Cardiac Anatomy Flashcards
What are the cardinal symptoms of Cardiac Dysfunction?
- Fatigue
- Activity limitation/exercise intolerance
- Congestion/fluid acculumation in lungs
- dyspnea/breathing difficulty
- Edema
- SOB/dyspnea/breathlessness
How many ribs and intercostals spaces are there?
- 12 ribs
- 11 intercostal spaces
- numbered according to the rib forming the superior border
what is the sternal angle?
“angle of Louis”
anterior angle formed by the junction of the manubrium and the body of the sternum
the sternal angle is a surface landmark for ______
the bifurcation of the trachea into the R and L main stem bronchi
the sternal angle is also a landmark for what vascular structures?
- Aortic arch
- starts and ends (dorsally) at the ange
- descending aorta begins at this level (dorsally)
What vascular and neural structures can be found just below the sternal angle?
- Pulmonary trunk divides into 2 pulmonary arteries
- Cardiac plexus is situated here (just below the aortic arch)
Which ribs are True/False ribs?
- True ribs = 1-7
- False ribs = 8, 9, 10
- False floating ribs = 11, 12
T/F: all thoracic organs are found within the mediastumn
FALSE
the lungs sit on either side
T/F: the contents of the mediastumn are mobile
TRUE
the heart contracts and relaxes-moves a great deal
how can standing/sitting position alter the contents of the mediastiumn?
- Supine
- contents move superiorly secondary to abdominal viscera pushing medistinal contents superiorly
- Standing
- gravity pulls the mediastinal contents downward
- contents can be shifted by air trapped in pleural space or following removal of a lung
describe the position of the heart
It lies obliquely in the middle of the mediastinum
- 2/3rds located to the L of the sternum
- points slightly anteriorly
- extends from 2nd to 5th intercostal space
what structures make up the R border of the heart?
- IVC
- right atrium
- SVC
what structures make up the L border of the heart?
- left ventricle
- left atrium
- pulmonary trunk
- arch of aorta
what structures make up the superior border of the heart?
- right and left atrium
- SVC
- ascending aorta
- pulmonary trunk
what structures make up the inferior border of the heart?
- right ventricle
describe the anterior axillary line
imaginary line that starts from the lateral end of the clavicle, lateral edge of the pectoralis major muscle
describe the midaxillary line
an imaginary line between the anterior axillary line and the posterior axillary line
describe the posterior axillary line
marked by the posterior axillary fold (latissimus dorsi and teres major muscle)
describe the midclavicular line
an imaginary line parallel to the long axis of the body and passing through the midpoint of the clavicle on the ventral surface of the body
describe the pericardium
encloses the heart and the roots of the great vessels
made up of the serous and fibrous pericardium
what is the fibrous pericardium?
- tough fibrous connective tissue
- prevents overfilling of the heart
- lies posterior to the sternum and 2nd-6th costal cartilage and anterior to T5-T8
- attaches inferiorly to the central tendon of the diaphragm and to the tunica externa of the great vessels superiorly
the epicardium is the same as _____
the visceral pericardium
where is the SA node located?
just lateral to the junction where the superior vena cava enters the right atrium
located in the myocardial layer
where is the pulmonary valve located?
- between RV and pulmonary trunk
- lies at the apex of the conus arteriosus a the level of the 3rd costal cartilage
what makes up the inflow and outflow tract of the R Ventricle?
- Inflow tract
- tricuspid valve
- chordae tendineae
- papillary muscles
- base of the R ventricle chamber
- Outflow tract
- R ventricular free wall
- ventricular septum
- conus arteriosus (infundibulum)
describe pressures within the R Ventricle
- Diastolic Pressure
- ranges from 0-8 mmHg
- Systolic Pressure
- ranges from 15-30 mmH
- Increased pulmonary pressures increase work load on the RV results in cor pulmonale
how can RA impact the heart?
- Clinically apparent rheumatoid heart disease occurs in 25-40% of pts
- Rheumatoid heart disease may appear as:
- pericarditis
- myocarditis
- valvular heart disease
- atherosclerotic CAD
- coronary arteritis
- aoritis
- cor pulmonale
- conduction disturbances
describe the inflow and outflow tracts of the L ventricle
- Inflow tract
- funnel shaped and surrounded by the mitral valve annulus, leaflets and chordae tendineae
- Outflow tract
- formed by smooth basal (muscular) portion of the interventricular septum, the anterior ventricular wall and the anterior mitral leaflet
- **note → the muscular septum bulges into the left ventricular outflow tract
conduction velocity within the heart is altered by ____
- sympathetic stimulation (increases)
- vagal stimulation (decreases)
- ischemia/hypoxia (decreases)
- drugs (adrenergic and cholinergic)
- increase or decrease
coronary arteries recieve blood only during _______
diastole
coronary arteries are blocked during systole resulting from external compression of coronary vessels by contracting myocardial tissue during systole (compression tissue pressure)
describe blood flow within the coronary arteries
- at rest, approximately 60-70% of oxygen is extracted from blood in the coronary arteries
- exercise has only limited effect on cardiac O2 extraction
- decreased amount of time spent in diastole - can decrease the efficiency of myocardial perfusion
- increased work of the heart can reduce perfusion
- think uncontrolled HTN
List the coronary arteries
- Right coronary arteries
- Posterior interventricular artery
- Right marginal artery
- Left coronary artery
- Circumflex artery
- Anterior interventricular artery
describe the location of the RCA
- arises above the right cusp of the aortic valve, passes between the auricular appendages of the right atrium and the pulmonary trunk and travels down the right AV groove to come around the right (acute) margin of the heart and into the posterior interventricular sulcus becoming the posterior descending artery
- continues inferiorly
what does the RCA perfuse?
- the wall of the RV (acute marginal A)
- interventricular septum
- 25-35% of the LV
- SA node
- Contributes to the perfusion of the AV node
the LCA splits into what 2 major branches?
- Anterior interventricular (aka left anterior descending artery LAD)
- the circumflex - 2nd major branch
describe the LAD
- follows the anterior interventricular groove
- supplies blood to the anterior and septal aspects of the left ventricle, apex, and interventicular septum
- approximately 70% of the left ventricle is perfused by the LAD artery
- “widow maker”
describe the circumflex artery
- runs in the coronary sulcus between the left atrium and ventricle and curves around the left margin of the heart and heads posteriorly
- it reaches nearly as far as the posterior longitudinal sulcus and helps form the posterior interventricular artery
- it perfuses the posterior and lateral aspects of the LV and the papillary muscles and the SA node
describe the venous supply of the heart
most of the veins of the heart drain into the coronary sinus which runs in the posterior aspect of the coronary sulcus and then drains through the valve of the coronary sinus, a semilunar flap, into the R atrium
