Week 1: Module 1 Pt. 1 Flashcards
(23 cards)
What is the pulmonary circuit?
Right side of the heart, carries deoxygenated blood towards lungs for gas exchange and then back to the heart.
What is the systemic circuit?
Left side of the heart, carries oxygenated blood to all tissues and then back to the heart.
Where is the heart located?
In the mediastinum, between the 2nd and 5th ribs between the lungs.
What are the 3 main layers of the Pericardium?
- Fibrous pericardium: anchoring and structural support.
- Serous Pericardium: connects fibrous pericardium to Epicardium.
- Pericardial cavity: contains serous fluid for lubrication.
What’s are the main layers of the heart wall?
- Epicardium: visceral layer of pericardium.
- Myocardium: muscle layer of the heart, bulk of heart.
- Endocardium: lining of chambers and valves. (Epithelium cells are similar to endothelium of blood vessels)
What’s the internal heart structure like?
4 chambers separated by:
- 2 atrium: separated by a thin interatrial septum.
- 2 ventricles: separated by a thick muscular inter-ventricular septum.
What’s the external heart structure like?
- Coronary sulcus: (atrioventricular groove) encircles the heart.
- also has thin walls called auricles to increase blood flow. - Inter-ventricular sulcus: separates left and right.
What are sulcus/sulci?
Indentations on the surface of the heart.
What does both sulcui contain?
Coronary vessels
What are atria and ventricles separated by?
Atrioventricular valves (AV):
1. Tricuspid
2. Bicuspid/mitral valves.
What do valves do?
They control blood flow and prevent back flow.
What are associated AV structures?
Papillary muscles that are connected to AV valves via Chordae Tendinae to keep valves tightly shut during ventricular contractions.
What is the difference between diastole and systole?
Diastole: Ventricular filling; blood flow is driven by pressure gradient (relaxation)
Systole: Ventricular contraction; driven by inter-ventricular pressure.
Why is the myocardium in the left ventricle thicker than the right ventricle?
The systemic circuit encounters more resistance in long pathways.
What does an artery blockage caused by arteriosclerosis cause?
Muscle death. Myocardial infarction.
How is blood and nutrients delivered to the heart?
Through coronary circulation. By the right and left coronary arteries.
What are the main right coronary arteries?
- Posterior inter-ventricular artery: supplies right and left ventricle.
- Right marginal artery: supplies right ventricle.
What are the main left coronary arteries?
- Circumflex artery: supplies right and left ventricle.
- Anterior inter-ventricular artery: left ventricle.
What vein is known as the “widow maker” and why?
Anterior inter-ventricular artery due to high death caused by infarction.
How is venous blood drained from the heart?
- Small cardiac vein: drains right ventricle.
- Middle cardiac vein: drains posterior right and left ventricle.
- Great cardiac vein: runs parallel to LAD and drains into coronary sinus.
- Coronary sinus: drains into right atrium along with SVC and IVC.
What is the foramen ovale?
In fetal development, it is a hole in the interatrial septum to allow blood to bypass pulmonary circulation as fetuses do not have lungs.
What is the ductus arteriosis?
In feral development, it bridges together the pulmonary trunk and descending aorta to allow blood to be pumped to the placenta and not the lungs (babies don’t have lungs yet).
What are the main structures of cardiomyocytes?
- Desmosomes: holds cells together.
- Gap junctions: allows ions to flow through cells.
Together this makes a functional syncytium.
