Thoracic I

Question 1

The mediastinum is a space that contains all the thoracic viscera except __.

Answer 1

The lungs & pleural spaces

Question 2

Which ribs are called “true ribs” and why?

Which ribs are called “false ribs” and why?

Which ribs are “floating ribs”

Answer 2

Ribs 1-7 b/c they articulate directly w/ the sternum;

Ribs 8-12 b/c they are connected to the sternum via costal cartilages of the ribs above

Ribs 11 and 12

Question 3

Which ribs are typical ribs?

Answer 3

Ribs 3-9.

NOTE: All other ribs are atypical

Question 4

What are the terminal branches of the internal thoracic vessels?

Answer 4

The superior epigastric and musculophrenic vessels.

Question 5

What are the 2 main types of pleurae, and what are they divided into?

Answer 5

1. Visceral pleura (closes over lungs)
2. Parietal pleura (4 parts):

Costal, Cervical, Diaphragmatic, mediastinal pleura

NOTE: Parietal innervated by intercostal and phrenic n. branches

Question 6

What are the 2 recesses in the thoracic cavity?

Answer 6

1. Costodiaphragmatic recess: b/w diaphragm and ribs
2. Costomediastinal recess: b/w mediastinum and thoracic wall

Question 7

The lingula of the left lung is part of which lobe?

Answer 7

The upper lobe

Question 8

What are the vessels top to bottom when looking at the hilum of the right lung

Answer 8

Right superior lobar bronchus (w/ right intermediate bonchus), Right pulmonary a.’s, Right superior pulmonary v., right inferior pulmonary v.

Question 9

What are the vessels top to bottom when looking at the hilum of the left lung?

Answer 9

Left pulmonary a., Left superior pulmonary v.’s, Left main bronchus, Left inferior pulmonary v.

Question 10

In general, most of the lower lobe projects ___ and the upper, middle (in right lung) project ___

Answer 10

posteriorly; anteriorly

Question 11

The __ arches over the right lung root, and the __ arches over the left

Answer 11

Azygos vein, aorta

Question 12

What are the 2 distinct blood supplies for the lungs?

Answer 12

1. Pulmonary a.’s carry deoxegenated blood to lungs
2. Bronchial a.’s from branches of aorta or intercostal a.’s carry oxegenated blood to lungs

Question 13

Describe the origins of the nerve supply of the lungs.

Answer 13

Parasympathetic n.’s are PREganglionic axons from the vagus n.

Sympathetic n.’s are POSTganglionic axons from the cervical and upper thoracic ganglia

Question 14

What are the sympathetic and parasympathetic effects on the lungs w/ regard to:

1. vasculature
2. bronchi
3. glands
4. sensory component

Answer 14

Sympathetic:

1. Vasoconstrict pulmonary a.’s
2. dilate bronchi
3. No effect on glands
4. Very little sensory component in airways

Parasympathetic:

1. Increase vascular leak from capillaries
2. Constrict bronchi
3. Increase mucous secretion
4. Sensory component mediates reflexes

Question 15

Which node determines the heart rate and where is it located?

Answer 15

The sinoatrial node is densely innervated and located w/in the superior part of the crista terminalis in the wall of the right atrium

Question 16

Where is the atrioventricular bundle located?

Answer 16

It passes thru the membranous interventricular septum into the muscular part, dividing into right and left bundle branches for the 2 ventricles.

Question 17

How do vagus and sympathetic axons affect efferent n. fibers in the heart w/ respect to:

1. Heart rate
2. contractile force
3. coronary a.’s

Answer 17

Branches of vagus n.:

1. Dec. HR
2. Dec. Contractile force
3. Constrict coronary a.’s

Sympathetic axons:

1. Inc. HR
2. Inc Contractile force
3. Dilate coronary a.’s