Thoracic IIII

Question 1

The thymus has __ lobes consisting of ___.

Why is it difficult to see in adults?

Answer 1

2; lymphoid & connected tissue;

It is largest at birth and puberty, but involutes in adults, particularly after diseases

Question 2

The phrenic n.’s are formed from:

Answer 2

anterior primary rami of spinal nerves C3,4,5

Question 3

The bifurcation of the trachea is at what vertebral level in expiration?

Answer 3

T4/5

Question 4

From what a. does the esophagus receive blood?

Answer 4

the Inferior thyroid a.

Question 5

The esophagus passes thru the diaphragm at the level of which thoracic vertebra?

Answer 5

T10

Question 6

What are the superior and inferior vertebral boundaries for the descending thoracic aorta?

Answer 6

T4/T12

Question 7

There are 11 posterior intercostal a.’s. Where do they arise from? (2 structures)

Answer 7

The first 2 arise from the costocervical trunk, a branch of the subclavian a.

The other 9 pairs arise from the descending thoracic aorta.

Question 8

What are the 2 azygos veins and what do they do?

Answer 8

The right side has the azygos v., the left side has the (smaller) hemiazygos v.

They drain the posterior side of the thoracic wall.

Question 9

What are the 3 types of splanchnic n.’s and where do their axons originate from?

These are __ganglionic __ fibers.

Answer 9

Greater splanchnic n.: axons from 5th-10th sympathetic ganglia,

Lesser splanchnic n.: axons from T10&T11,

Least splanchnic n.: axons from T12;

These are PREganglionic sympathetic n. fibers

Question 10

All preganglionic sympathetic cell bodies are located in the spinal cord b/w:

Answer 10

The first thoracic and second lumbar levels.