Circulatory System (Hearts) Flashcards
What is the function of the circulatory system? (2)
- distributes oxygen and nutrients to entire body
- picks up waste materials by cells to be eliminated by other systems (respiratory, urinary systems)
What does the circulatory system include?
heart and blood vessels
What is the mediastinum bounded by?
bounded anteriorly by sternum and costal cartilages, laterally by lungs, and posteriorly by bodies of thoracic vertebrae
What does the mediastinum contain?
heart and its large vessels
esophagus
trachea
thoracic aorta
What are the 2 parts of the mediastinum?
What are they divided by?
superior and inferior parts
divided by transverse imaginary plane passing through sternal angle anteriorly, and intervertebral disc between vertebrae TIV and TV posteriorly
What are the 3 parts of the inferior mediastinum?
middle mediastinum
anterior mediastinum
posterior mediastinum
Inferior Mediastinum
What does the middle mediastinum contain?
- heart and its pericardium (membrane)
- ascending aorta, pulmonary trunk, and pulmonary veins
- right and left phrenic nerves
main bronchi
Inferior Mediastinum
Where is the anterior mediastinum?
between sternum and pericardium
Inferior Mediastinum
What does the anterior mediastinum contain?
thymus gland
Inferior Mediastinum
Where is the posterior mediastinum?
between pericardium, and bodies of vertebrae TV-TXII
Inferior Mediastinum
What does the posterior mediastinum contain?
- descending aorta, azygus, and hemiazygus veins
- right and left vagus nerves
- sympathetic chains (trunks) and splanchnic nerves
- thoracic duct and esophagus
What does the superior mediastinum contain?
- arch of aorta and its branches
- right and left brachiocephalic veins, inferior part of superior vena cava, and end of azygus vein
- right and left phrenic and vagus nerves
- trachea, esophagus, thymus gland, and thoracic duct
What is the heart?
muscular conical pump
Where is the heart located?
middle mediastinum
Describe the path of blood circulation from the body.
- right atrium receives deoxygenated blood from entire body, and passes it to right ventricle
- right ventricle pumps blood to lungs (pulmonary circuit)
- left atrium receives oxygenated blood from lungs, and passes it to left ventricle
- left ventricle pumps blood throughout body (systemic circuit)
Surface Anatomy of Heart
What are the 4 corners of the quadrangle that demarcates the heart image on the chest?
- upper left corner: in left 2nd intercostal space, 1 inch away from midline
- upper right corner: at right 3rd costal cartilage, 1 inch away from midline
- lower right corner: at right 6th costal cartilage, 1 inch away from midline
- lower left corner: in left 5th intercostal space, 3-4 inches away from midline
External Features of Heart
What are the 4 main external features?
- heart sulci
- heart surfaces
- heart base
- heart apex
External Features of Heart - Sulci
What are the 3 main sulci?
- coronary sulcus
- anterior interventricular sulcus
- posterior interventricular sulcus
External Features of Heart - Sulci
What does the coronary sulcus do?
encircles heart and separates atria from ventricles
External Features of Heart - Sulci
Where are the anterior and posterior interventricular sulci?
between ventricles on anterior and inferior surfaces
External Features of Heart - Surfaces
What are the 4 surfaces?
- anterior (sternocostal) surface
- inferior (diaphragmatic) surface
- left pulmonary surface
- right pulmonary surface
External Features of Heart - Surfaces
Where is the anterior (sternocostal) surface?
What does it consist of?
related to sternum and 2nd-6th costal cartilages
consists of right ventricle and parts of right atrium and left ventricle
External Features of Heart - Surfaces
Where is the inferior (diaphragmatic) surface?
What does it consist of?
leaning on diaphragm, has posterior interventricular sulcus
consists of left ventricle, and small part of right ventricle
External Features of Heart - Surfaces
Where is the left pulmonary surface?
What does it consist of?
related to left lungs
consists of left ventricle, and portion of left atrium
External Features of Heart - Surfaces
Where is the right pulmonary surface?
What does it consist of?
related to right lung
consists of right atrium
External Features of Heart - Base
What is the heart base formed by?
What direction does it face?
mainly formed by left atrium and small portion of right atrium
faces posteriorly