Pectoral Region and Axilla

Question 1

What joint is the upper extremity’s only bony connection to the body?

Answer 1

The sternoclavicular joint

Question 2

The clavicle is a strut that _________ the scapula and the rest of the upper limb, keeping the upper limb at a more functional distance from the body.

Answer 2

suspends

Question 3

To what is the subclavian artery renamed after it passes the first rib and descends into the axilla?

Answer 3

The axillary artery

Question 4

As the axillary artery descends the arm past the teres major, what is it renamed to?

Answer 4

The brachial artery

Question 5

What happens to the brachial artery in the forearm?

Answer 5

It divides into the radial and ulnar arteries, both of which end in the palm of the hand by forming the palmar arches.

Question 6

Describe the three segments of the axillary artery and its branches in each segment.

Answer 6

Proximal (1st) segment: Found proximal to the border of the pectoralis minor muscle. Has one branch - the supreme/superior thoracic artery.

Deep (2nd) segment: Found deep to the body of the pectoralis minor muscle. Has two branches - the thoracoacromial artery and the lateral thoracic artery.

Distal (3rd) segment: Found distal to the border of the pectoralis minor muscle and has three branches - the subscapular artery, the anterior humeral circumflex artery, and the posterior humeral circumflex artery.

Question 7

In which quadrant of the breast does cancer occur in 60% of breast cancer cases?

Answer 7

Upper lateral

Question 8

The upper limb is innervated by the nerve fibers of the ______ ______, which is formed from the ventral primary rami of spinal nerves _____, ______, _____, _____, and _____.

Answer 8

brachial plexus, C5, C6, C7, C8, T1

Question 9

Nerves from the brachial plexus can be categorized as either preaxial or postaxial nerves. The preaxial nerves supply muscles that act to ________, while the postaxial nerves supply muscles that act to _________.

Answer 9

preaxial nerves supply muscles that flex

postaxial nerves supply muscles that extend

Question 10

Given that preaxial nerves supply muscles that flex, these muscles are located on the ________ side of the limb and the postaxial nerves supplying muscles that extend are located on the _________ side of the limb.

Answer 10

preaxial (flex) - anterior limb

postaxial (extend) - posterior limb

Question 11

The cords of the brachial plexus are named according to the position with respect to the ________ _______.

Answer 11

axillary artery

Question 12

What is the basic organization of the brachial plexus?

Answer 12

5 ventral rami roots coalesce into 3 trunks (superior, middle, inferior), which divide and come back together to form 3 cords (lateral, posterior, medial), which divide to form 5 terminal branches.

Question 13

Winging of the scapula may occur due to paralysis of the ________ ________ muscle, which is innervated by the _______ _______ nerve.

Answer 13

paralysis of the serratus anterior muscle which is innervated by the long thoracic nerve.

Question 14

Describe the three types of shoulder separations.

Answer 14

Type 1: Incomplete tears of the acromioclavicular or coracoclavicular ligaments.
Type 2: Complete tear of acromioclavicular ligaments but NOT the coracoclavicular ligaments.
Type 3: All ligaments completely torn.

Question 15

Lymph from the lower lateral quadrant of the breast drains into the ________ lymph nodes.

Answer 15

pectoral

Question 16

Lymph from the upper medial quadrant of the breast drains into the ________ lymph nodes.

Answer 16

upper parasternal

Question 17

Lymph from the lower medial quadrant of the breast drains into the _________ and ________ lymph nodes.

Answer 17

lower parasternal and opposite parasternal nodes (at the other breast)

Question 18

Roots of the brachial plexus are both motor and sensory, while spinal nerve roots are either ______ or _______.

Answer 18

motor (ventral) or sensory (dorsal)

Question 19

The long thoracic nerve passes _________ (superficially or deep) to the serratus anterior.

Answer 19

superfically

Question 20

The median ______ vein is often a site for venous puncture in order to obtain a sample of blood or to administer medication.

Answer 20

median cubital vein

Question 21

Which three veins are most often used for central venous line catheterization?

Answer 21

1. Axillary vein
2. Subclavian vein
3. Internal jugular vein

Question 22

Radical masectomy includes removal of the breast and all its related structures, while a modified radical masectomy spares two muscles. Which muscles are they?

Answer 22

Pectoralis major and minor

Question 23

What is the axillary tail/process? Why is it clinically relevant?

Answer 23

It is the mammary tissue that extends laterally into the axilla. Important in breast exams.

Question 24

The breast is attached to the deep fascia by ___________ ligaments.

Answer 24

suspensory/Cooper’s ligaments

Question 25

The __________ space is a potential space covering the pectoralis major below the breast. It allows for movement of the breast upon the pectoralis major and is a common route for __________ to the pectoralis major.

Answer 25

retromammary space

common route for metastasis

Question 26

Which nerves provide sensory innervation to the breast area?

What dermatome covers the nipple?

Answer 26

Anterior and lateral cutaneous branches of the 2nd-6th intercostal nerves.

The nipple is in the T4 dermatome in both sexes.

Question 27

The _______ _______ duct drains the right side of the thorax and right side of the head and neck, while the _______ duct collects lymph from the rest of the body.

Answer 27

right lymphatic duct drains right thorax, right head and right neck

thoracic duct drains the rest of the body

Question 28

What does the thoracic duct drain into?

What does the right lymphatic duct drain into?

Answer 28

Thoracic duct drains into into the venous angle (at the jugulosubclavian vein).

Right lymphatic duct drains into the right venous angle.

Question 29

Lymph drainage from the nipple, areola, and lobules drain into a ________ _______ plexus.

Answer 29

subareolar (Sappey) plexus

Question 30

Damage/removal of an axillary lymph node can potentially cause _______.

Answer 30

lymphedema

Question 31

Branches of the ______ ______ nerve usually pierce the pectoralis minor to reach the deep surface of the pectoralis major.

Answer 31

medial pectoral nerve

Question 32

What artery supplies the serratus anterior?

Answer 32

Lateral thoracic artery

Question 33

What arteries supply the pec major? What about pec minor?

Answer 33

Both are supplied by the pectoral branch of the thoracoacromial trunk.

Question 34

What are the four branches of the thoracoacromial artery trunk?

Answer 34

The thoracoacromial immediately splits into CAPD:
clavicular
acromial
pectoral
deltoid