Lab 8

Question 1

What is the function of the auricle?

Answer 1

-increase volume of atria when venous return increases

Question 2

What artery and vein lie in the anterior IV sulcus?

Answer 2

LAD and great cardiac vein

Question 3

What artery and vein lie in the right coronary sulcus

Answer 3

Right coronary artery and small cardiac vein

Question 4

What layer of the pericardium is on the surface of the heart?

Answer 4

epicardium (visceral pericardium)

Question 5

What artery and vein lie in the posterior interventricular sulcus?

Answer 5

posterior interventricular artery and middle cardiac vein

Question 6

What artery and vein lie in the left coronary sulcus?

Answer 6

circumflex (left coronary), great cardiac vein (coronary sinus at back on right atrium)

Question 7

How do the surface features of the atria and auricle differ?

Answer 7

• inner surface of auricles is characterized by ridges while the walls of the atria are relatively smooth
• interior surfaces of the auricles are trabeculated due to irregular arrangement of bundles of myocardial fibres known as pectinate muscles

Question 8

What is the function of the papillary muscles?

Answer 8

-maintain tension on chordae tendinae during systole to prevent prolapse of AV valve

Question 9

When the fossa ovalis fails to form at birth and a hole remains present in the interatrial septum, what is this condition termed?

Answer 9

patent foramen ovale or ASD

Question 10

What lies inferior to the fossa ovalis?

Answer 10

-opening of the coronary sinus

Question 11

In an ischemic attack involving a partial blockage of the left coronary artery, papillary muscles of the left ventricle may become damaged. What effect would this have on blood flow through the left side of the heart?

Answer 11

• left AV valve may evert allowing blood to regurgitate back into the left atrium during systole
• net effect is less blood moves forward into aorta

Question 12

During what phase of the cardiac cycle does blood flow through the coronary arteries?

Answer 12

• during diastole
• at this time the myocardium is relaxed and the coronary vessels are open (not collapsed) allowing back pressure (diastolic pressure) in the aorta to drive blood flow through this circuit
• during systole, the aortic valve covers the openings of the coronary arteries in the aorta

Question 13

Describe ultrasound

Answer 13

• high frequency sound waves
• two dimensional image is generated by recording reflected sound waves which are displayed in real time
• air filled organs reflect ultrasound waves causing them to appear white
• fluid filled organs appear dark
• coupling gel has same conductivity as the body and therefore overcomes the sound barrier (air layer) between the skin and transducer

Question 14

What is the long axis vs short axis view?

Answer 14

• short axis: indicator dot on the tip of the ultrasound probe should point towards the right hip, opposite side will face towards armpit (RV, LV, IV septum)
• long axis: indicator dot should point towards right clavicle, opposite side will point in direction of apex of heart (left elbow) (RV, LV, LA, bicuspid, aortic valve)