Chest Wall and Diaphragm Practical 1.2.14

Question 1

what are the ‘true ribs’

Answer 1

Ribs 1 – 7 (‘true ribs’) articulate directly with the sternum via their costal cartilage

Question 2

what are the ‘false ribs’

Answer 2

Ribs 8 – 10 (‘false ribs’) articulate indirectly via the costal cartilage of its superior rib.

Question 3

what are the floating ribs?

Answer 3

Ribs 11 and 12 (‘floating ribs) do not articulate with the sternum.

Question 4

what ribs are typical

Answer 4

• Typical: Ribs 3 – 9 (share common features)

Question 5

what ribs are atypical?

Answer 5

• Atypical: Ribs 1, 2, 10, 11 and 12 (each have their own distinctive features)

Question 6

what rib has the scalene tubercle?

Answer 6

1st rib

Question 7

What muscle attaches to the scalene tubercle?

Answer 7

Scalenus anterior

Question 8

Which major blood vessels pass across the superior surface of the first rib immediately anterior and posterior to this muscle attachment?

Answer 8

• Anterior: subclavian vein
• Posterior: subclavian artery

Question 9

• Which ribs articulate with the sternum at the sternal angle?

Answer 9

2nd Ribs

Question 10

• What vertebral level is indicated by the sternal angle?

Answer 10

T4/T5

Question 11

• What other anatomical landmarks are located at the sternal angle?

Answer 11

Junction between ascending aorta and arch of the aorta
Junction between the arch of the aorta and decending aorta
Bifurcation of trachea. See picture below, where the middle dotted line is the transverse thoracic plane.

Question 12

what motion increases the transverse dimension?

Answer 12

bucket handle motion of the ribs

Question 13

what motion increases the AP dimension?

Answer 13

pump handle action of the sternum

Question 14

what motion increases the vertical dimension

Answer 14

inferior movement of the diaphragm

Question 15

• What articulate with the manubrium of the sternum?

Answer 15

• Clavicle, cartilages of 1st ribs, part of the cartillages of 2nd ribs

Question 16

• What articulate with the body of the sternum?

Answer 16

• Cartilages of Ribs 2-7 (and 8-10 indirectly)

Question 17

A t which vertebral level do these structures pass through the diaphragm?
Inferior Vena Cava
Esophagus
Aorta

Answer 17

Vena Cava – T8
Esophagus - T10
Aorta – T12

Question 18

• What are the root values for the phrenic nerve?

Answer 18

C3,4,5 (keeps the diaphragm alive!)

Question 19

• What information is carried to/from the diaphragm in the phrenic nerve?

Answer 19

All motor information. Sensory information for the central parts of the diaphragm.

Question 20

• What other nerves innervate the diaphragm?

Answer 20

The peripheral parts of the diaphragm receive sensory innervation from lower intercostal and subcostal nerves.

Question 21

• Why do you think irritation of the diaphragm sometimes causes pain in the shoulder?

Answer 21

This is due to referred pain. Since the phrenic nerve originates from cervical levels, irritation of the diaphragm (e.g. liver abscesses or gall stones, among many other pathologies) can lead to pain in other areas supplied by the same spinal cord region i.e. the shoulder region

Question 22

• Between which two layers of the intercostal muscles will you find the intercostal neurovascular bundle?

Answer 22

Between internal and innermost intercostals

Question 23

• Is the neurovascular bundle located in the superior or inferior portion of each intercostal space?

Answer 23

Superiorly, at the inferior aspect of the upper rib

Question 24

• What is the name of the groove on the corresponding rib where the neurovascular bundle runs?

Answer 24

Subcostal groove

Question 25

• With this knowledge, where would you insert a needle or chest drain (with respect to the ribs) when attempting to access the thoracic cavity (e.g. in a patient with pneumothorax)?

Answer 25

Just above the superior border of a rib

Question 26

• Which arteries can be found in the intercostal neurovascular bundles?

Answer 26

Anterior and posterior intercostal arteries

Question 27

• From where do these arteries arise?

Answer 27

Anterior: from internal thoracic artery or its branch (musculophrenic a.)
Posterior: from thoracic descending aorta.

Question 28

• Which veins can be found in the intercostal neurovascular bundles?

Answer 28

Anterior and posterior intercostal veins

Question 29

• Where do these veins drain?

Answer 29

Anterior: internal thoracic vein, or musculophrenic vein
Posterior: Azygous system

Question 30

• Which nerves are responsible for innervating the intercostal muscles?

Answer 30

intercostal nerves – from anterior rami of thoracic spinal nerves

Question 31

1. A patient has a spinal cord injury at vertebral level C6. Which of the following are a likely consequence.
   a) Preservation of all motor and all sensory function to the diaphragm
   b) Loss of all motor and sensory innervation to the diaphragm
   c) Preservation of motor function but loss of all sensory innervation to the diaphragm
   d) Presentation of all sensory function but loss of all motor function to the diaphragm
   e) Preservation of motor function but loss of some sensory function to the diaphragm

Answer 31

e

Question 32

2. During normal respiration, movements in the thoracic cage allow the sequential increase and decrease in thoracic volume. Which of the following statements is true.
   a) The bucket handle movement of the ribs increases A-P dimension
   b) The pump handle motion of the sternum increases transverse dimension
   c) The decent of the diaphragm during inspiration increases vertical dimension
   d) The descent of the diaphragm during expiration decrease vertical dimension
   e) The pump hand motion of the sternum increases vertical dimension.

Answer 32

c