What is the inner most layer of the heart?
ENDOCARDIUM
What are the layers of the heart?
( In order from inner - outer)
- Endocardium
- Myocardium
- Epicardium
- Pericardium (Parietal & Fibrous)
What is the name of the cells that make up the layer of the endocardium?
Endothelial
What is the function of the myocardium?
Enables the heart to contract
True or false: the myocardium is the thickest layer of the heart.
TRUE
What cells make up the myocardium?
- Cardiomyocytes
What do cardiomyocytes need to be rich in to enable the muscle to contract effectively?
Mitochondria
True or False: The epicardium adheres to the myocardium
True
What cells make up the epicardium?
Mesothelial cells
True or False: Nerves and blood vessels that supply the heart are found in the epicardium
True
What fluid is the pericardinal sack filled with and what is its function?
Pericardinal fluid
Its function is to reduce friction when the heart contracts.
What are the names of the three coronary arteries?
- RCA: Right Coronary Artery
- LAD: Left Anterior Descending
- LCX: Left Circumflex Artery
What is the role of the LAD?
Supplies oxygen rich blood to the myocardium, supplies nearly half of the blood supply to the heart.
Where does the LAD branch off from and what layer of the heart is it located in?
- The left coronary artery
- Located sub subepicardially within the anterior and inferior interventricular shock
Where does the LCX deliver blood to?
- Left atrium
- Side and back of the ventricle
- Sometimes SA node
Which main coronary artery does the LCX branch off?
Left coronary artery
Where does the RCA originate from
Side of the aorta
What is the sequence of the cardiac conduction system?
- SA node
- AV node
- Bundle of his ( left and right branches)
- Purkinje fibres
What are the specialised cells that make up the SA node?
Pacemaker cells
The rate the SA nodes generate impulses is influenced by two nervous systems, what are they?
- Sympathetic
- Parasympathetic
What is the role of the AV node and why is it necessary?
The AV node slows down the electrical impulses to 120 ms so that the atria have enough time to fully eject blood before ventricular systole
Where are the Purkinje fibres located?
- Subendocardial surface of the ventricular walls
What is the role of the Purkinje fibres?
To assist ventricular contraction
What is preload?
Initial stretching of the cardiac muscle fibres before contraction.
Determined by the volume of blood returning to the heart during diastole.
