Lecture 7 - Structure of the Heart Flashcards
What is the sac-like covering of the heart called, and what layers is it split into?
Pericardium - the outer Fibrous Pericardium, and the inner Serous Pericardium (which itself consists of Outer Parietal Layer and Inner Visceral Layer)
What are the 3 main layers of the heart wall and what do they each consist of?
Endocardium (inner) - endothelium
Myocardium (middle) - cardiac muscle
Epicardium (outer) - visceral pericardium
What are the names of the two types of “ridges” seen inside the heart
Trabeculae carnae - rough ridges formed by muscle fibres in the ventricles
Pectinate Muscles – ridges in the atria (formed by bundles of muscle fibres)
What is the fibrous skeleton of the heart?
Bands of fibrous connective tissue between the atria and ventricles, and encircling the pulmonary arteries and aorta.
What are the functions of the fibrous skeleton?
Electrically separates the atria and ventricles (slows down impulses between them), also the valves are suspended from the fibrous skeleton.
What is the name of the muscles that contract to prevent eversion of the atrioventricular valves?
Papillary muscles
What arteries do the Left and Right Coronary Arteries split into?
LCA -> Left Anterior Descending (AKA anterior interventricular) and Circumflex (which wraps around the back of the heart)
RCA -> Marginal Artery and Posterior Interventricular
What are the three bypasses in foetal circulation?
1 - bypasses right ventricle and pulmonary system (Foramen ovule)
2 - bypasses pulmonary system and left side of heart (Ductus arteriosus)
3 - bypasses liver (Ductus venosus)
What 3 changes to the foetal circulatory system occur after birth?
- Foramen ovule closes -> fossa ovalis
- Ductus arteriosus is constricted -> Ligamentum arteriosum
- Ductus venosus fibroses -> Ligamentum venosum
