External and Internal Heart Flashcards
What is the CVS made up of?
Heart - pump, blood vessels and lymphatics
What are the 2 main circulations of the CVS?
Pulmonary and Systemic
Also can include the hepatic portal circulation for lymphatic system
What area of the mediastinum does the heart lie?
Middle mediastinum
Explain the mediastinum
Between the left and right pleura
It extends from the sternum in front of the vertebral column behind and contains all the thoracic structures except lungs and pleura
What are the anterior anatomical relations of the heart?
Sternum and costal cartridges of ribs 4-7
T4 sternal angle
What are the posterior, lateral and inferior anatomical relations of the heart?
Posterior - oesophagus and descending aorta
Lateral - Pleura and phrenic nerve
Inferior - Central tendon of diaphragm
Explain the heart borders
Right border is RA
Left border is LV
Superior border is auricles and great vessels
Inferior border us RA, RV and LV
What is the anterior/ sternocostal surface?
1/3 of RA and 2/3 RV and LV
What is the inferior (diaphragmatic) surface?
RV and LV
What is the posterior surface (base)?
LA
Where does the heart lie anteriorly compared to vertebrae?
T5-T8
Where is the apex of the heart?
5th left intercostal space - midclavicular line
LV
What is the border of the heart anteriorly compared to ribs?
Upper right cc rib 3
Upper left rib 2
Lower right cc rib 6
Apex
What is the pericardium made up of?
2 pericardia - fibrous and serous
Explain the fibrous layer of pericardium
Dense connective tissue sac
Outermost layer
Explain the serous layers of the pericardium?
Outer parietal layer and inner visceral layer (epicardium)
Describe the pericardial cavity
Between parietal and visceral layers and filled with fluid
What branches does the right coronary artery give off?
Right marginal artery
Posterior intraventricular artery
What branches does the left coronary artery give off?
Left anterior descending artery
Circumflex artery
What are the anastomoses of the coronary arteries?
Anterior and posterior descending
Circumflex and right coronary artery
What are the 2 major sulci that contain the branches of coronary arteries?
Atrioventricular sulcus
Interventricular sulcus
Where does right coronary artery supply?
Supplies the right atrium and right ventricle
Where does the right marginal artery supply?
Right ventricle and apex
Where does left marginal artery supply?
Left ventricle
Where does the left anterior descending artery supply?
Right ventricle, left ventricle and interventricular septum
Where does right marginal artery supply?
Left atrium and left ventricle
What are the main veins of the heart wall?
Great cardiac vein
Middle cardiac vein
Small cardiac vein
All drain to coronary sinus which lies beside circumflex artery
Where does the coronary sinus drain to?
Right atrium
Anterior cardiac veins drain directly into RA
What are the nerves to the heart?
Phrenic nerve
Vegus nerve
Sympathetic nerve
What is the intrinsic and extrinsic innervation of the heart?
Intrinsic - purkinje cells in SA node
Extrinsic - external autonomic nerves
What does the phrenic nerve innervate?
Innervates the fibrous pericardium and parietal layer of serous pericardium
Carries pain sensation
What does the vegus nerve innervate?
Is parasympathetic
Innervates the heart myocardium and visceral layer of serous pericardium
Where do sympathetic nerves innervate?
T1-4
Innervate myocardium and visceral layer of serous myocardium - referred pain to inner surface of upper arm
What can be seen of the heart on a normal CXR?
Aortic arch
RA, RV and LV - apex of the heart
How are chambers positioned on transverse plane?
RV most anterior
LA most posterior
RA on most right and LV on most left
What are the main features of the right atrium?
Openings for IVC, SVC and coronary sinus
Interatrial septum
Fossa ovalis in interatrial septum
Musculi pectinate
Tricuspid valve
What are the main features of the right ventricle/
3 papillary muscles with chordae tendineae for the tricuspid valve
Trabeculae carneae, modulator band, opening for pulmonary trunk
Intrerventricular septum
What is the function of the trabeculae carneae?
Prevent suction that would occur with a flat surface and thus impair the hearts ability to pump efficiently
What are the main features of the left atrium?
Openings for pulmonary veins and Mitral (bicuspid) valve
Smooth walled, small chamber
Posterior superior against oesophagus
Forms the posterior surface of the heart
What are the main features of the left ventricle?
2 papillary muscles and chordae tendineae
Trabeculae carneae
Opening for the aorta, interventricular septum
Walls x3 thicker than left
Forms the apex of the heart
What is the intrinsic innervation of the heart?
Signals arise in SA node which stimulate atrium to contract and travels to AV node
After delay, then conducted to bundle of His and left and right bundles of branches to endocardium then ventricles then epicardium
What is the extrinsic innervation of the heat?
Vagus and sympathetic nerves T1-4 via cardiac plexuses
Where is the point of auscultation for mitral valve?
5th intercostal space, midclavicular line - apex beat
Where is the point of auscultation for the tricuspid valve?
4th left intercostal space on lower left of sternum
Where is the point of auscultation for the pulmonary valve?
2nd left intercostal space on left of upper sternum
Where is the point of auscultation for the aortic valve?
2nd right intercostal space on the right of upper sternum
