valves Flashcards
what are the three cusps of the tricuspid valve?
anterior, septal, and posterior
what are the two cusps of the mitral valve?
anterior and posterior
where is the pulmonary valve?
at the apex of the conus arteriosus
what is the structure of the pulmonary valve
3 semilunar valve cusps (anterior, right, left)
what is the structure of the aortic valve
3 cusps
From where is blood supply to heart derived?
From the right and left coronary arteries. The main branches of these arteries lie in the inter-ventricular and atrio-ventricular grooves
Describe the right coronary artery and its branches.
The right coronary artery arises from the ANTERIOR aortic sinus of ascending aorta, runs forward between the pulmonary trunk and right atrium, descends in the right atrio-ventricular groove and gives branches to the right atrium and right ventricle; anastomoses with the left coronary artery at the inferior border of the heart. Gives off two branches:
1. Marginal branch: supplies right ventricle
Posterior interventricular branch: supplies both ventricles
Describe the left coronary artery and its branches.
The left coronary artery is LARGER than the right. It arises from the LEFT POSTERIOR aortic sinus of ascending aorta, runs forward between the pulmonary trunk and the left auricle, enters atrioventricular groove and divides into two branches:
1. Anterior interventricular branch – supplies ANTERIOR aspect of both ventricles, and passes around the apex of the heart to anastamose with the posterior interventricular branch of the right coronary artery.
Circumflex branch – follows the atrioventricular groove and ultimately anastomoses with the right coronary artery; supplies the left atrium and ventricle
At rest, average beats per minute?
70-90 beats per minute
What three things make up conduction system of heart? Describe them.
The following three things make up the conduction system of the heart:
- Sino-atrial node – this is the pacemaker of the heart. It is located at the upper part of the crista terminalis near the opening of the superior vena cava into the right atrium. Contractions are initiated here, spread through atrial myocardium to reach the AV node.
- Atrio-ventricular node – this is in the lower part of atrial septum, immediately superior to the attachment of the septal cusp of the tricuspid valve. Its impulses project to the ventricles via the Bundle of His.
- Atrioventricular bundle (of His) – specialized conducting muscle fibers (purkinje fibers) divide at the upper border of the muscular part of the septum into right and left branches to supply the ventricles.
Where is the sympathetic innervation of heart sourced?
- Preganglionic in lateral horn of spinal cord T1-T6
2. Postganglionic in cervical and upper thoracic ganglia
Where is the parasympathetic innervation of heart sourced?
- Preganglionic in nuclei of Vagus nerve
2. Postganglionic in cardiac plexus and walls of heart
How does blood drain from the heart?
2/3 of the venous drainage of heart is via veins that accompany the coronary arteries. They empty into the coronary sinus, then into the right atrium (deoxygenated blood).
The rest of the blood drains via venae cordis minimae (small veins) directly into the cardiac chambers
What is the coronary sinus?
The coronary sinus lies in the posterior atrioventricular groove and is a continuation of a great cardiac vein. It opens into the right atrium near the mouth of the inferior vena cava.
What three cardiac veins drain into the coronary sinus? Where are they located and what do they accompany? What do they drain?
The three veins that drain into the coronary sinus are:
1. Great cardiac vein – accompanies LAD. Drains both ventricles, part of left atrium.
2. Middle cardiac vein – in posterior interventricular groove. Drains posterior ventricular surface.
Small cardiac vein – accompanies Marginal Artery. Drains posterior right atrium/ventricle
