: It is inserted into the costal surface of the scapula along its medial border. (The first 2 digitations are inserted into the superior angle, next 2 digitations into the medial border and the lower 4 or 5 digitations into the inferior angle of the scapula.)
[Diagram: serratus anterior]

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24
Q

What are the cutaneous nerves of the pectoral region?

A

~ Supraclavicular nerves (medial, intermediate, and lateral) - supply skin on the front of chest to a horizontal line at the sternal angle
~ Lateral cutaneous branches of intercostal nerves (T3, T4, T5, T6) and anterior cutaneous branches of intercostal nerve (T2, T3, T4, T5, T6)
[Diagram]

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25
Q

Pain arising from the diaphragm can be felt over the shoulder region. Account for this fact.

A

Referred pain. The diaphragm is innervated by the phrenic nerve, which originates from the cervical spinal cord. The phrenic nerve also provides sensory innervation to the shoulder region. Therefore, when the diaphragm is irritated or inflamed, the pain signals are transmitted to the spinal cord and interpreted as pain in the shoulder.

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26
Q

State the nerve that supplies serratus anterior and state its root values.

A

Long thoracic nerve to serratus anterior (C5, 6, 7).

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27
Q

State three actions of serratus anterior.

A
  1. It is a powerful protractor of the scapula (it pulls the scapula forward around the chest wall for pushing and punching movements as required during boxing. Hence, serratus anterior is also called boxer’s muscle.)
  2. It keeps the medial/vertebral border of scapula in firm contact with the chest wall.
  3. Its lower 4 or 5 digitations along with lower part of the trapezius** rotate the scapula laterally and upwards** during overhead abduction of the arm.
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28
Q

State the clinical relevance of the subclavius muscle.

A

It may prevent the jagged ends of a fractured clavicle from damaging the adjacent subclavian vein.

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29
Q

What structures pierce the clavipectoral fascia?

A
  1. Cephalic vein
  2. Lateral pectoral nerve
  3. Thoraco-acromial artery
  4. Lymphatic vessels passing between infraclavicular and apical nodes of axilla
  5. [Diagram]
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30
Q

The spinal nerves between the 4th cervical and 1st thoracic segments do not give cutaneous supply to the skin of the anterior thoracic wall. Account for this fact.

A

The lower cervical and first thoracic anterior rami form the brachial plexus, which supplies the upper limb. The cutaneous supply to the skin of the anterior thoracic wall is provided by the intercostal nerves, which are derived from the thoracic spinal nerves.

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31
Q

State two signs of paralysis of serratus anterior.

A

(a) Weakened protraction of the scapula.
(b) Winging of the scapula (Inferior angle and medial border of scapula become unduly prominent particularly when patient pushes his hands against the wall).

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32
Q

Medial scapular winging is caused by injury to the ____(a)____ nerve and hence paralysis of ____(b)____ muscle. Lateral scapular winging is caused by injury to the ____(c)____ nerve and hence paralysis of ____(d)____ muscle.
Medial scapular winging is worsened by arm ____(e)____, whereas lateral scapular winging is worsened by arm ____(f)____.

A

(a) long thoracic (C5, C6, C7)
(b) serratus anterior
(c) spinal accessory
(d) trapezius
(e) flexion
(f) abduction
[8-minute video]

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33
Q

Describe the origin and insertion of deltoid muscle.

A

Origin:
1. Anterior unipennate part: upper surface and anterior border of lateral third of clavicle
2. Middle multipennate part: lateral border of acromion
3. Posterior unipennate part: lower lip of crest of spine of scapula

Insertion: V-shaped deltoid tuberosity on lateral aspect of midshaft of humerus

[Diagram: deltoid]

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34
Q

State the nerve supply of deltoid muscle.

A

Axillary nerve (C5, 6)

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35
Q

Describe the actions of deltoid.

A
  1. Anterior (clavicular) fibres are flexors and medial rotators of the arm.
  2. The posterior (spinous) fibres are the extensors and lateral rotators of the arm.
  3. The lateral (acromial) fibres are strong abductors of the arm from 15-90 degrees.
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36
Q

Why can’t the acromial fibres of the deltoid abduct the arm from 0-15 degrees?

