Working for Crossbones.
yes.
The Russian dudes.
It is Radames the captain of the guards in the Opera Aida
Razoul : The Captain of the Guard .
The Lower Esophageal Sphincter.
Not sure, The RSM Coldstream Guards is John Sheard but it might not have been him.
King Xerxes was assassinated in 465 BCE, stabbed by the captain of the guards.
Aortic Semilunar Valve
The opening lines start the play off like other plays, with an exposition. There are guards waiting for an impending attack while one of the guards fear that there is a ghost among them. The unease comes from the guard who is "sick at heart" (the ghost is making him nervous).
No, not serving. There are of course guards outside the embassy
That is the correct spelling of the Biblical name Potiphar. He is in the book of Genesis as the captain of guards who imprisons Joseph during his captivity.
The epiglottis is what guards the entrance of the opening in the vocal folds. During the action of swallowing, it allows food to pass and go down the esophagus.