Chapter 12: The heart Flashcards
What are the three layers of the cardiac valves?
1) a dense collagenous core (fibrosa) connected to supporting structures at the outflow surface
2) a central core of loose connective tissue (spongiosa)
3) a layer rich in elastin (atrilaris or ventricularis depending on the chamber) on the inflow side.
name the components of the cardiac conduction system:
1) the sinoatrial node (SA)
2) the atrioventricular node (AV)
3) the bundle of His
4) division of bundle of his into left and right - becomes the purkinje fibers.
Epicardial vs intramural
Whether the coronary arteries are inside or on the outside of the myocradium.
Name the three major cornoary arteries:
1) left anterior descending (LAD)
2) Left circumflex (LCX)
3) right coronary arteries
1 +2 arise from ythe left coronary artery
Cardiovascular dysfunction can be attributed to one of the following six pathogenic mechanisms.
1) heart pump failure (reduced cardiac output)
2) Flow obstruction
3) regurgitant flow (some blood flows back creating overload)
4) Shunted flow (flow through not normal paths eg infarcts)
5) Disorders of cardiac conduction
6) rupture of heart or majar vessel
CHF
Congestive heart failure - when the heart is unable to pump blood in a way which meets metabolic demands
Cause of heart hypertrophy :
Systemic increase in workload (eg from hypertension, infarction, stimulation etc)
What is Angina pectoris?
Recurrent attacks of chest pain/discomfort as a product of ischemia which is insufficient to cause myocardial necrosis.
What is MI?
Myocardial infarction - also more commonly known as a heart attack
What causes MI?
1) coronary artery occlusion
- caused by either atherosclerosis or thrombic events as product of hemorage, fissuring etc. By far th emost common. Also:
2) vasospasms
3) Emboli
4) Other reasons
What does the severity of the MI depend on?
1) rate, severity and location of the developed occlusion
2) The size of vascular bed perfused by the obstructed vessel
3) duration of occlusion
4) metabolic needs of the tissue
5) extent of colateral blood vessels
6)
What cellular structure first caves in?
The sarcolemma allowing intracardial proteins to go int the blood stream and is thereby a marker.
What is a transmural infarction?
Involves the full thickness of the heart wall - non-transmural does not. Typically epicardial occlusion.
Subendocardial infarction?
The inner most layer of the cardiac wall
Multifocal Microinfarction
Intramural vessels - so the area sorrounding a single capillary in the middle of the wall.