A

Within this range, their vertical pull corresponds to the long axis of the arm.

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37
Q

Describe origin and insertion of supraspinatus.

A

Origin: medial 2/3 of supraspinous fossa of scapula
Insertion: superior facet on greater tubercle of the humerus
[Diagram: supraspinatus]

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38
Q

State the innervation of supraspinatus (+ root values).

A

suprascapular nerve (C5, C6)

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39
Q

State the actions of supraspinatus.

A

Supraspinatus initiates the abduction of shoulder. It is responsible for first 15° of abduction of the shoulder and thus assists the deltoid in carrying abduction thereafter, i.e. from 15° to 90°.

40
Q

Describe the origin and insertion of infraspinatus.

A

Origin: medial two thirds of the infraspinous fossa
Insertion: middle facet of greater tubercle of humerus

[Diagram] [Cadaveric image 1] [Cadaveric image 2]

41
Q

State the innervation of infraspinatus (+ root values).

A

suprascapular nerve (C5, 6)

42
Q

State the action of infraspinatus.

A

lateral rotator of humerus
[Diagram]: medial and lateral rotation of the humerus

43
Q

Describe the origin and insertion of teres minor.

A

Origin: posterior aspect of the lateral border of the scapula
Insertion: lower facet of greater tubercle of humerus

44
Q

State the innervation of teres minor.

A

nerve to teres minor (a branch of axillary nerve) (C5, 6)

45
Q

State the actions of teres minor.

A

It is a lateral rotator and weak adductor of the humerus.

46
Q

Describe the origin and insertion of teres major.

A

Origin: oval area on dorsal surface of inferior angle of scapula
Insertion: medial lip of the intertubercular sulcus
[Diagram 1] [Diagram 2] [Cadaveric image]

47
Q

State the nerve supply of teres major.

A

lower subscapular nerve (C5, 6, 7)

48
Q

State the action of teres major.

A

medial rotator of the humerus
[Diagram]: medial and lateral rotation of the humerus

49
Q

Describe the origin and insertion of subscapularis.

A

Origin:
(a) medial 2/3 of the costal surface of the scapula
(b) tendinous intermuscular septa attached to the ridges on the bone
Insertion: lesser tubercle of the humerus
[Diagram]

50
Q

State the nerve supply of subscapularis.

A

upper and lower subscapular nerves (C5, C6)

51
Q

State the actions of subscapularis.

A

medial rotator of humerus

52
Q

Name four muscles that stabilize the head of the humerus in the glenoid fossa during shoulder movements.

A
  1. supraspinatus
  2. infraspinatus
  3. teres minor
  4. subscapularis
53
Q

What is the rotator cuff?

A

These are the tendons of supraspinatus, infraspinatus, teres minor and subscapularis which are fused with the underlying capsule of the glenohumeral joint.

54
Q

What are two components of the coracoclavicular ligament?

A
  1. Trapezoid ligament
  2. Conoid ligament
  3. [Diagram]
55
Q

Describe the origin of trapezius. (5 points of origin)

A

(a) medial third of the superior nuchal line
(b) the external occipital protuberance
(c) ligamentum nuchae
(d) spine of 7th cervical vertebra
(e) spines of all thoracic vertebrae
(f) [Diagram: Trapezius]

Further notes:
The ligamentum nuchae is a midline intervertebral syndesmosis that spans the cervical spine, and its posterior border is firmly attached to the external occipital protuberance (superiorly) and to the spinous process of C7 (inferiorly).

56
Q

Describe the insertion of trapezius.

A
  1. Superior fibres: posterior border of lateral third of clavicle
  2. Middle fibres: medial margin of acromion
  3. Lower fibres: superior margin of spine of scapula
57
Q

Describe the innervation of trapezius.

