Thoracic Wall and Pectoral Region

Question 1

What are the parts of the sternum?

Answer 1

Manubrium, body, xiphoid process

Question 2

Where is the sternal angle of louis?

Answer 2

At the intersection of manubrium and body of sternum, which is also where the costal cartilage of the second rib meets the sternum

Question 3

Three abdominal organs protected by the rib cage and which ribs?

Answer 3

Liver (right ribs 9-11), Kidneys (ribs 11 and 12), Spleen (left ribs 9-11)

Question 4

Two types of joints attaching ribs to vertebrae and where each attach

Answer 4

Costovertebral joints (attach heads of ribs to bodies of corresponding vertebra and vertebra above) and Costotransverse joints (attach tubercle of rib to transverse process of vertebra)

Question 5

Describe the three types of ribs and the number of each

Answer 5

7 pairs of true ribs, 3 pairs of vertebrochondral (false) ribs, 2 pairs of floating ribs

Question 6

What three ribs have an atypical number of vertebral attachments

Answer 6

Ribs 1, 11, and 12. They only attach to their corresponding vertebrae

Question 7

Costochondritis

Answer 7

Soreness of either the interface of rib and costal cartilage or costal cartilage and sternum, often caused by excessive coughing

Question 8

Where does the scalenus anterior m (anterior scalenus muscle) attach?

Answer 8

Arises from transverse processes of 3-6 cervical vertebra and attaches to scalene tubercle of first rib (something special about 1st rib)

Question 9

Sternebrae

Answer 9

The four (usually fused in adults) sections which comprise the body of the sternum

Question 10

Why is the sternum an optimal target for bone marrow biopsy?

Answer 10

It is rich in bone marrow, and it is superficial and easy to access

Question 11

Upon inspiration which way do the sternum and ribs move respectively?

Answer 11

Sternum moves anterosuperiorly (forward and up), ribs move laterosuperiorly (out and up). Both motions expand the chest cavity

Question 12

Give the posterior, lateral, and medial borders of the breast as well as which ribs it is anterior to

Answer 12

Posterior - The retro-mammary space (anterior to deep fascia of pec muscle), Lateral - Midaxillary line, Medially - The parasternal margin. The breast is located from the 2nd to the 6th rib

Question 13

Give the flow of milk within the breast

Answer 13

Mammary gland lobule to lactiferous duct to lactiferous sinus to areola and nipple

Question 14

How many lactiferous ducts empty into each lactiferous sinus?

Answer 14

One

Question 15

Ligaments of Cooper

Answer 15

Suspensory ligaments in the breast (especially superior breast) which support the weight of the breast

Question 16

What does the areola do?

Answer 16

Secrete oils during breast feeding

Question 17

Give the innervation of the breast, and specifically the nipple

Answer 17

Breast - Intercostal nerves 2-6, Nipple - Intercostal nerve 4

Question 18

Name the 4 arterial branches of the breast and trace each back to a major artery (against the flow of blood)

Answer 18

Lateral mammary branches (lateral thoracic –> Axillary), Medial mammary branches (Internal thoracic –> Subclavian), Mammary branches of deep regions of the breast (Intercostal arteries), Pectoral branches of thoracoacromial artery (Thoracoacromial –> Axillary)

Question 19

What major veins do veins of the breast drain into?

Answer 19

Axillary, internal thoracic, and intercostal veins

Question 20

Give the two primary places to which lymph of the breast drains and the approximate percentage going to each location

Answer 20

75 percent to superior and lateral to Axillary nodes and most of remainder going to parasternal nodes

Question 21

Give the arteries that branch off the axillary artery in each of its three parts

Answer 21

First part - superior thoracic a, Second part - Thoracoacromial a, Lateral thoracic a, Third Part - Subscapular a, Ant. humeral circumflex a, Post. humeral circumflex

Question 22

What artery does the internal thoracic arise from, where does it bifurcate, and into what two arteries?

Answer 22

Subclavian artery, at 6th intercostal space bifurcates into musculophrenic artery and superior epigastric artery

Question 23

What arteries are given off by the internal thoracic and with what do they anastomose?

Answer 23

The anterior intercostal arteries, they anastomose with the posterior intercostal arteries (which are branches of the descending aorta)

Question 24

Give venous drainage for the anterior and posterior thoracic wall respectively

Answer 24

Internal thoracic veins, Azygos system

Question 25

Between which two layers of intercostal muscle do intercostal nerves and vessels run?

Answer 25

Between internal and innermost

Question 26

Where do collateral branches of intercostal vessels and nerves run relative to other intercostal vessels?

Answer 26

Inferior. The collateral branches cross the intercostal space and run superior to the rib below, whereas the regular branches run inferior to the rib above

Question 27

Give the branches given off by the subclavian artery, which part of the subclavian each branches off from, and the mnemonic for remembering these

Answer 27

First Part - Vertebral Artery a, Internal Thoracic a, Thyrocervical Trunk. Second Part - Costocervical trunk. Third (or Second) part - Dorsal Scapular a. Mnemonic is VITamin C and D (VITCD)

Question 28

What artery runs down the trapezius side by side with the accessory nerve (CN XI)?

Answer 28

The superficial branch of the transverse cervical artery

Question 29

The long thoracic and thoracodorsal nerves run similar courses, give two ways these two nerves can be distinguished

Answer 29

1) The thoracodorsal nerve originates from the brachial plexus, whereas the long thoracic originates from C5,C6 and C7 in the neck. 2) The long thoracic runs along the medial (trunk wall) aspect of the axilla, the thoracodorsal runs along the lateral/posterior (upper limb) aspect of the axilla down the arm.