Thorax 1

Question 1

what is the function of the external, internal, and innermost intercostal muscles? respectively.

Answer 1

• External intercostal mm. - inspiration
• Internal intercostal mm. - expiration
• Innermost intercostal mm. - expiration

Question 2

Sternum - Function

Answer 2

Protect heart, lungs, & major blood vessels from injury

Question 3

What thoracic vertebra (and ribs) do the following landmarks correspond to:
- suprasternal notch
- sternal angle
- xiphisternal joint (between body & xiphoid process)

Answer 3

• Suprasternal notch = T2-T3 (rib 1)
• Sternal angle = T4-T5 (rib 2)
• Xiphisternal joint = T8-T9

Question 4

What are the 3 types of ribs

Answer 4

• True ribs (1st-7th) - directly articulate with sternum
• False ribs (8th-10th) - indirectly articulate with sternum
• Floating ribs (11th & 12th) - do not articulate with sternum

Question 5

What ribs are described as ‘typical’?

Answer 5

3rd - 9th

Question 6

What ribs are described as atypical?

Answer 6

1st, 2nd, 10th, 11th, 12th

Question 7

Atypical feature/s of 1st rib

Answer 7

• Scalene tubercle
• Grooves for subclavian vessels (v. & a.)

Question 8

Atypical feature/s of 2nd rib

Answer 8

Rough tuberosity for serratus anterior m.

Question 9

What are the atypical feature/s of the 10th rib

Answer 9

Only 1 facet (for articulation w. its numerically corresponding vertebra)

Question 10

What are the atypical feature/s of the 11th & 12th ribs

Answer 10

• Only one facet (articulate w. correspondign vertebra)
• No neck
• No tubercle

Question 11

Features of typical ribs

Answer 11

• Head: 2 articular facets
• Neck
• Tubercle (facet for tubercle articulates w. transverse process of vertebrae)
• Shaft/body: costal angle & costal groove

Question 12

1st rib - Does the subclavian v. pass anteriorly or posteriorly to the subclavian a.

Answer 12

Subclavian v. passes anteriorly to subclavian a.

Question 13

What is the joint between each rib and its costal cartilage

Answer 13

Costochondrial joint

Question 14

Distinguish lamina & pedicle

Answer 14

Pedicle - bridge vertebral body (closer to penis)
Lamina - connects transverse & spinous processes

Question 15

What is the costal margin?

Answer 15

The margin formed by the cartilages of ribs 7-10

Question 16

What important structures pass through the diaphragm - from the thorax to the abdomen (and at what levels)?

Answer 16

VOICE OF AMERICA (VOA)
- Inferior Vena cava (T8)
- Oesophagus (T10) + - Vagus nerves (T10)
- descending Aorta (T12)

Remember:
T8 - vena cava (8 letters)
T10 - oesophagus (10 letters)
T12 - aortic hiatus (12 letters)

Question 17

What is the joint between the sternal body and xiphoid process

Answer 17

xiphisternal joint

Question 18

What is the main nerve innervating the diaphragm?

Answer 18

Phrenic nerve (C3,4,5)
* Remember: C3,4 & 5 keep the diaphragm alive

Question 19

What nerve innervates the internal throacic muscles

Answer 19

Intercostal nerves (T1-T11)

Question 20

Where do the post. and ant. intercostal arteries originate from?

Answer 20

Post. intercostal artery - thoracic aorta
Ant. intercostal artery - internal thoracic a.

Question 21

What are the 2 layers of pulmonary pleura

Answer 21

• Parietal pleura
• Visceral pleura (inner)

Question 22

What fissures separate the lungs?

Answer 22

Right lung (3 lobes):
- Horizontal fissure - separates upper & middle lobes
- Oblique fissure - separates middle & lower lobes

Left lung (2 lobes):
- Oblique fissure - separates upper & lower lobes