A
  1. Spinal part of the accessory nerve (provides motor supply) [CN XI]
  2. Ventral rami of C3 and C4 (proprioceptive sensations)
58
Q

State the actions of trapezius. (4)

A
  1. The upper fibres of trapezius along with levator scapulae elevate the scapula as in shrugging the shoulder.
  2. The middle fibres of trapezius along with rhomboids retract the scapula as in bracing back the shoulder.
  3. The lower fibres of trapezius depress the medial part of the spine of the scapula.
  4. Acting with serratus anterior, the trapezius rotates the scapula upward so that the arm can be abducted beyond 90°.
  5. [Diagram: fibre groups of trapezius]
59
Q

Describe the origin and insertion of latissimus dorsi. (Hint: 5 points of origin)

A

Origin:
(1) spines of lower six thoracic vertebrae anterior to the trapezius, by tendinous fibres
(2) posterior lamina of thoraco-lumbar fascia (by which it is attached to the spines of lumbar and sacral vertebrae) by tendinous fibres
(3) outer lip of the posterior part of the iliac crest by muscular slips
(4) lower three or four ribs by fleshy slips
(5) inferior angle of the scapula

Insertion: floor of the intertubercular sulcus

60
Q

State the innervation of latissimus dorsi.

A

thoracodorsal nerve (C6-8) from posterior cord of brachial plexus

61
Q

State the actions of latissimus dorsi.

A
  1. Adduction of humerus
  2. Medial rotation of the humerus
  3. Extension from flexed position
  4. Downward rotation of the scapula
  5. Pulls up the trunk upwards and forward during climbing
62
Q

Name three arteries that supply the breast.

A
  1. Perforating branches of internal thoracic artery (mammary artery) - supply breast medially
  2. Perforating branches of posterior intercostal arteries - supply breast medially
  3. Axillary artery - lateral thoracic artery supplies breast laterally [superior thoracic and thoracoacromial branches also supply the breast]
63
Q

Name three branches of the axillary artery that supply the breast. (From medial to lateral)

A
  1. Supreme/superior thoracic artery
  2. Acromio-thoracic artery
  3. Lateral thoracic artery
64
Q

Outline the important surface landmarks of the back.

A
  1. Scapula (most important one)
  2. 8th and 12th ribs
  3. Iliac crest, Sacrum, Coccyx
  4. Spines of vertebra
  5. External occipital protuberance and superior nuchal lines, nuchal groove furrow, ligamentum nuchae
65
Q

The muscles attaching scapula to the back of the trunk (posterior axio-appendicular muscles) are arranged in 2 layers. Name the two layers and the muscles that comprise each.

A

Superficial layer:
Trapezius
Latissimus dorsi

Deep layer:
Levator scapulae
Rhomboideus major
Rhomboideus minor

66
Q

State the origin of levator scapulae.

A

Simply put: transverse processes of C1, C2, C3 and C4. But for specificity,

  1. Transverse processes of atlas and axis vertebrae
  2. Posterior tubercles of transverse processes of C3 and C4 vertebrae.
  3. [Diagram]
67
Q

State the insertion of levator scapulae.

A

medial border of scapula from superior angle to root of spine of scapula
[Diagram]

68
Q

levator scapulae innervation

A
  • nerves off cervical plexus (direct branches), C3, C4
  • dorsal scapular nerve, C5
69
Q

State the actions of levator scapulae.

A
  1. Elevates and steadies the scapula during arm movements
  2. Extends and/or laterally flexes the head (this particular action will be appreciated later)
70
Q

State the origin and insertion of rhomboideus major.

A

Origin: spine of T2-T5 vertebra, intervening supraspinous ligament

Insertion: medial border of scapula between scapular spine and inferior angle of scapula

71
Q

State the origin and insertion of rhomboideus minor.

A

Origin: Lower part of ligamentum nuchae and spines of C7 and T1 vertebrae
Insertion: Base of triangular area at the root of the scapular spine

72
Q

State the innervation and actions of Rhomboideus major and minor.

A

a) Innervation: Dorsal scapular nerve (C5)
b) Actions: retract scapula, elevates scapula
NB: Rhomboideus major also medially rotates scapula in addition to the above mentioned actions.

73
Q

Mention the movements of the scapula and the muscles involved.

