Thorax 2 - Mediastinum

Question 1

Damage to the phrenic nerves can lead to referred pain where?

Answer 1

Shoulder tip

Question 2

Which serous pericardial layer is closer to the cardiac muscle: visceral or parietal?

Answer 2

Visceral

Question 3

Where does the oblique sinus lie?

Answer 3

Posterior to/behind the left atrium

Question 4

What is the oblique sinus?

Answer 4

Part of a potential space in the pericardium

Question 5

What is the average pressure of the pulmonary circulatory system?

Answer 5

12-16mmHg

Question 6

What is the average pressure of the systemic circulatory system?

Answer 6

70-120mmHg

Question 7

In the correct anatomical positioning of the heart, where do each of the chambers lie?

Answer 7

Left atrium is posterior
Right ventricle is anterior
Left ventricle is on the left
Right atrium is on the right

Question 8

What is the base of the pericardium fused to?

Answer 8

The diaphragm

Question 9

Where is the base of the heart?

Answer 9

The left atrium and therefore lies on the posterior surface

Question 10

Name the other two surfaces of the heart.

Answer 10

Sternocostal surface

Diaphragmatic surface

Question 11

What is the main vein that drains blood from the heart muscle

Answer 11

Coronary sinus

Question 12

What forms the apex of the heart?

Answer 12

Left ventricle - palpable in the 5th LEFT INTERCOSTAL SPACE, MID-CLAVICULAR LINE

Question 13

What structures surround the heart?

Answer 13

Lungs
Pleura
Phrenic nerves

Question 14

What structures lie posterior to the heart?

Answer 14

Oesophagus

Descending aorta

Question 15

Where are the phrenic nerves derived from?

Answer 15

Cervical nerves C3, 4, 5 (cervical plexus)

Question 16

Give some of the roles that the phrenic nerves perform.

Answer 16

Motor supply to the diaphragm
Sensory from mediastinal parietal pleura
Sensory from the pericardium
Sensory from the underlying peritoneum & central tendon of the diaphragm

Question 17

What is cardiac tamponade?

Answer 17

Compression of the cardiac muscle, due to fluid in the pericardium

Question 18

List the layers of the pericardium.

Answer 18

Outer most - fibrous pericardium

Inner most - serous pericardium, consisting of outer parietal and inner visceral layers

Question 19

Where does the oblique sinus lie in relation to the heart?

Answer 19

Posterior to the heart (it is a potential space)

Question 20

Where does the transverse sinus lie?

Answer 20

Between the great arteries and veins, separating them

Question 21

How does the transverse sinus form in embryological development?

Answer 21

As the heart loops round ventrally, a space is surrounded/enclosed by the pericardium folds between the great vessels

Question 22

Considering where the oblique sinus lies in relation to the heart, which chamber would it border?

Answer 22

Left atrium

Question 23

Where do the great vessels lie in relation to the transverse sinus?

Answer 23

Aorta & Pulmonary Trunk lie anterior

SVC lies posterior

Question 24

List the borders of the heart.

Answer 24

2nd left cc
5th left interspace, mid clavicular line
6th right cc
3rd right cc

Question 25

Which spinal nerves do the phrenic nerves arise from?

Answer 25

C3,4,5

Question 26

To which structure do the phrenic nerves give motor supply?

Answer 26

Diaphragm

Question 27

To which structures do the phrenic nerves receive sensory supply?

Answer 27

Mediastinal parietal pleura Pericardium Central tendon of diaphragm Underlying peritoneum

Question 28

From which spinal nerves do the supraclavicular nerves arise?

Answer 28

C3,4

Question 29

Which dermatome does the lateral supraclavicular nerve supply?

Answer 29

C4 dermatome - skin over the shoulder

Question 30

Where is the location of referred pain in the pericardium?

Answer 30

Shoulder tip