Heart and circulation objectives

What are the layers of the heart

Epicardium/ Visceral pericardium

Myocardium

Endocardium - inside heart

Describe cardiac fat

Normal accumulations around epicardium and around base of the grooves

Differences in heart orientation between dog and cat

Cat hear sits more parallel with the sternum than in the dog

Cat sits more caudal between intercostal spaces 4-7 instead of 3-6

Where does the blood come from into right atrium

Cranial vena cava, caudal vena cava, coronary sinus

know schematic of pulmonary and systemic circulation

Diagram

What are the functions of the cardiac skeleton

Structural framework, attachment site for valve cusps, insulates the ventricles

Describe the heart sounds and what causes them.

S1 = closure of AV valves

S2 =closure of the semilunar valves

Systole = between S1 and S2

Diastole = between S2 and S1

what are the first branches off the aorta

Right and left coronary arteries which supply the myocardium

Describe cardiac conduction pathway

SA → AV node → AV bundle → right and left bundle branches → moderator bands → purkinje fibers

Arterial flow and supply diagram

Diagram

innervation of the head diagram

Diagram

Venous return flow and supply diagram

Diagram

Describe fetal circulation

Lungs and liver are bypassed because oxygenation and waste removal is primarily the responsibility of maternal supply and the placenta

There are some special Strucutres described above

What is the most common vascular ring anomaly in dogs and cats

Persistent right aortic arch with a left ligamentum arteriosum which encircles the esophagus