A
  1. Elevation - superior fibres of trapezius, levator scapulae
  2. Depression - lower fibres of pectoralis major, latissimus dorsi, pectoralis minor
  3. Protraction - serratus anterior, pectoralis minor
  4. Retraction - middle fibres of trapezius, the two rhomboids
  5. Medial rotation - levator scapulae, rhomboid major, weight of the upper limb
  6. Lateral rotation (during shoulder abduction)- upper and lower fibres of trapezius, lower part of serratus anterior
74
Q

What arteries contribute to the scapular anastomosis?

A

Suprascapular (from subclavian artery)

Transverse cervical (from thyrocervical trunk)

Circumflex scapular (from subscapular of 3rd part of axillary)

Thoracodorsal (from subscapular of 3rd part of axillary)

Posterior intercostal

75
Q

What are the functions of the scapular anastomosis?

A
  1. Ensure adequate arterial supply to the middle scapula
  2. Form a subsidiary route through which blood can pass from the proximal part of the subclavian artery to the third part of the axillary artery when either subclavian or axillary artery is blocked between these two points
  3. [Diagram: scapular anastomosis]
76
Q

State the boundaries, contents and clinical relevance of the quadrangular space.

A

(a) Boundaries
Medially: Long head of triceps
Laterally: Humeral shaft
Superiorly: Teres minor
Inferiorly: Teres major

(b) Contents
✓ Axillary nerve: It passes through this space on its path to innervate the teres minor and deltoid muscles and provide sensation to the lateral arm.
✓ Posterior circumflex humeral artery

(c) Clinical Relevance
The quadrangular space is a clinically important anatomical space in the arm as it provides the anterior regions of the axilla a passageway to the posterior regions. The axillary nerve and posterior humeral circumflex artery are at risk of injury in this space, which can lead to deltoid and teres minor muscle weakness, as well as sensory loss in the lateral arm.

77
Q

State the boundaries, contents, and clinical relevance of the upper triangular space.

A

(a) Boundaries
Superiorly: Lower border of the teres minor
Laterally: Long head of the triceps
Inferiorly: Teres major

(b) Contents
Circumflex scapular artery

(c) Clinical Relevance
The circumflex scapular artery is at risk of injury in this space, which can lead to ischemia of the deltoid muscle.

78
Q

State the boundaries, contents, and clinical relevance of the lower triangular space/triangular interval/triceps hiatus.

A

(a) Boundaries
Superior: Inferior border of the teres major.
Lateral: Shaft of the humerus and lateral head of the triceps brachii.
Medial: Lateral border of the long head of the triceps brachii.

(b) Contents
Radial nerve: It passes through this space on its way to the posterior compartment of the arm.
Profunda brachii artery: It also passes through this space from anterior to posterior.

(c) Clinical Relevance
The radial nerve and profunda brachii artery are at risk of injury in this space, which can lead to radial nerve palsy and ischemia of the posterior compartment of the arm. Triangular interval syndrome refers to compression of the radial nerve as it passes through the triangular interval. It is thought to occur secondary to hypertrophy of triceps brachii or teres major.

79
Q

Name two nerves that branch off from the upper trunk of the brachial plexus and state their root values and the muscles they innervate.

A
  1. nerve to subclavius (C5, C6) innervates subclavius
  2. suprascapular nerve (C5, C6) innervates supraspinatus and infraspinatus
80
Q

Name two nerves that branch off the roots of the brachial plexus and state their root values and the muscles they innervate.

A
  1. Long thoracic nerve (C5, C6, C7) innervates serratus anterior
  2. Dorsal scapular nerve (C5) innervates levator scapulae, rhomboid major, rhomboid minor
81
Q

Name three nerves that branch off the posterior cord of the brachial plexus and state their root values and the muscles they innervate. [not terminal branches]

A
  1. Upper subscapular nerve (C5, 6) innervates subscapularis
  2. Thoracodorsal nerve (some say middle subscapular nerve but thoracodorsal nerve is more preferred) (C6, C7, C8) innervates latissimus dorsi
  3. Lower subscapular nerve (C5, 6) innervates the subscapularis and teres major
82
Q

Name three nerves that branch off the medial cord of the brachial plexus and state their root values and the structures they innervate. [not terminal branches]

A
  1. medial pectoral nerve (C8, T1) innervates pectoralis major and pectoralis minor
  2. medial brachial cutaneous nerve (T1) supplies the skin of the posteromedial portion of the forearm
  3. medial antebrachial cutaneous nerve (C8, T1) supplies the skin of the anteromedial forearm
83
Q

Name the nerve that branches off the lateral cord of the brachial plexus and state its root value and the structure it innervates. [not terminal branches]

A

Lateral pectoral nerve (C5, C6, C7) supplies pectoralis major

84
Q

The breast develops from an ectodermal thickening called ___________.

