What size is the heart?
Fist sized
What is the heart protected by and is double layered?
Pericardium - double sac
What are the two layers of the pericardium?
What is the function of the Fibrous layer of the pericardium?
Under certain physiological conditions - you could have the risk of overstretching/overfilling.
If that happens to the heart - it will reduce the functionality of the pumping of the heart.
What is the function of the serous layer of the pericardium?
It has two layers itself
Serous Pericardium
fluid separates two more layers
in between the two layers is fluid that protects from friction.
2 layers are:
1. Parietal layer
2. Visceral layer
Parietal Layer of the Serous Pericardium
Visceral Layer of the Serous Pericardium
AKA epicardium
Internal layer - on surface of the heart
Two layers of the Serous Pericardium
Pericardial Fluid
Having two sticky layers (parietal & Visceral) of the membrane
1. the fluid is going to help the two layers slide past each other
2. to avoid friction
3. or inflammation
Pericarditis
Negative impact associated with inflammation and infection of the pericardial layers.
That could be damaging because may build-up of fluids, irritations, inflammation on the heart is going to negatively impact its ability to act as an appropriate pump
Name the three layers of the heart:
Epicardium
Myocardium
Why & where does the myocardium have variable thickness?
Variable thickness Where?
1. Atriums are not very thick
2. Right ventricle is a bit thicker
3. Left ventricle is very thick
Variable thickness WHY?
1. to allow for the pumping of the blood to all the various locations that it needs to go
2. needing different amounts of muscle strength to pump blood out to the lungs vs the systemic circuit
Endocardium
Blood vessels in body all have squamous epithelium and is connected to your heart.
Endocarditis
Inflammation in the heart (endocardium)
Possible causes of endocarditis
Endocarditis could lead to
Valve Damage
the pumping of the heart would be impaired
Emboli
could end up with traveling blood clots which could lodge in:
1. the heart - causing a heart attack
2. lungs - causing a pulmonary embolism and pulmonary edema
3. Brain - causing a stroke
Myocardium has a unique set of features within the ventricles:
Papillary Muscles
Function - to help hold the ventricular valves in place and keep them from inverting.
They hold the chordae tendineae which are attached to the AV valves and anchored by the papillary muscles to the myocardium.
Ensuring that the valves do not get pushed backwards into the atria as the ventricles contract
Heart Features
Another name for bicuspid valve
Mitral
How many cusps do the tricuspid have?
Right side = 3 cusps
How many cusps does the bicuspid (mitral) valve have?
Left side = 2 cusps