Thoracic Wall

Question 1

What consists of the sternum (superior to anterior?)?

Answer 1

• manubrium sterni
• body of sternum
• xiphoid process

Question 2

Whats the area called between manubrium sterni and the body of sternum, and which thoracic part does it correspond to?

Answer 2

Sternal angle (angle of Louis)
Corresponds to T2 SN

Question 3

What are some good references and landmarks for the thoracic wall?

Answer 3

Line:
Midline (midsternal line)
Midclavicular line
Mamillary line

Landmarks:
Sternal Angle –> T2 SN (spinal nerve)
Nipple –> T4 SN
Xiphoid Process –> T6/7 SN & Coastal margin/angle

Question 4

How many intercoastal spaces are there?

Answer 4

11 spaces; 12 ribs

Question 5

What are the two apertures, and which one has a coastal margin?

Answer 5

Superior Thoracic aperture
Inferior Thoracic aperture
–> inferior has the margin

Question 6

True or False: The first 7 ribs are attached to the sternum via cartilage

Answer 6

True

Question 7

Which ribs are floating ribs and what does this mean?

Answer 7

11th and 12th –> are not attached in any way to the sternum; they move up and down in the anterior chest, allowing for full chest expansion.

Question 8

What is special about the 8th, 9th, and 10th ribs?

Answer 8

The 8th, 9th, and 10th ribs are attached to each other by costal cartilage.

Question 9

How to locate the sternal angle?

Answer 9

If you find the sternal notch, walk your fingers down the manubrium a few centimeters until you feel a distinct bony ridge. This is the sternal angle.

Question 10

True or False: spinal nerve includes both sensory and motor nerves

Answer 10

True

Question 11

Which thoracic regions have a ventral rami that form the intercoastal nerves?

Answer 11

T1-T11

Question 12

True or False: rib fractures occur usually at the 1st rib?

Answer 12

False:
Fractures of the 1st rib are uncommon because of its strength and also because it is partly protected by the clavicle. A tremendous force is generally required to fracture the 1st rib, which if fractured, usually indicates the patient has undergone severe trauma and should raise the suspicion of
other serious injuries to the chest and elsewhere.

Question 13

On the rib, where does a fracture usually happen?

Answer 13

Rib fractures usually occur at the angle from antero-posterior compressive forces.

Question 14

What is a flail chest and how is it confirmed?

Answer 14

If 3 or more ribs fracture together in two or more places the resulting condition is referred to as a FLAIL CHEST.

–> X-Ray

Question 15

What is a symptom of flail chest?

Answer 15

Paradoxical trauma: the affected area draws
in when the patient breathes in and the rest of the chest expands, and the affected area moves outwards as the patient exhales and the rest of the chest contracts

Question 16

What will you see on a x-ray picture of a flail chest?

Answer 16

subcutaneous emphysema; air has leaked into the subcutaneous tissues from a torn pleural membrane and/or lacerated lung resulting from penetrating chest trauma

Question 17

Where does the phrenic nerve originate from and what is its function?

Answer 17

C3-5, and helps in inspiration/exhalation

Question 18

What pleura lines the apex of the lungs?

Answer 18

Suprapleural membrane, cervical pleura, and visceral pleura

Question 19

What pleura lines the thoracic cage?

Answer 19

Coastal parietal pleura

Question 20

What can be found between the pectoral and deltoid muscles?

Answer 20

Deltopectoral groove thats nests the cephalic vein which turns into axillary artery

Question 21

Why is pectoralis minor important in terms axillary artery (from subclavian artery)?

Answer 21

divides it into three parts:

1. superior thoracic artery
2. thoracoacromial artery
3. lateral thoracic artery

Question 22

Which vessels supplies the intercostal 1-6 spaces

Answer 22

anterior intercostal arterioles (from internal thoracic artery)

Question 23

Which vessels supply the intercostal 7-9 spaces

Answer 23

musculophrenic artery

Question 24

What is the ventral rami of T12 called?

Answer 24

subcoastal nerve

Question 25

What is vessels called coming from the thoracic aorta?

Answer 25

posterior intercostal arteries

Question 26

True or False: anastomoses (ie. shunts) exists between

posterior and anterior intercostal arteries

Answer 26

True

Question 27

What is the source of axillary and internal thoracic artery?

Answer 27

subclavian artery

Question 28

What is a pancoast tumor and what results from it?

Answer 28

Malignant tumor involving the apex of the lung that compresses brachial plexus, sympathetic trunk, and subclavian artery and results to horner’s syndrome (ptosis [drooping eyelid], miosis [pupillary constriction], anhidrosis [lack of sweating]), and shoulder & upper extremity pain & weakness (due lower trunk brachial plexopathy)

Question 29

For forced respiration which muscles are recruited in addition to main ones?

Answer 29

• scalenes
• sternocleidomastoid
• pectoralis major and minor
• abdominal muscles

Question 30

For quiet respiration which muscles are involved?

Answer 30

• scalene muscles
• external intercostal muscles (for inspiration)
• internal intercostal muscles (for expiration)
• innermost intercostal muscles
• diaphragm

Question 31

What precautions should be taken before performing an intercostal nerve block?

Answer 31

since the intercostal nerve branch into collaterals, they overlap into the adjacent
intercostal spaces one must anesthetize one intercostal space above and one space below the one requiring the block to achieve complete anesthesia

Question 32

What is the placement difference of Intercostal Nerve Block and Thoracocentesis?

Answer 32

The anesthetic is provided at the inferior side of the rib whereas for the chest tube is provided at the superior side.