The coolant enters the cylinder from the cases through  a hole on the right side of the exhaust port.  The head returns the coolant to the radiator.  The outlet in the head is almost directly above where the coolant enters the cylinder. 

The small holes in the front of the head gasket force the majority of the coolant to flow around the left and right side of the cylinder to the rear of the cylinder.  Once the coolant streams have traveled around both sides of the cylinder, it travels up through the large holes in the head gasket ino the rear of the head.  The coolant now flows over the combustion chamber to the water outlet in the head and then back to the top of the radiator.