Chapter 1 - Introduction

Question 1

Boundaries of thoracic cage

Answer 1

Anteriorly: Sternum
Posteriorly: Thoracic vertebrae
Each side: 12 ribs

Question 2

Describe the thoracic cage in children

Answer 2

• In children, the chest wall is highly elastic.
• Fractures are therefore rare.
• Fractures occur mostly due to violence.
• Weakest point is at the angle.
• Upper two ribs are protected by clavicle and floating ribs are least commonly injured.

Question 3

Hiccups

Answer 3

• Due to spasmodic contractions of diaphragm accompanied by closed glottis.
• Stimulated by gastric irritation.
• May also be due to phrenic nerve irritation, uraemia or hysteria.

Question 4

Boundaries of inlet of thorax

Answer 4

Anteriorly: Manubrium sterni
Posteriorly: Body of T1
Each side: 1st rib

The plane of the inlet is directed forwards and downwards at an angle of 45.

Question 5

Sibson’s fascia

Answer 5

1. suprapleural membrane
2. Partially separates thorax from neck
3. Triangular
4. Apex: transverse process of C7
5. Base: inner border of 1st rib.
6. Flattened tendon of scalenus minimus
7. Inferior surface: Fused to cervical pleura
8. Superior surface: related to subclavian vessels
9. Provides rigidity to thoracic inlet so that root of neck is not puffed during respiration.

Question 6

Structures passing through thoracic inlet

Answer 6

1. Oesophagus
2. Trachea
3. Brachiocephalic A
4. Left common carotid and left subclavian A
5. RL brachiocephalic V
6. Internal thoracic A
7. Superior intercoastal A
8. Posterior intercoastal V
9. Inferior thyroid V
10. Phrenic N
11. Vagus N
12. Sympathetic trunk
    !3. Sternothyroid, Sternohyoid, Longus colli

Question 7

Boundaries of outlet of thorax

Answer 7

Anteriorly: Infrasternal angle between coastal margins
Posteriorly: T12
Sides: Cartilages of 7th-12th ribs

Question 8

3 large openings in diaphragm

Answer 8

1. Vena caval
2. Oesophageal
3. Aortic

Question 9

Vena caval opening

Answer 9

• T8
• Quadrilateral
  1. Inferior vena cava
  2. Right phrenic nerve
  3. Lymphatic of liver

Question 10

Oesophageal opening

Answer 10

• T10
• Elliptical
  1. Oesophagus
  2. Vagal trunks
  3. Left gastric vessels

Question 11

Aortic opening

Answer 11

• T12
• Rounded
  1. Aorta
  2. Thoracic duct
  3. Azygos vein

Question 12

Small openings of diaphragm

Answer 12

1. Superior gastric A through space of Larrey
2. Musculophrenic A
3. Greater and lesser splanchnic N
4. Left phrenic N pierces left cupola

Question 13

space of Larrey

Answer 13

Between slip of xiphoid process and 7th coastal cartilage slip of diaphragm

Question 14

Thoracic inlet syndrome

Answer 14

• Subclavian artery and 1st thoracic N pass over first rib
• They may be pulled or pressed by cervical rib or by scalenus anterior
• Vascular/Neural symptoms or both