A spray nozzle for applying a medicinal agent to a tissue. The spray nozzle comprising a tip housing and a valve. The tip housing has a distal end, a proximal end, and a lumen that extends between the ends and defines a lengthwise central axis. The valve has an elongated body that extends through the lumen of the tip housing, along the lengthwise central axis. The valve, being configured to slide within the lumen of the tip housing, in an extended position with respect therewith is configured to disperse the medicinal agent toward the tissue. When the valve is in the retracted position with respect to the tip housing, the medicinal agent is vented away from the tissue.