Anatomy Flashcards
What are three key features that enable the heart to simultaneously maintain 2 separate circuits of blood through the body with equal volumes?
- Self-stimulating sinoatrial nodal cells
- Gap junctions: rapid spread of signal
- INSULATED conducting system from the atria to the ventricles
Insulation via the fibrous skeleton and fibrous septum
Where exactly is the heart located in the body?
At the anterior portion of the middle mediastinum
How much fluid is in the pericardium?
20-30 ml
What is cardiac tamponade and how do you treat it?
When blood escapes from the heart due to injury, fills up the pericardium, thereby restricting the heart.
Pericardiocentsis: insert a needle in the left infrasternal angle toward the left shoulder in order to avoid puncturing the left lung, and remove excess pericardial fluid.
When you do CPR, what exactly is happening, and how effective is it?
You are squeezing the ventricles inbetween the lower half of the sternum and the rigid spine.
100 compressions/minute = 30% of resting cardiac output.
What parts of the heart are on the left and right borders in an PA chest xray?
Right: right atrium
Left: left ventricle
What parts of the heart are in the anterior and posteror
of a lateral xray?
Anterior: right ventricle
Posterior: left atrium and ventricle
What chamber of the heart is at the base of the heart?
left atrium
What is the difference between a right dominant
and left dominant heart?
Right dominant (90%) the posterior descending artery PDA comes from the right coronary artery
Left dominant (10%) the posterior descending artery PDA comes from the circumflex branch of the left coronary artery
NOTE: the PDA runs along the atrioventricular groove
What are the five great vessels of the heart?
Superior and Inferior Vena Cava
Pulmonary Artery and Vein
Aorta
(Note: from the aorta come the brachiocephalic, common carotid and subclavian arteries)
What part of the cardiac cycle fills the coronary arteries?
Diastole
(During systole the huge flow of blood compresses the intramyocardial branches so that blood cannot get through to the coronary arteries.)
What parts of the heart
do the left and right coronary arteries supply?
It can vary a bit from person to person, but…
Right coronary artery supplies the right atrium and most of the right ventricle, with some of the left atrium and ventricle.
Left coronary artery supplies all else, and notably the interventricular septum.
What are the two branches of the left coronary artery?
Left Anterior Descending LAD
Circumflex Branch
Where exactly do the SVC and IVC enter the heart?
SVC: manubriosternal joint
IVC xiphosternal joint
Where do the coronary arteries originate?
In the right and left semilunar cusps of the aortic valve.
