The Axila

Question 1

Pectoral Region

Answer 1

Clavicles, strenum, ribs, and scapula

Question 2

Parts of sternum

Answer 2

Manubrium, body, and xiphoid process (one of the last things to turn boney in your 20s)

Question 3

Types of ribs

Answer 3

Atypical: 1,2 = short, don’t have regular features, shaped funny, and don’t attach at sternum. 11 and 12 = floating, no anterior bone attachments.
True: vertebrocostal. 1-7. Have their own costal cartilage that goes from rib to sternum.
False: 8-10, don’t have own costocartilage attachments, piggyback onto others.

Question 4

Where are ribs located and where do they articulate

Answer 4

Location: thoracic region
Articulation: sternum and vertebrae

Question 5

Notches on manubrium

Answer 5

Clavicular notch and jugular notch/suprasternal notch.

Question 6

What is the manubrium sternal angle?

Answer 6

where the maubrium and the sternum meet. aka manubriosternal joint. Where second rib attaches.

Question 7

Where do the ribs articulate?

Answer 7

1 - manubrium
2- manubrium sternal angle
3-6 - body of sternum
7 - xiphoid process. 8-10 piggy back here.

Head of rib at vertebrae. Costal cartilage at sternum.

Question 8

What is the breast, what is it innervated by, where does it rest, where does it attach.

Answer 8

Cutaneous surface.
Modified sweat gland.
Rests on pectoral fascia above pectoralis major.
Retromammary space is potential space between breast and pectoral fascia.
Innervated by intercostal nerves 4-6. (Some supraclavicular nerve innervation.)
Attaches to dermis of overlying skin via suspensory ligaments (Cooper’s ligaments).
15-20 lactiferous ducts open at nipple.
Grow along mammary ridge.

Question 9

Structure of Breast

Answer 9

Mammary gland lobules –> alveolus –> lactiferous ducts –> lactiferous sinus –> nipple –> areola.

Question 10

Breast Arteries

Answer 10

Axillary and subclavian arteries = main supply of blood. Lateral thoracic and internal thoracic arteries. All go to mammary branches.

Question 11

Breast Venous Drainage

Answer 11

To axillary vein via lateral thoracic veins, medial mammary veins. Over 75% goes to axillary lymph nodes.

Question 12

Superficial Fascia

Answer 12

Consists of: platysma, supraclavicular nerves, anterior & lateral branches of intercostal nerves

Question 13

Deltopectoral (clavipectoral) triangle

Answer 13

Muscles: deltoid, pectorals major, middle 1/3 of clavicle makes border
Drainage: Cephalic vein and deltopectoral lymph nodes
Blood Supply: deltoid branch of thoracoacromial artery (branch of axillary artery)

Question 14

Clavipectoral fascia

Answer 14

Invests subclavius and pectoralis minor
Attaches to clavicle and anterior thoracic wall
Cephalic vein, thoracoacromial artery, and lateral pectoral nerves peirce it.
Becomes suspensory ligament of axilla.

Question 15

Muscles of pectoral region

Answer 15

Pectorals major, subclavius, pectorals minor, serratus anterior

Question 16

Attachments of pectoralis major

Answer 16

Proximal: anterior surface of medial 1/2 of clavicle and anterior surface of sternum and superior 6 costal cartilages.
Distal: Lateral lip of inter tubercular sulcus (bicipital groove)

Question 17

Actions of pectoralis major

Answer 17

adducts and medially rotates humerus.
draws scapula anteriorly+inferiorly (via clavicle)
Clavicular portion flexes humerus.
Sternal portion can extend humerus while it is in this fixed position.

Question 18

Blood supply and innervation for pectoralis major

Answer 18

Blood supply: pectoral branches of thoracoacromial arterial trunk.
Innervation: lateral and medial pectoral nerves. From lateral and medial cord of brachial plexus respectively, not named for anatomical position.

Question 19

Attachments of pectoralis minor

Answer 19

Proximal: 3rd-5th rib, near costal cartilage
Distal: coracoid process of scapula

Question 20

Actions of pectoralis minor

Answer 20

Stabilizes scapula by pulling it anteriorly & inferiorly against posterior thoracic wall

Question 21

Blood supply and innervation for pectoralis minor

Answer 21

Blood supply: pectoral branches of thoracoacromial arteries trunk.
Innervation: usually pierced by medial pectoral nerve.

Question 22

Attachments of subclavius

Answer 22

Proximal: junction of 1st rib and costal cartilage
Distal: inferior surface of middle 1/3 of clavicle

Question 23

Actions of subclavius

Answer 23

Anchors and depresses clavicle

Question 24

Blood supply and innervation for subclavius

Answer 24

Blood supply: clavicular branches of thoracoacromial arterial truck.
Innervation: nerve to subclavius

Question 25

Attachments of serrates anterior

Answer 25

Proximal: external surfaces of lateral parts of ribs 1-9
Distal: anterior surface of medial border of scapula

Question 26

Actions of serrates anterior

Answer 26

Protracts scapula, rotates scapula, holds scapula against thorax

Question 27

Blood supply and innervation for serrates anterior

Answer 27

Blood supply: lateral thoracic artery

Innervation: long thoracic nerve

Question 28

Arteries that contribute to pectoral, shoulder and axillary region

Answer 28

Subclavian and Axillary

Question 29

Where doe the subclavian artery become the axillary artery

Answer 29

At the lateral border of first rib

Question 30

Dorsal scapular artery can arise from ____ or _____

Answer 30

subclavian or transverse arteries

Question 31

Where doe the dorsal scapular artery run?

Answer 31

Along the vertebral border of the scapula

Question 32

Part 1 of axillary artery

Answer 32

superior thoracic artery

Question 33

Part 2 of axillary artery

Answer 33

Thoracoacromial trunk. 4 branches: pectoral, deltoid, acromial, clavicular.

Question 34

Part 3 of axillary artery

Answer 34

Subscapular artery: circumflex scapular and thoracodorsal. Anterior circumflex humeral
Posterior circumflex humeral
Lateral thoracic

Question 35

Venous drainage of axillary and pectoral region

Answer 35

Axillary vein

Question 36

Where does the axillary vein receive blood from?

Answer 36

Deep brachial veins
Superficial veins of the arm and forearm: basilic veins (continues as axillary vein) and cephalic vein (drains into axillary before becoming subclavian vein).

Question 37

Boundaries of axilla

Answer 37

pyramid shaped space
apex: clavicle, scapula, and 1st rib
base (A&P axillary folds): skin & superficial fascia, anterior axillary fold (pec. major), posterior axillary fold (latissimus dorsi and teres major), and chest wall (serrates anterior)
anterior wall: pec. major and minor. (clavicle and subclavius)
posterior wall: scapula, subscapularis, latissimus dorsi, and teres major
medial wall
lateral wall: intertubercular sulcus (bicipital groove), tendon of long head of biceps, coracobrachialis tendon.