Thorax III - Heart Flashcards
From what chamber of the heart can you see the Fossa Ovalis and what was it’s purpose?
- Can see FO from within the Right Atrium
- Reminant of Formen Ovali which allowed blood to bypass the pulmonary CCT as a fetus
Describe the Left Atrium:
Forms base of heart: oriented posteriorly and inferiorly
- Receives both RIGHT AND LEFT paired pulmonary veins - Walls are thicker than right side
What important node is in the right atrium?
- S-A Node, within the crest terminalis
- Vascular supply: nodal artery
Where is the atrioventricular node found?
- in the interatrial septum near coronary sinus
- Vascular supply: right coronary arteries
What makes the left ventricle different from the right?
- More muscular wall
- LEFT GIVES RISE TO CORONARY ARTERIES THAT PERFUSE THE HEART
When are Coronary Arteries perfused?
-PERFUSED DURING DIASTOLE unlike other arteries
What plexus innervates the heart?
Cardiac plexus (autonomic)
Which nervous system (parsymp/symp) dilates coronary vessels and which constricts?
- S: Dilates - more blood needed to provide oxygen to rapid beating heart
- PS: constricts - Relaxed mode, low heart rate so less O2 required to heart
Describe the conduction of the heart:
- Conduction in the heart begins at the S-A node (natural pace maker) and then to the A-V node
- Distally the AV bundle divides into R/L bundle branches w/in the interventricular septum
- This supplies the purkinje fibres and papillary muscles
If blood flow to the AV bundle disrupted what structure is most likely impaired? What might AV bundle disruption cause?
- Blockage of Anterior interventricular coronary arteries disrupts blood flow to AV bundle
- Leading to infarction in these regions
- Asynchronous contraction: Atria and ventricles then contract at different rates
If a pacemaker is implanted where would it be placed?
- a pacemaker may be implanted into endocardium to fix this (above the area of damage)
The left and right coronary sinus are ____ during systole and _____ during diastole
closed during systole and open (patent or perfused) during diastole
From where does the right coronary artery arise?
The right coronary sinus and runs within the coronary (AV) sulcus
The posterior inter ventricular branch anastomoses with
Anterior interventricular branch and the left circumflex branch of the left coronary artery
What parts of the heart does the left coronary artery supply?
left atrium, left ventricle, inter ventricular septum, and the AV bundle
the anterior inter ventricular A supplies what parts of the heart?
right and left ventricles and inter ventricular septum
What is pulmonary valve incompetence?
excess thickening of the pulmonary valves making them inflexible so they do not close completely resulting in back flow to the ventricle
-murmur on ausulation of pulmonary semilunar valve
What is mitral stenosis?
- narrowing of the bicuspid valve causing it to not OPEN all the way
- Murmur upon auscultation of apex
What is Aortic stenosis?
Obstruction of blood flow from left ventricle to aorta resulting in fusion of aortic valves, causes left ventricle hypertrophy
What is CHD?
Coronary Heart disease, aka ischemic heart disease, via atherosclerosis of coronary arteries that supply the heart
**reduced blood flow to heart = decrease O2
Coronary Artery Bypass Graft is for patients with:
Blocked left or right main coronary arteries, disease in several vessels, poor left ventricle function, debilitating chest pain
What is a atherectomy?
high speed drill on catheter is used to shave plaque from artery
What is a laser ablation?
Laser that burns away plaque to open the vessel
List and describe the 3 layers of pericardium (external to internal)
fibrous pericardium-external fibrous layer which is bound to surrounding structures (central tendon, sternum and connective tissue)
serous pericardium:
-parietal layer (lines internal surface of fibrous pericardium)
-visceral layer (also called epicardium, external surface of myocardium)
Diastole is the first phase of the contraction cycle, and which heart sound?
2nd heart sound - ‘dub’
What is happening in diastole in respects to the atria and ventricles? Where is the blood flowing?
- ventricular relaxation; closure of aortic and pulmonary semi-lunar valves
- atrial contraction; opening of A-V valves
- end of diastole is when ventricles contract
- blood is flowing from atria into the venticles
Systole is the second phase of the contraction cycle, and which heart sound?
1st heart sound - ‘lub’
What is happening in systole in respects to the atria and ventricles? Where is the blood flowing?
- closure of A-V valves
- ventricular contraction ejects blood out through the semi-lunar valves into the great vessels of the heart
- ends with ventricular relaxation
