Thorax 2 - Mediastinum Flashcards
Damage to the phrenic nerves can lead to referred pain where?
Shoulder tip
Which serous pericardial layer is closer to the cardiac muscle: visceral or parietal?
Visceral
Where does the oblique sinus lie?
Posterior to/behind the left atrium
What is the oblique sinus?
Part of a potential space in the pericardium
What is the average pressure of the pulmonary circulatory system?
12-16mmHg
What is the average pressure of the systemic circulatory system?
70-120mmHg
In the correct anatomical positioning of the heart, where do each of the chambers lie?
Left atrium is posterior
Right ventricle is anterior
Left ventricle is on the left
Right atrium is on the right
What is the base of the pericardium fused to?
The diaphragm
Where is the base of the heart?
The left atrium and therefore lies on the posterior surface
Name the other two surfaces of the heart.
Sternocostal surface
Diaphragmatic surface
What is the main vein that drains blood from the heart muscle
Coronary sinus
What forms the apex of the heart?
Left ventricle - palpable in the 5th LEFT INTERCOSTAL SPACE, MID-CLAVICULAR LINE
What structures surround the heart?
Lungs
Pleura
Phrenic nerves
What structures lie posterior to the heart?
Oesophagus
Descending aorta
Where are the phrenic nerves derived from?
Cervical nerves C3, 4, 5 (cervical plexus)
Give some of the roles that the phrenic nerves perform.
Motor supply to the diaphragm
Sensory from mediastinal parietal pleura
Sensory from the pericardium
Sensory from the underlying peritoneum & central tendon of the diaphragm
What is cardiac tamponade?
Compression of the cardiac muscle, due to fluid in the pericardium
List the layers of the pericardium.
Outer most - fibrous pericardium
Inner most - serous pericardium, consisting of outer parietal and inner visceral layers
Where does the oblique sinus lie in relation to the heart?
Posterior to the heart (it is a potential space)
Where does the transverse sinus lie?
Between the great arteries and veins, separating them
How does the transverse sinus form in embryological development?
As the heart loops round ventrally, a space is surrounded/enclosed by the pericardium folds between the great vessels
Considering where the oblique sinus lies in relation to the heart, which chamber would it border?
Left atrium
Where do the great vessels lie in relation to the transverse sinus?
Aorta & Pulmonary Trunk lie anterior
SVC lies posterior
List the borders of the heart.
2nd left cc
5th left interspace, mid clavicular line
6th right cc
3rd right cc
Which spinal nerves do the phrenic nerves arise from?
C3,4,5
To which structure do the phrenic nerves give motor supply?
Diaphragm
To which structures do the phrenic nerves receive sensory supply?
Mediastinal parietal pleura
Pericardium
Central tendon of diaphragm
Underlying peritoneum
From which spinal nerves do the supraclavicular nerves arise?
C3,4
Which dermatome does the lateral supraclavicular nerve supply?
C4 dermatome - skin over the shoulder
Where is the location of referred pain in the pericardium?
Shoulder tip
