Thorax III - Heart

Question 1

From what chamber of the heart can you see the Fossa Ovalis and what was it’s purpose?

Answer 1

• Can see FO from within the Right Atrium

- Reminant of Formen Ovali which allowed blood to bypass the pulmonary CCT as a fetus

Question 2

Describe the Left Atrium:

Answer 2

Forms base of heart: oriented posteriorly and inferiorly

- Receives both RIGHT AND LEFT paired pulmonary veins
- Walls are thicker than right side

Question 3

What important node is in the right atrium?

Answer 3

• S-A Node, within the crest terminalis

- Vascular supply: nodal artery

Question 4

Where is the atrioventricular node found?

Answer 4

• in the interatrial septum near coronary sinus

- Vascular supply: right coronary arteries

Question 5

What makes the left ventricle different from the right?

Answer 5

• More muscular wall

- LEFT GIVES RISE TO CORONARY ARTERIES THAT PERFUSE THE HEART

Question 6

When are Coronary Arteries perfused?

Answer 6

-PERFUSED DURING DIASTOLE unlike other arteries

Question 7

What plexus innervates the heart?

Answer 7

Cardiac plexus (autonomic)

Question 8

Which nervous system (parsymp/symp) dilates coronary vessels and which constricts?

Answer 8

• 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

Question 9

Describe the conduction of the heart:

Answer 9

• 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

Question 10

If blood flow to the AV bundle disrupted what structure is most likely impaired? What might AV bundle disruption cause?

Answer 10

• 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

Question 11

If a pacemaker is implanted where would it be placed?

Answer 11

• a pacemaker may be implanted into endocardium to fix this (above the area of damage)

Question 12

The left and right coronary sinus are ____ during systole and _____ during diastole

Answer 12

closed during systole and open (patent or perfused) during diastole

Question 13

From where does the right coronary artery arise?

Answer 13

The right coronary sinus and runs within the coronary (AV) sulcus

Question 14

The posterior inter ventricular branch anastomoses with

Answer 14

Anterior interventricular branch and the left circumflex branch of the left coronary artery

Question 15

What parts of the heart does the left coronary artery supply?

Answer 15

left atrium, left ventricle, inter ventricular septum, and the AV bundle

Question 16

the anterior inter ventricular A supplies what parts of the heart?

Answer 16

right and left ventricles and inter ventricular septum

Question 17

What is pulmonary valve incompetence?

Answer 17

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

Question 18

What is mitral stenosis?

Answer 18

• narrowing of the bicuspid valve causing it to not OPEN all the way
• Murmur upon auscultation of apex

Question 19

What is Aortic stenosis?

Answer 19

Obstruction of blood flow from left ventricle to aorta resulting in fusion of aortic valves, causes left ventricle hypertrophy

Question 20

What is CHD?

Answer 20

Coronary Heart disease, aka ischemic heart disease, via atherosclerosis of coronary arteries that supply the heart
**reduced blood flow to heart = decrease O2

Question 21

Coronary Artery Bypass Graft is for patients with:

Answer 21

Blocked left or right main coronary arteries, disease in several vessels, poor left ventricle function, debilitating chest pain

Question 22

What is a atherectomy?

Answer 22

high speed drill on catheter is used to shave plaque from artery

Question 23

What is a laser ablation?

Answer 23

Laser that burns away plaque to open the vessel

Question 24

List and describe the 3 layers of pericardium (external to internal)

Answer 24

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)

Question 25

Diastole is the first phase of the contraction cycle, and which heart sound?

Answer 25

2nd heart sound - ‘dub’

Question 26

What is happening in diastole in respects to the atria and ventricles? Where is the blood flowing?

Answer 26

• 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

Question 27

Systole is the second phase of the contraction cycle, and which heart sound?

Answer 27

1st heart sound - ‘lub’

Question 28

What is happening in systole in respects to the atria and ventricles? Where is the blood flowing?

Answer 28

• 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