A

milk line/ridge (of Schultz)

85
Q

Name the muscles involved in protraction (2) and retraction of the scapula (3).

A

Protraction: serratus anterior and pectoralis minor
Retraction: rhomboideus minor, rhomboideus major, middle fibres of trapezius

86
Q

Name the muscles involved in elevation (2) and depression (3) of the scapula.

A

Elevation: levator scapulae, upper fibres of trapezius
Depression: lower fibres of trapezius, latissimus dorsi, pectoralis minor (and the weight of the limb)

87
Q

Name the muscles involved in medial rotation (3) and lateral rotation (3) of the scapula.

A

Medial rotation: levator scapulae, rhomboideus minor and rhomboideus major
Lateral rotation: upper fibres of trapezius, lower fibres of trapezius, lower 5 digitations of serratus anterior

88
Q

Name the arteries that contribute to the scapular anastomosis. (Bonus: state their origins)

A

Around the body of the scapula
(1) deep branch of the transverse cervical artery (from thyrocervical trunk)
(2) suprascapular artery (from thyrocervical trunk)
(3) circumflex scapular artery (from subscapular artery, which in turn arises from the third part of the axillary artery)

Around the acromial process
(1) acromial branch of the thoracoacromial artery (thoracoacromial artery branches off from the 2nd part of the axillary artery)
(2) acromial branch of the posterior circumflex humeral artery (posterior circumflex humeral artery arises from the third part of the axillary artery)
(3) acromial branch of the suprascapular artery (the suprascapular artery arises from the thyrocervical trunk)

89
Q

Name the ligament that converts the suprascapular notch into the suprascapular canal.

A

superior transverse scapular ligament/suprascapular ligament

90
Q

State the extents of the breast.

A
  1. Vertically: it extends from the 2nd rib to the 6th rib
  2. Horizontally: it extends from the lateral border of the sternum to the midaxillary line
91
Q

Describe the sensory innervation of the breast.

A

a) anterior and lateral cutaneous branches of 2nd to 6th intercostal nerves
b) nipple is innervated by 4th intercostal nerve

92
Q

[3-minute video]: Lymphatic Drainage of the Breast

A

📚

93
Q

“Some lymph vessels from the inferomedial quadrant of the breast communicate with the ____(1)____ and carry cancer cells to it. From here cancer cells migrate transcoelomically and deposit on the ovary, producing a secondary tumor in the ovary called ____(2)____.

A
  1. subperitoneal lymph plexus
  2. Krukenberg’s tumor
94
Q

How does breast cancer present clinically?

A
  1. presence of a painless hard lump
  2. breast becomes fixed and immobile (due to infiltration of suspensory ligaments)
  3. retraction of skin (due to infiltration of suspensory ligaments)
  4. retraction of nipple (due to infiltration and fibrosis of lactiferous ducts)
  5. peau d’orange appearance of the skin (obstruction of superficial lymphatics)
95
Q

State the boundaries and clinical relevance of the triangle of auscultation.

A

[Diagram: Triangle of Auscultation]

Boundaries
☑ superior horizontal border of latissimus dorsi
☑ medial border of scapula
☑ inferolateral border of trapezius
☑ the floor is formed by 6th and 7th ribs and the 6th intercostal space

Clinical relevance
The upper part of the lower lobe of the lung lies deep to this triangle. When the scapulae are drawn anteriorly by folding the arm across the chest and trunk is flexed, this triangle enlarges and becomes more subcutaneous. Now the lower lobe of the lung can be auscultated by putting the stethoscope in this region. The sounds are not muffled by the muscles of the back in this area.