Pectoral and Axillary Regions

Question 1

Pectoral Region Osteology

Answer 1

Clavicles
Sternum
Ribs
Scapula

Question 2

Ribs

Answer 2

Thoracic Region
Articulate w/ sternum and vertebrae
Ribs 1, 2, 11 & 12 (atypical)
Ribs 1-7: true
Ribs 8-10: False
Ribs 11 & 12 Floating

Question 3

Sternum

Answer 3

manubrium
body
xiphoid

Question 4

Breasts

Answer 4

Glandular Structures in males and females
More developed in females
Modified sweat glands
Rest on pectoral fascia
Retromammary: between breast and pectoral fascia
Innervated by intercostal nerves 4th-6th

Question 5

Breast: Continued

Answer 5

attaches to dermis via suspensory (Cooper’s) ligaments
gland lobules converge on nipple
15-20 lactiferous ducts open at nipple: surrounded by pigmented areola

Question 6

Arterial Supply of Breast Tissue

Answer 6

Mammary Branches from anterior intercostal
lateral thoracic
internal thoracic arterties

Question 7

Venous Drainage of Breast

Answer 7

Mainly to axillary vein via lateral thoracic vein and medial mammary veins

some drainage to internal thoracic vein via anterior intercostal veins

Question 8

Lymphatic Drainage of Breast

Answer 8

Nipple, areola, lac. lobules: drain to subareolar lymph nodes

75% of lymph from breast: axillary lymph nodes

Remaining: parasternal and abdominal lymph nodes

Question 9

Polymastia and Polythelia

Answer 9

Supernumerary Breasts or Nipples

Question 10

Superficial Fascia of Pectoral Region

Answer 10

Platysma
Supraclavicular nerves
Anterior and Lateral Branches of intercostal nerves

Question 11

Deltopectoral (clavipectoral) Triangle

Answer 11

Deltoid
Pectoralis major
middle 1/3 of clavice (all borders)

Cephalic vein
Deltopectoral lymph nodes
Deltoid branch of Thoracoarcomial artery

Question 12

Clavipectoral Fascia

Answer 12

Invests subclavius and pectoralis minor

Attaches to clavicle and anterior thoracic wall

Cephalic vein
thoracoacromial artery
pectoral nerves (all pierce it)

becomes suspensory ligament of axilla

Question 13

Pectoralis Major Muscle

Answer 13

Origin: ant. surface of medial 1/2 clavicle
ant. surface of sternum and sup. 6 costal cartilages

Insertion: lateral lip of intertubercular sulcus

Axns: adducts humerus
medial rotates humerus
draws scapular anteriorly & inferiorly (via clavicle)
flexes humerus
also extends humerus (sternal portion)

Blood: pectoral branches of thoracoacromial arterial trunk

Nerve: lateral and medial pectoralis nerves: C5-8, T1 sternocostal portion

Question 14

Pectoralis Minor

Answer 14

Origin: 3rd-5th ribs
Insertion: coracoid process  of scapula
Axns: stabilize scapula
Blood: same as pec major
Nerve: medial pectoral nerve (C8, T1)
*usually pierced by its nerve)

Question 15

Subclavius

Answer 15

Origin: jxn of 1st rib and its cartilage
Insertion: inf. surface of middle 1/3 clavicle
Axns: anchors & depresses clavicle
Blood: clavicular branch of thoracoacromial arterial trunk
Nerve: nerve to subclavius (C5-6)

Question 16

Pectoral Region Blood Supply

Answer 16

Axillary Artery

Question 17

Axillary Artery: Pec. minor divides it into 3 portions

Answer 17

Part 1: prox./medi. to P.minor
superior thoracic artery

Part 2: at or behind P minor
Thoracoacromial trunk:
pectoral branch
deltoid branch
acromial branch
clavicular branch

Part 3: distal/lateral to P minor
Subscapular artery: circumflex scapular and thor.dors.
Ant. circumflex humeral
Post. circumflex humeral

Question 18

Venous Drainage of Pectoral Region

Answer 18

Axillary Vein:

Deep Brachial Vein

Superficial Veins of arm and forearm
basilic veins and cephalic veins

Question 19

Boundaries of Axilla:

Answer 19

slide 34 picture

Question 20

Axillary Sheath

Answer 20

Axillary Vein
Axillary Artery
Brachial Plexus