Thoracic Wall Flashcards
What consists of the sternum (superior to anterior?)?
- manubrium sterni
- body of sternum
- xiphoid process
Whats the area called between manubrium sterni and the body of sternum, and which thoracic part does it correspond to?
Sternal angle (angle of Louis) Corresponds to T2 SN
What are some good references and landmarks for the thoracic wall?
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
How many intercoastal spaces are there?
11 spaces; 12 ribs
What are the two apertures, and which one has a coastal margin?
Superior Thoracic aperture
Inferior Thoracic aperture
–> inferior has the margin
True or False: The first 7 ribs are attached to the sternum via cartilage
True
Which ribs are floating ribs and what does this mean?
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.
What is special about the 8th, 9th, and 10th ribs?
The 8th, 9th, and 10th ribs are attached to each other by costal cartilage.
How to locate the sternal angle?
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.
True or False: spinal nerve includes both sensory and motor nerves
True
Which thoracic regions have a ventral rami that form the intercoastal nerves?
T1-T11
True or False: rib fractures occur usually at the 1st rib?
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.
On the rib, where does a fracture usually happen?
Rib fractures usually occur at the angle from antero-posterior compressive forces.
What is a flail chest and how is it confirmed?
If 3 or more ribs fracture together in two or more places the resulting condition is referred to as a FLAIL CHEST.
–> X-Ray
What is a symptom of flail chest?
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
What will you see on a x-ray picture of a flail chest?
subcutaneous emphysema; air has leaked into the subcutaneous tissues from a torn pleural membrane and/or lacerated lung resulting from penetrating chest trauma
Where does the phrenic nerve originate from and what is its function?
C3-5, and helps in inspiration/exhalation
What pleura lines the apex of the lungs?
Suprapleural membrane, cervical pleura, and visceral pleura
What pleura lines the thoracic cage?
Coastal parietal pleura
What can be found between the pectoral and deltoid muscles?
Deltopectoral groove thats nests the cephalic vein which turns into axillary artery
Why is pectoralis minor important in terms axillary artery (from subclavian artery)?
divides it into three parts:
- superior thoracic artery
- thoracoacromial artery
- lateral thoracic artery
Which vessels supplies the intercostal 1-6 spaces
anterior intercostal arterioles (from internal thoracic artery)
Which vessels supply the intercostal 7-9 spaces
musculophrenic artery
What is the ventral rami of T12 called?
subcoastal nerve
What is vessels called coming from the thoracic aorta?
posterior intercostal arteries
True or False: anastomoses (ie. shunts) exists between
posterior and anterior intercostal arteries
True
What is the source of axillary and internal thoracic artery?
subclavian artery
What is a pancoast tumor and what results from it?
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)
For forced respiration which muscles are recruited in addition to main ones?
- scalenes
- sternocleidomastoid
- pectoralis major and minor
- abdominal muscles
For quiet respiration which muscles are involved?
- scalene muscles
- external intercostal muscles (for inspiration)
- internal intercostal muscles (for expiration)
- innermost intercostal muscles
- diaphragm
What precautions should be taken before performing an intercostal nerve block?
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
What is the placement difference of Intercostal Nerve Block and Thoracocentesis?
The anesthetic is provided at the inferior side of the rib whereas for the chest tube is provided at the superior side.