Lecture 5: Applied anatomical concepts

Question 1

What are the two types of breathing?

Answer 1

Thoracic and abdominal

Question 2

What is the effect of inspiration on volume and pressure in the thorax?

Answer 2

Increase in intra-thoracic diameter/volume

Decrease in intra-pleural pressure

Question 3

What are the three changes in dimension that occur during inspiration?

Answer 3

Lateral/Transverse diameter

Anterior Posterior diameter

Vertical diameter

Question 4

Describe the change to the lateral diameter of the thorax during inspiration?

Answer 4

Lateral edges of ribs are elevated supero-laterally and the lateral diameter of thoracic cavity increases

Results in an increase in the transverse diameter of chest cavity

Bucket handle movement

Question 5

Describe the change to the anterior/posterior diameter of the thorax during inspiration?

Answer 5

Anterior ends of ribs are raised during inspiration

Elevation causes sternum to also be raised

Movement is facilitated by costal cartilages

Results in an increase in antero-posterior diameter of chest cavity

Pump handle movement

Question 6

What is the effect of expiration on volume and pressure in the thorax?

Answer 6

Decrease in intra-thoracic diameter/volume

Increased intra-pleural pressure results in air being expelled from lungs

Question 7

When is forced (active) expiration required?

Answer 7

Coughing
Playing wind instruments
Exertion

Question 8

What muscles are used for quiet inspiration?

Answer 8

External intercostals
Scalene muscles
Plus the diaphragm

Question 9

What muscles are used for quiet expiration?

Answer 9

Passive

Question 10

What muscles are used for forced inspiration?

Answer 10

External intercostals
Scalene muscles
Plus the diaphragm

AND

Pectoral muscles
Sternocleidomastoid
Latissimus dorsi

Question 11

What muscles are used for forced expiration?

Answer 11

Internal intercostals
Oblique and transverse abdominal muscles
Quadratus lumborum

Question 12

How do you increase the vertical diameter of the thorax?

Answer 12

Via diaphragm which forms floor of thoracic cavity

Descends upon contraction up to 5 -10 cm compressing abdominal organs

↑ vertical diameter of thorax

Question 13

What is abdominal breathing?

Answer 13

When the diaphragm in contracted

Reduced during pregnancy

Question 14

What is the diaphragm?

Answer 14

Sheet of skeletal muscle with a central tendon

Question 15

What is attached to the middle of the tendon on the superior surface of the diaphragm?

Answer 15

The pericardium

Question 16

What lines the superior surface of the diaphragm?

Answer 16

Diaphragmatic parietal pleura

Question 17

What are the three sections of the diaphragm?

Answer 17

Sternal
Costal
Lumbar

Question 18

Describe the sternal part of the diaphragm.

Answer 18

2 muscular slips sometimes leaving the anteromedian gap

Question 19

Describe the costal part of the diaphragm.

Answer 19

From inferior 6 costal cartilages

Question 20

Describe the lumbar part of the diaphragm.

Answer 20

Part that gives rise to the medial and lateral arcuate ligaments and is anchored by the musculotendinous right and left crura

Question 21

What is the diaphragm used for?

Answer 21

Coughing, laughing, urinating and defecation, lifting heavy objects (braces vertebral column)

Question 22

What are the three openings in the diaphragm?

Answer 22

Opening for Inferior Vena Cava
Oesophageal hiatus
Aortic hiatus

Question 23

What provides the blood supply of the diaphragm?

Answer 23

Superior & inferior phrenic arteries

Question 24

Where do the phrenic nerves originate?

Answer 24

C3, C4, C5

Question 25

What gets sensory supply from the phrenic nerve?

Answer 25

Pericardium

Parietal pleura (mediastinal and diaphragmatic – central only)

Parietal peritoneum

Central region of diaphragm

Question 26

What gets motor supply from the phrenic nerve?

Answer 26

Diaphragm (sole supply)

Question 27

Where does the phrenic nerve enter the superior mediastinum?

Answer 27

Lateral to the Vagus nerve

Question 28

Describe the pathway of the right phrenic nerve.

Answer 28

Passes on right wall of SVC to right side of pericardium, descends on pericardium over right atrium to diaphragm (near IVC orifice)

Question 29

Describe the pathway of the left phrenic nerve.

Answer 29

Runs over aortic arch and pulmonary trunk, descends on pericardium over left ventricle to diaphragm (near cardiac apex)

Question 30

What regulates the SA node?

Answer 30

Autonomic nerves via the Cardiac Plexus

Parasympathetic fibres - Vagus nerve

Sympathetic fibers - T1-5 levels of spinal cord and associated paravertebral ganglia

Question 31

What is a phancoast tumour?

Answer 31

Cancer located at apex of the lung

If on left side can cause recurrent laryngeal nerve compression

Vocal cord paralysis = Hoarseness

Question 32

What is used to locate left vagus nerve?

Answer 32

Ligamentum arteriosum