5. The Heart Flashcards
What is the pericardium?
The outermost layer of the heart
What is the pericardium composed of?
Layer of mesothelial cells resting on thin layer fibrous connective tissues
Visceral and parietal
What is the epicardium?
The adipose connective tissue, vessels and merves between the pericardium and myocardium
What is the myocardium?
The thickest layer of the heart
Describe the myocardium. (4)
- Striated
- Central nuclei
- Branching
- Intercalated discs
What do intercalated discs do?
Connect adjacent cardiac myocytes
What do intercalated discs contain?
- Gap junctions
- Adhering junctions
- Desmosomes
What is endomysium?
Loose fibrous connective tissue between the muscle fibres
Describe atrial myocytes.
They are smaller than those in the ventricles and contain perinuclear neuroendocrine granules (atrial natriuretic peptide)
What are the 4 main components of the conducting systems?
- Sinoatrial node
- Atrioventricular node
- Budle of His
- Purkinje fibres
What is the endocardium?
The innermost layer of the heart composed of a thin layer of fibrous connective tissue
Describe valve histology.
Covered by an endothelium and attach to central fibrous body, are specialised extensions of endocardium
What are the 3 layers of valves?
- Fibrosa
- Spongiosa
- Ventricularis
What are the 4 layers of the heart?
- Pericardium
- Epicardium
- Myocardium
- Endocardium
