Cardiology anatomy Flashcards
What are the 2 layers of the pericardium?
Fibrous and serous
What is the fibrous pericardium continuous with?
Central tendon of the diaphragm
Which layer of the pericardium is the tough, external layer?
Fibrous pericardium
What is the purpose of the fibrous pericardium being non-distensible?
Rigid structure prevents rapid over-filling of the heart.
What are the 2 subdivisions of the serous pericardium?
Outer parietal layer and inner visceral layer
What is the internal visceral layer also known as?
Epicardium
The outer parietal layer lines what?
The internal surface of the fibrous pericardium
The inner visceral layer forms what?
The outer layer of the heart
Where is the pericardial cavity?
Between the outer parietal and inner visceral layers of the serous cavity
What is the function of the serous fluid within the pericardial cavity?
Minimises friction generated by the heart as it contracts.
What are the 4 main functions of the pericardium?
Fixes the heart
Prevents overfilling
Lubrication
Protection from infection
What is the innervation of the pericardium?
C3 - C5 (why you get shoulder pain with pericarditis)
What is the order of the layers of the pericardium from most external to most internal?
Fibrous layer
Parietal layer
Serous fluid
Visceral layer
Where is the SAN located?
Upper wall of right atrium at the junction where the superior vena cava enters.
What does the sympathetic nervous system do to the firing rate of the SAN?
Increases firing rate = increased HR
What does the parasympathetic nervous system do to the firing rate of the SAN?
Decreases firing rate = decreased HR
Where is the AVN located?
Within AV septum, near the opening of the coronary sinus
Why does the AVN delay impulses by ~120miliseconds?
To ensure the atria have enough time to fully eject blood into the ventricles before ventricular systole