The part of the heart that separates the two ventricles from one another and thus stopping deoxygenated and oxygenated blood (bllod without/with oxygen respectively) from mixing.
Galen thought the septum had holes in, but he was wrong.
A hole in the septum is a serious problem.
The septum is very thick here.
Any female with very large mammary glands, tits, breasts, boobies, hooters or whatever you want to call them.
Man 1:Holy **** man look at the size of that girls tits!!!
Man 2: HEY BIG BIRD!