Cardiovascular 2 Flashcards
Give the dimensions of the heart
12 cm long
9 cm wide
6 cm thick
Weighs between 250 and 300 grams
Located in the middle mediastinum
What is the mediastinum?
The central compartment of the thoracic cavity
Extends from the sternum to the vertebra column, the first rib to the diaphragm, and between the lungs
What does the mediastinum contain?
The heart, the great vessels, trachea, esophagus, thymus, thoracic duct, phrenic nerve, cardiac nerves, lymph nodes
What is the pericardium?
A membrane that surrounds the heart and the root of the great vessels
The parietal and visceral layers of the pericardium are continuous at the root of the great vessels
What are the components of the pericardium ?
-fibrous: tough connective tissue, forms the outer layer
- serous: thin and contains two parts
- parietal layer: lines the inner surface of fibrous
- visceral layer(epicardium): adheres to the heart and forms its most intimate covering
What is pericardial cavity?
A narrow space between the visceral and parietal layers of the serous pericardium
- Contains a thin film of lubricating fluid
- Collection of excess fluid in the pericardial cavity is known as pericardial effusion
What are the 3 layers of the heart?
Endocardium, myocardium, and pericardium form the three layers of the wall
What does the heart consist of ?
- An apex
- A base or posterior surface
- Sternocostal or Anterior Surface
- Left pulmonary surface
- Right pulmonary surface
- Diaphragmatic or inferior surface
What are the surfaces of the heart?
Anterior surface: formed mainly by the right ventricle, some portions of the right atrium and left ventricle
Inferior surface: formed by both ventricles, mainly left ventricle
Base: formed mainly by the left atrium. Located at the level of the 2nd ICS
Left pulmonary surface: faces the left lung, formed mainly by the LV, and a portion of the left atrium
Right pulmonary surface: faces the right lung. Consists of the right atrium
Apex: formed by the tip of the LV,. Located in the 5th LICS in the MCL
What are the borders (margins) of the heart?
Right border: right atrium
Left border: left ventricle and left auricle
Inferior border: right ventricle and slightly left ventricle
Superior border: both atria
What are the heart chambers?
2 atria- right and left atrium
2 ventricles- right and left ventricles
What are the heart valves?
Semilunar valves:
- Have 3 cusps shaped like half-moons
- Aortic and Pulmonary valves
- Unlike the AV valves, are not attached to the chordae tendinae
Atrioventricular valves:
- Located between the atrium and ventricle
- Tricuspid and Mitrial valve
What is systole?
Ventricular contraction
What is diastole?
Diastole
What are the 3 steps of the cardiac cycle?
- Relaxation period
- Atrial systole
- Ventricular systole