Anatomy - The Thoracic cage

Question 1

Describe the external intercostal muscle?

Answer 1

• Only attached to the ribs 1-11 (not over costal cartilages)
• Runs down and medially across ribs (hands in pockets)
• form a sheet at the most anterior end of the ribs around the articulation with vertebrae at the back
• Originate at the lower border of the rib, inserting into the superior border of the rib below

Question 2

Describe internal intercostal muscle?

Answer 2

• Separated from external intercostal muscle by a plural membrane
• run 90 degrees to external intercostal muscle (hands on chest)
• Originates from the lateral edge of the costal groove
• inserts into the superior surface of the rib below.

Question 3

What membrane connects the cartilages between articulating rips?

Answer 3

anterior coastal membrane

Question 4

What direction does the Oblique muscle and membrane run?

Answer 4

Same as external intercostal muscle (hands in pocket)

Question 5

How are the intercostal muscles innervated?

Answer 5

Intercostal nerves T1-T11

Question 6

What arteries supply the abdominal wall and diaphragm?

Answer 6

internal mammary arteries (aka internal thoracic arteries)

Question 7

What is the difference between the visceral pleura and parietal pleura?

Answer 7

• visceral pleura is directly in contact with the lungs
• parietal pleura is directly on the chest wall, internal surfaces of the thoracic cavity

Question 8

What is contained within the pleural cavity and what is its function?

Answer 8

• Serous fluid
• lubricates visceral layers
• creates tension between visceral layers so when thorax expands so do the lungs

Question 9

Describe the pleural recesses?

Answer 9

• Where the pleural cavity is not completely filled by the lungs, parietal pleura touches
• costodiaphragmatic
• costomediastinal
• locations of pleural effusion

Question 10

Describe the neurovascular supply of the 2 pleurae?

Answer 10

• Parietal pleura - sensitive to pain, pressure and temperature via phrenic and intercostal nerves, supplied by Intercostal arteries
• Visceral pleura - only detects stretch, autonomous innervation from pulmonary plexus, supplied by bronchial arteries

Question 11

Name the connection between the lung and mediastinum? What does it contain?

Answer 11

• Called the hilum
• 1 pulmonary artery
• 2 pulmonary veins
• bronchus
• lymphatic vessels
• branches of vagus and sympathetic nerves

Question 12

What can make impressions on the left and right lungs?

Answer 12

• Major mediastinal structures
• shows close contact ie spreading disease

Question 13

Describe the diaphragm? How is it innervated?

Answer 13

• non-contracting central tendon
• peripheral muscle fibres
• innervated by phrenic nerves arises from C3, 4 and 5

Question 14

What are the 2 effects of the diaphragm contracting?

Answer 14

• Glottis is open and air is drawn into the lungs
• blood is drawn from the inferior vena cava into the right atrium

Question 15

What is a V/Q scan?

Answer 15

• V - ventilation, breath in radioactive gas alveoli usage is visualized
• Q - perfusion, technetium is injected into the blood, visualizes blockages of pulmonary arteries

Question 16

What is an intercostal recession? What is it’s clinical relevance?

Answer 16

• intercostal spaces stuck in during inspiration
• sign of advanced respiratory distress, especially in the first 6th months of life

Question 17

What is grafted to the left anterior descending coronary artery when it is narrowed?

Answer 17

left internal mammary artery

Question 18

What is the function of the lungs?

Answer 18

Oxygenates blood by bringing inspired air into contact with O2 poor blood in the pulmonary capillaries.

Question 19

What does the internal thoracic artery branch into?

Answer 19

1. Musculophrenic - supplies the diaphragm.
2. Superior epigastric arteries - supplies the front of the abdomen.

Question 20

What is the pleural cavity?

Answer 20

A potential space between the visceral and parietal pleura.

Question 21

Name 2 functions of the serous fluid within the pleural cavity?

Answer 21

1. Lubricates the pleurae.
2. Creates a surface tension helping the lungs to expand on inspiration.

Question 22

What branch does the right main bronchus give off outside of the right lung?

Answer 22

Superior lobar bronchus.

Question 23

What other smaller vessels are found at the hilum of the lung?

Answer 23

1. Bronchial arteries. 2. Pulmonary plexus of autonomic nerves. 3. Lymph nodes.

Question 24

Which lung are inhaled foreign bodies most likely to be found in and why?

Answer 24

The right lung. The right main bronchus is shorter and more vertical.

Question 25

How many lobes does the right lung have and what are they called?

Answer 25

3 lobes. Superior, middle and inferior.

Question 26

How many lobes does the left lung have and what are they called?

Answer 26

2 lobes. Superior and Inferior.

Question 27

What is the fissure in the left lung called?

Answer 27

Oblique (lies along 6th rib).

Question 28

What are the fissures in the right lung called?

Answer 28

Horizontal (extends from mid-axiallry line anteriorly along the 4th rib) and Oblique (lies along 6th rib).

Question 29

Name the 3 surfaces of the lungs.

Answer 29

1. Costal
2. Mediastinal
3. Diaphragmatic

Question 30

Name the 3 borders of the lungs.

Answer 30

1. Anterior
2. Posterior
3. Inferior

Question 31

Describe the innervation of the lungs?

Answer 31

1. Parasympathetic innervation derived from vagus nerve
2. Sympathetic innervation derived from sympathetic trunks
3. Visceral afferent - conducts pain impulses to sensory ganglion

Question 32

What is the action of parasympathetic innervation in the lung?

Answer 32

Bronchoconstriction and vasodilation of pulmonary vessels.

Question 33

What is the action of sympathetic innervation in the lung?

Answer 33

Bronchodilation and vasoconstriction of vessels that are poorly ventilated.

Question 34

What is the surface marking for the apex of the lung?

Answer 34

2 finger breadths (3cm) above the medial clavicle in the neck.

Question 35

What are the surface markings for the lower border of the lung?

Answer 35

6th rib anteriorly, 8th rib in the mid-axillary line and 10th rib posteriorly.

Question 36

What are the surface markings for the lower border or the pleural cavity?

Answer 36

8th rib anteriorly, 10th rib in the mid-axillary line and 12th rib posteriorly.