L3: pericardium and external heart Flashcards
useful landmarks for the heart
heart is behind ribs 2-5
2-5th intercostal spaces
Apex located on midclavicular line in the 5th intercostal space ( apical pulse- indicates whether the heart is in the correct orientation)
layers of the pericardium
Fibrous pericardium- most outer layer, connected to the diaphragm
Serous pericardium:
-Parietal: lines the fibrous pericardium
-Visceral pericardium( also called epicardium)
Create pericardial cavity. Filled with serous/ pericardial fluid.
what nerve supplies the pericardium?
What layers does this nerve supply?
phrenic nerve( C3, C4, C5)
Runs between fibrous pericardium and parietal pleura.
Innervates parietal pleura, fibrous pericardium and parietal pericardium
BUT not the visceral pericardium
Irritation of the pericardium layers innervated by the phrenic nerve: referred pain to where?
shoulder and outer arm
C3,4, 5 dermatomes
nerve supply to visceral pericardium
sympathetic chain nerves
(T1-T4)
heart attack: heart wall is experiencing pain: visceral pericardium> sympathetic nerves> referred pain to T1-T4: inside of the arm and chest
how to find out where the problem is in the pericardium with referred pain?
! Parietal and visceral pericardium have different nerve supply( one is associated with the heart wall and the other with fibrous pericardium)
Irritation of the visceral pericardium-> dermatomes for T1-T4( T1- inside of the arm, T2-T4 on the chest). Heart attack and heart wall is experiencing pain-> referred pain on the chest and radiating down the inside of the arm.
Pericarditis- inflammation inside the pericardial cavity(both visceral and parietal pericardium are affected)-> stimulating both phrenic nerve and sympathetic chain nerves-> pain in both dermatomes: shoulder, outside of the arm, inside of the arm and the chest.
If just the outside of the shoulder or outside of the arm- likely to be on the other side of the parietal pleura-> lung in origin.
*Outside/ lateral side of the parietal pleura is innervated by intercostals.
If pain just on the chest and inside of the arm-> suspect it’s the heart wall(pain from visceral peritoneum only)-more dangerous and life-threatening
what is the most common way of aspirating fluid from the pericardial space
apical drain
or come from underneath the diaphragm( patient lies on their back and draws the belly in can come in under)
e.g. cardiac temponade
what is the clinical significance of transverse pericardial sinus?
during heart surgery provides access to clamp off the artery and the veins
what is the clinical significance of oblique pericardial sinus?
if patient is lying down fluid can accumulate there and can be seen on X-ray
differences between orientation of the pericardium and the heart
The orientation and terminology of the pericardium can be slightly different to the heart
*Base= broadest part
Base of pericardium: comes in contact with the diaphragm
*Apex= narrow part
Apex- where the fibrous pericardium attaches onto the vessels. And here the serous membrane reflects back on itself
Heart:
Base is more towards the posterior side of the body. Broadest area. “Where the vessels enter and exit”.
Apex of the heart points to the left: inferiorly and anteriorly. Narrow part
what forms the borders of the heart?
Right border: right atrium
Left border: left ventricle and left auricle
inferior border/margin:
right ventricle
what is the importance of heart borders?
x-rays
can pick up abnoramalities
arteries or veins seen better on x-ray?
arteries
what is the landmark that divides the left ventricle externally from the right ventricle ?
anterior interventricular sulcus/groove
cardiac arteries and veins run in it
3 important grooves/sulci
of the heart
anterior interventricular groove(coronary sulcus)
posterior interventricular groove
atrioventricular groove
main coronary venous structure
coronary sinus
