circulatory system Flashcards
mediastinum
middle chest
- contains heart, its large vessels
- esophagus
- trachea
- thoracic aorta
mediastinum bounded anteriorly by?
sternum and costal cartilages
mediastinum bounded laterally by
lungs
mediastinum bounded posteriorly by?
bodies of thoracic vertebrae
mediastinum divided into 2 parts
- superior
- inferior
- separated by transverse imaginary plane passing through sternal angle anteriorly and intervertebral disc btw vertebrae TIV and TV posteriorly
inferior mediastinum divided into 3 parts
- middle
- anterior
- posterior
anterior part of inferior mediastinum
- located btw sternum and pericardium
middle part of inferior mediastinum
- occupied by heart and surrounding membranes (pericadium)
posterior part of inferior mediastinum
- btw pericardium and bodies of vertebrae TV to TXII
superior mediastinum contains:
- arch of aorta and its branches
- right and left brachiocephalic veins, inferior part of superior vena cava, and end of azygus vein
anterior mediastinum contains:
- thymus gland
middle mediastinum contains:
- heart and pericardium
- ascending aorta, pulmonary trunk, pulmonary veins
- right and left phrenic nerves
- main bronchii
posterior mediastinum contains:
- descending aorta, azygus, hemiazygous vein
- right and left vagus nerve
- sympathetic chains (trunk) and splanchnic nerve
- thoracic duct and esophagus
heart
- muscular conical pump located in the middle mediastinum
pulmonary circulation
- right atrium receives dexoygentated blood, pass to right ventricle to lungs
systemic circulation
- left atrium receives oxygenated blood, pass to left ventricle, to body
surface anatomy of heart: 4 corners
- upper left corner
- upper right corner
- lower right corner
- lower left corner
upper left corner
- left 2nd intercostal space
- 1 inch away from midline
upper right corner
- right 3rd costal cartilage
- 1 inch away from midline
lower right corner
- right 6 th costal cartilage
- 1 inch away from midline
lower left corner
- left 5th intercostal space
- 3-4 inches away from midline
external features of heart
- heart sulci
- heart surfaces
- heart borders
- heart base
- heart apex
heart sulci: 3 main sulci
- coronary sulcus
- anterior sulcus
- posterior sulcus
coronary sulcus
- encircles heart
- separate atria from ventircles
anterior and posterior interventricular sulci
- located between ventircles on anterior and inferior surfaces
heart surfaces: 4 surfaces
- anterior (sternocostal) surface
- inferior (diaphragmatic) surface
- left pulmonary surface
- right pulmonary surface
anterior (sternocostal) surface
- related to sternum and 2nd to 6th costal cartilages
- consists of right ventricle and parts of right atrium and left ventricle
inferior (diaphragmatic) surface
- leaning on diaphragm
- posterior interventricular sulcus located here
- consists of left ventricle and small part of right ventricle
left pulmonary surface
- related to left lung
- consists of left ventricle and portion of left atrium
right pulmonary surface
- related to right lung
- consists of right atrium
heart borders: 4 borders
- superior border
- right border
- left border
- inferior border
superior border
- formed by right and left atria and auricles
right border
- form by right atrium
left border
- formed mainly by left ventricle
- partly by left auricle
inferior border
- separates anterior surface from inferior surface
- mainly formed by right ventricle
- small portion of left ventricle
heart base
- faces posteriorly
- mainly formed by left atrium
- small portion of right atrium
heart apex
- formed by left ventircle
- directed anteriorly, inferiorly and to the left
heart chambers: 4 chambers
- right atrium
- right ventricle
- left atrium
- left ventricle
right atrium
- receives venous blood from SVC, IVC, coronary sinus
- pectinate muscle lines anterior and extends to right auricle
fossa ovalis in right atrium
- impression in interatrial septum
- remnant of embryonic foramen ovalis that used to connect right atrium and left atrium
connection btw left atrium and ventricle
- right atrioventricular opening
- guarded by tricuspid valve
right ventricle
- walls of right ventricle thicker and carry trabeculae carneae (muscular ridges)
group of trabeculae carneae
- papillary muscles
- arise from walls of ventricle
- insert to leaflets of tricuspid valve
chorda tendinae
- attaches papillary muscles to tricuspid valve
pulmonary artery
- arise from supeior part of right ventricle
- pulmonary valve prevent blood flow back to ventricle
right ventricle and left ventricle separated by ?
- interventricular septum