Thorax Flashcards
How many ribs are there?
How many are true? false? floating?
- 12
- 7 true, 3 false, 2 floating
Where do false ribs articulate thru?
The costal arch (cartilaginous)
Where is the sternal angle (of Louis)?
B/w sternum and manubrium (can be palpated)
Why is the sternal angle important clinically?
2nd rib articulates there (1st is covered by clavicle)
What point on the vertebrae is the sternal angle?
T4/T5
Internal intercostals: OIIA?
O: Inferior border of ribs
I: Superior border of ribs below
(*90 degrees from as if you’re putting hands in pockets)
I: Intercostal nn. (ventral rami)
A: Fix intercostal spaces during respiration. Aids forced inspiration by elevating ribs
External intercostals: OIIA?
O: Internal border of ribs
I: Superior border of ribs below
(*as if you’re putting hands in pockets)
I: Intercostal nn. (ventral rami)
A: Fix intercostal spaces during respiration. Aids forced inspiration by elevating ribs
Innermost intercostals: OIIA?
O: Internal border of ribs
I: Superior border of ribs below
I: Intercostal nn. (ventral rami)
A: Elevates ribs
Transverse thoracis m: OIIA?
O: Lower third of inner aspect of sternum and lower three costosternal junctions
I: Second to sixth costal cartilages
I: Intercostal nn. (ventral rami)
A: Depresses upper ribs
What aa. supply the anterior wall of the ribs?
What are these aa. a branch of?
- Anterior intercostal aa.
- Branch of internal thoracic, musculophrenic, and supreme phrenic aa.
What aa. supply the posterior wall of the ribs?
What are these aa. branches from?
- Posterior intercostal aa.
- Branches of the aorta and costocervical trunk
There are 11 intercostal nn., so what is the name of the 12th?
Subcostal n.
From superior to inferior, what vessels run along the ribs? Are they above or below the rib?
- v.a.n.
- below (so introduce needle from above)
Which mediastinal compartment contains the heart?
Middle mediastinum
What is asymmetrical regarding veins of the superior mediastinum?
Clinical implication?
- Left brachiocephalic v is longer than right
- Right brachiocephalic v is more vertical, left is more oblique/horizontal
- Therefore, right side is easier to enter heart
What all is contained in the superior mediastinum?
Superior mediastinum contains:
a. aortic arch
b. brachiocephalic trunk
c. left common carotid a.
d. left subclavian a.
e. superior vena cava
f. brachiocephalic v.
g. thymus
h. trachea and esophagus
i. vagus and phrenic n.
j. recurrent laryngeal
k. thoracic duct.
What does the right phrenic n. take to the diaphragm?
Right brachiocephalic v
What does the left phrenic n. take (initially) to the diaphragm?
Aorta, then other things…
What does vagus n. follow to the get to the abd cavity?
Esophagus
Patient tumor is at T3 and is compressing an artery. Which artery could it be? A. Desc. aorta B. Asc. aorta C. Brachiocephalic D. R subclavian E. Musculophrenic
C, Brachiocephalic
Patient shot in the chest. Bullet entered just below sternal angle and lodged in a vertebra posteriorly. Which vertebra? A. T2 B. T3 C. T4 D. T5 E. T6
D, T5
Pt with fx of costal cartilage of 4th rib. You could localize this on the ant. chest wall by:
A. Counting down 2 ribs from sternal angle
B. Counting down 3 ribs from sternal angle
C. Counting down 4 ribs from sternal angle
D. Counting down 2 ribs from jugular notch
E. Counting down 3 ribs from jugular notch
A, Counting down 2 ribs from sternal angle
Pt with osteosarcoma on the ant. surface of T6 vertebral body. Which artery MOST likely affected? A. R ant. intercostal a B. R post. intercostal a C. L ant. intercostal a D. L post. intercostal a
B, R post. intercostal a
At what level of the spinal column is the xiphoid process?
T9/T10
What is the sternal body composed of?
Sternebrae
What is another name for the thoracic inlet?
What is it bound by?
- AKA Superior aperture
- Manubrium, 1st rib, T1 vertebrae
What is another name for the thoracic outlet?
What is it bound by?
- AKA Inferior aperture
- Xiphoid process, costal arch, 12th rib (this aperture is closed off by diaphragm)
What veins drain the thorax?
Brachiocephalic and azygos vv.
What is contained in the middle mediastinum?
- Pericardium
- Root of lungs
- Heart and great vessels
- Phrenic n.
What is contained in the anterior mediastinum? What is the anterior border of it?
- Areolar tissue and lymph nodes
- Ant border: sternum
What is contained in the posterior mediastinum?
- Descending aorta
- Azygos and hemiazygos vv.
- Esophagus
- Vagus n.
- Thoracic splanchnic n.
- Thoracic duct
What are the 3 main parts of the pleural cavities?
- Parietal pleura (outer layer)
- Visceral pleura (covers lungs)
- Pleural recesses (potential spaces b/w parietal and visceral pleura)
What are the 3 layers of the parietal pleura?
- Costal pleura (lines ribs)
- Diaphragmatic pleura (lines diaphragm)
- Mediastinal pleura (lines the mediastinum)
What mm. do VAN run b/w?
Internal and innermost intercostal mm.
What does the azygos v drain into?
SVC @ T4 (s/p brachiocephalic)
What does internal thoracic a branch into at costal arch?
Musculophrenic and superior epigastric aa.
Is the intercostal a. on the right or left longer?
Right, due to aorta
What vertebrae does the thyroid gland span from, about?
C5-T1
What vertebrae does the trachea span from, about?
Lower cricoid cartilage border, C6-~T5 (sternal angle)
To find the thyroid gland, find the _________ and then move laterally.
Cricoid cartilage
