Cardiac Anatomy Flashcards
How much does the heart weight and how much blood does it move everyday
- Weights roughly 250g-300g
- 700-900ml of blood moved everyday
What are the 3 layers of the hearts wall and describe them
- Epicardium: outer most layer (thin serous membrane) part of the Visceral membrane of the paricardium
- Endocardium innermost layer of the heart wall, smooth layer made up of connective tissue
- Myocardium muscle layer of the cardiac wall (found between epicardium and endocardium
What is the Pericardium
- Fibrous sac that surrounds the heart
- contains Serous fluid rougly 30ml
- The fluid lubricates the heart to prevent friction during contractions
- The sac has very little stretch and excess build of of fluids (pericardial tamponade) impeads the hearts ability to Pump effectivly
- it has 2 surfaces
- Outer parietal layer: outer layer of the sac
- the inferior portion attaches to the diaphragm
- Inner visceral layer: inner layer of the sac creates the Epicardium layer of the heart wall
What are properties of cardiac cells (myocardium)
- Increase contractile force when stretched
- Autonomicity: abilty to generate own electrical impulses w/out nervous system
- contain excess mitochondrai due to high demand for constant energy
What are the chambers of the heart
4 Chambers in the heart:
* Left atrium: Recieves oxygenated blood from pulmonary veins
* Right atrium: recieves deoxygentated blood from the systemic veins
* Left ventricle: Sends blood throughout the systemic vascular system
* Right ventricle: sends blood throughout the pulmonary artery
What are the valves that seperate the artium and ventricles called
Atrioventricular valves
* Tricuspid valve: Seperates the right artia from the right ventricle
* Mitral valve: Seperates the left atria from the left ventricle
What are the valves that seperate the ventricles from the arteries
Semilunar valves
* Pulmonic valve: Seperates the right venticle from the pulmonary artery
* Aortic valve: Seperates the left ventricle from the Aorta
These prevent backflow from the arteries into the ventricles
What are the Intercalated discs
gap junctions that link adjacent cardiac muscles so that electrical impulses can travel between cells and causes to contract almost simultaneously
What are Chordae tendineae
They are like guide wires that attach to the papillary muscles and keep the valves from inverting during contraction
This prevents backflow from occuring and backflow into the atrium would occur if this function isnt working
What is the Interventricular septum and what are its 2 parts
Triangle portion that seperates the 2 ventricles: consits of a muscular and membranous portion
* Muscular portion: recieves blood from the left coronary artery
* has 3 main portions : inlet, trabecular and infundibular septum
* located at the lower portion of the heart
* Membraouns portion: recieves blood from the right corornary artery
* located in the upper portion of the heart
What are Coronary arteries
Arteries that carry oxygenated blood to the heart, these branch off of the aorta
What are the 2 main Coronary artiers and what do they supply
- Left coronary artery: subdivides into the left anterior descending and the circumflex coronary artery
- Supplies the Left ventricle, interventricular septum and parts of the right ventricle
- Right coronary artery: Supplies the right atria, right ventricle and parts of the left ventricle
What is the Coronary sulcus
-It is a grove that the coronary arteries and main coronary vein use to cross the heart
-It seperates the atria from the ventricles
What is the Coronary Sinus
-Is a large vessel located in the posterior portion of the coronary sulcus and will eventually join and become the right atrium
- venous blood empties into the the coronary sinus
How does blood flow through the heart?
- The blood oxygenated blood empties into the left atria via the Pulmonary veins and deoxygenated blood empties into the right atria via the inferior and superior venae cavae
- The Atrium fill passivly through venous pressure allowing blood to flow through the AV valves into the ventricles
- The Atrial kick occurs where the Atrium contracts filling the rest of the ventricle
- The pressure in the ventricle increases surpassing the pressure from the atrium causing the AV valves to close
- The 2 ventricles undergo ventricular systole which causes a pressure increase inside the venticles
- when the pressure surpasses that of the arteries the semilunar valves open
- The left ventricle empties through the aortic valve and into the aorta to circulate the body
- the right ventricle empties through the pulmonic valve and into the pulmonary artery to head to the lungs to be exchanged for oxygenated blood
