Diaphragm (dave's notes)

Question 1

Define the diaphragm

Answer 1

A thin sheet of muscle as a derivative of the inner layer, with its purpose being for respiration.

Question 2

What anchors the diaphragm to the vertebrae? Which is largest?

Answer 2

The left and right crura. The right is larger than the left.

Question 3

What are the attachments of the right crus? What path does this follow? Where is their innervation from?

Answer 3

L1-3. Fibres from the right loop around to the left of the oesophagus and sling this. Innervated from the left.

Question 4

What are the attachments of the left crus?

Answer 4

L1-2

Question 5

Where is the median arcuate ligament found?

Answer 5

Between and behind both curs.

Question 6

From what does the median arcuate ligament arise?

Answer 6

The median arcuate ligament is a thickening of the psoas fascia

Question 7

From what does the lateral arcuate ligament arise?

Answer 7

The lateral arcuate ligament is a thickening of th elumbar fascia (quadratus lumborum).

Question 8

The median and lateral arcuate ligaments also give off muscle fibres. From where else do diaphragmatic muscles slips arise?

Answer 8

From the ribs, Tansversus abdominus, and the xiphisternum

Question 9

Describe the central tendon of the diaphragm

Answer 9

The central tendon is shaped like a three leaf clover pointing forward, with lateral leaves towards the paravertebral gutters.

Question 10

Where is the vena caval opening in the diaphragm?

Answer 10

Between the central and right leaves of the central tendon

Question 11

List the diaphragmatic openings

Answer 11

Aorta, azygous and thoracic duct
Oesophagus, vagal trunks, oesophageal branches of the left gastric vessels
Hemiazygous vein
Greater and lesser splanchnic nerves
Sympathetic trunk
Subcostal nerve and vessels
Left phrenic nerve
Neurovascular bundles of T7-11
Epigastric vessels
Extraperitoneal lymph vessels

Question 12

What passes through the aortic opening? At what level is this?

Answer 12

T12.

Aorta, azygous and thoracic duct

Question 13

What passes throughout the oesophageal opening? At what level is this?

Answer 13

T10

Oesophagus, vagal trunks, oesophageal branches of the left gastric vessels

Question 14

What passes through the vena caval opening? At what level is this?

Answer 14

T8

The vena cava, right phrenic nerve

Question 15

Where does the hemiazygous vein cross the diaphragm?

Answer 15

It passes through the left crus

Question 16

Where do the greater and lesser splanchnic nerves cross the diaphragm?

Answer 16

They pierce each crus

Question 17

Where does the sympathetic trunk cross the diaphragm?

Answer 17

Behind the medial arcuate ligament

Question 18

Where does the subcostal nerve and vessel cross the diaphragm?

Answer 18

Behind the lateral arcuate ligament

Question 19

Where does the left phrenic nerve cross the diaphragm?

Answer 19

It pierce the dome

Question 20

What passes between digitations of the diaphragm and transversus abdominus muscle?

Answer 20

The neruovascualr bundles of T7-11

Question 21

How do the superior epigastric vessels cross the diaphragm?

Answer 21

I don’t know

Question 22

What passes directly through the diaphragm????

Answer 22

Extraperitoneal lymph vessels pass directly ???

Question 23

List two diaphragmatic congenital herniae and their locations

Answer 23

Bochdaleck (back)

Morgagni (front)

Question 24

List two acquired diaphragmatic herniae

Answer 24

Sliding

Gliding

Question 25

Define a sliding diaphragmatic hernia

Answer 25

This is the commonest type. Arises from the phreno-oesophageal ligament becoming stretched and the junction rising up into the thorax

Question 26

Define a gliding diaphragmatic hernia

Answer 26

Para-oesophageal

Question 27

What is the blood supply to the diaphragm?

Answer 27

The right and left inferior phrenic arteries. Intercostal and subcostal arteries also supply the margin.

Question 28

What is the nerve supply to the diaphragm?

Answer 28

The phrenic nerve to each side. These fibres radiate out in three branches (M and S ???)

Question 29

During quiet respiration, what is inspiration due to the work of? What muscles are accessory?

Answer 29

The diaphragm, intercostal muscles adjacent to the sternum and the scalene muscles. Sternocleidomastoid and the external intercostal muscles are accessory

Question 30

How does expiration occur? What muscles assist?

Answer 30

Largely passive, but external oblique, internal oblique, and transversus abdominus can assist.

Question 31

What are the layers of the inner layer of thoracic muscles?

Answer 31

Subcustal, innermost intercostals, and transversus thoracis.