Respiratory Anatomy - Thorax

Question 1

Describe what the thoracic inlet is bounded by

Answer 1

First thoracic vertebrae posteriorly
First pair of ribs laterally
Costal cartilage of the first rib
Superior border of the manubrium anteriorly

Question 2

Describe what the thoracic outlet is bounded by

Answer 2

12th thoracic rib posteriorly
11th and 12th pair of ribs laterally
Costal cartilages of ribs 7-10
Xiphisternal joint anteriorly

Question 3

What level is the sternal angle?

Answer 3

At lower border of T4 vertebrae

Question 4

What are the 2 grooves on the first rib separated by and what do the grooves hold?

Answer 4

Scalene tubercle
Anterior vein lodges subclavian vein
Posterior groove lodges subclavian artery and lowest trunk of brachial plexus

Question 5

Describe features of the first rib

Answer 5

First rib is flat and broad, head possesses a single articular facet
Scalene tubercle

Question 6

Describe some features of a typical rib

Answer 6

Body, costal groove, head with 2 articular facts, Neck, tubercle, and angle

Question 7

What are the costovertebral joints for the head of the rib?

Answer 7

Head articulates with body of thoracic vertebrae with same number as rib as well as the body of vertebrae above

Question 8

What type of joints are the costovertebral joints?

Answer 8

Synovial plane joints

Question 9

What is the costovertebral joint of the tubercle of the rib?

Answer 9

Tubercle articulates with the transverse process of the thoracic vertebrae of same number as rib
This is a costotransverse joint - synovial plane

Question 10

What are the 3 intercostal muscles of the thorax?

Answer 10

External, Internal and innermost

Question 11

Between which of the intercostal muscles do the intercostal vein, artery and nerve lie?

Answer 11

Between internal and innermost intercostal muscles

Question 12

Describe the arterial supply of the thoracic wall

Answer 12

Posterior intercostal arteries (mainly descending aorta)
Anterior intercostal arteries (branches of internal thoracic artery) and branches of axillary arteries

Question 13

Describe the venous drainage of the thoracic wall

Answer 13

Azygous, hemiazygos accessory venous system and internal thoracic veins

Question 14

Describe the lymphatic drainage of the thoracic wall

Answer 14

Left side drains to thoracic duct then to left subclavian vein
Right side drains to right lymphatic duct to right subclavian vein

Question 15

Describe the lymphatic drainage of the breasts

Answer 15

Drain to axillary LN, then parasternal LN, and then abdominal LN

Question 16

Where is the transverse thoracic plane?

Answer 16

Between T4 and T5 vertebrae

Question 17

What are the 3 peripheral attachments of the diaphragm?

Answer 17

Lumbar vertebrae and arcuate ligaments, costal cartridges of ribs 7-12 and xiphoid process of the sternum

Question 18

What is the central attachment of the diaphragm?

Answer 18

Central tendon

Question 19

What are the left and right crura?

Answer 19

The parts of the diaphragm that arise from the vertebrae are tendinous in structure

Question 20

Where is the right crus?

Answer 20

Arises form L1 to L3
Some fibres of right crus surround the oesophagus opening and help prevent reflux of gastric contents into the oesophagus

Question 21

Where is the left crus?

Answer 21

Arises from L1 to L2 and their intervertebral discs

Question 22

What is the primary muscle of inspiration?

Answer 22

Diaphragm

Question 23

Describe diaphragm movement during inspiration and expiration?

Answer 23

Diaphragm contracts (flattens) and increases thoracic volume
Diaphragm relaxes and decreases thoracic volume

Question 24

What are the 3 hiatuses of the diaphragm?

Answer 24

The caval opening
The oesophageal hiatus
The aortic Hiatus

Question 25

At what level is the caval opening and what passes through?

Answer 25

T8
Passes through central tendon of the diaphragm
Transmits the inferior vena cava

Question 26

What level is the oesophageal opening and what passes through?

Answer 26

T8
Located through muscular sling of the right crus
Transmits oesophagus and both vagus nerves

Question 27

What level is the aortic opening and what passes through?

Answer 27

T12
Between the left and right crus
Transmits the aorta, azygos vein, hemiazygos vein and the thoracic duct

Question 28

What are the nerve roots of the phrenic nerve?

Answer 28

Anterior rami of C3-C5 (mainly C5)
Is both motor and sensory

Question 29

What are the motor function of the phrenic nerve?

Answer 29

Pierces and innervates the diaphragm

Question 30

What are the sensory functions of the phrenic nerve?

Answer 30

Supplies the central part of the diaphragm

Question 31

What is the sensory innervation of the diaphragm?

Answer 31

Phrenic nerve supplies central part
Intercostal nerves T7-T12 supply peripheral portion of the diaphragm