Crossword Puzzle Four-lobed organ

Clue: Four-lobed organ

Lobed organ (e.g. EAR with 3 letters)
Fish tank organism (ALGA with 4 letters)
Organ pipe et al. (CACTI with 5 letters)
Small organs (SPINETS with 7 letters)
Many people in the same place, on Foursquare (SWARM with 5 letters)
Scents organ? (NOSE with 4 letters)
World Health Organization concern (FLU with 3 letters)
Fourth-brightest star of a constellation (DELTA with 5 letters)
Non-essential organ (SPLEEN with 6 letters)
Organization that began broadcasting on July 4, 1950 (RADIOFREEEUROPE with 15 letters)