A control arm has two bushes on the inner part, i.e a bottom arm and a radius rod built into the same unit. that is where the confusion normally comes from.

Excellent idea, Jack!

#1 is also known as the "knuckle arm" (with ball joint attached to it)

#5 is aka "lower arm". Dattodevil, I think you mean a "lower a-arm". The 1200 one here isn't an "a" (two inner bushings), but a simple lower arm link.

Here are the official Nissan part names for these 1200 components:
1. ARM-knuckle (w/BALL JOINT ASS'Y-lower)
2. ROD ASS'Y-side
3. ROD-tension, front suspension
4. BAR-torsion, front stabilizer
5. LINK ASS'Y - transverse

1 Steering arm and lower ball joint
2 inner anad outer tie rod assembly
3 tension rod (castor rod)
4 stabilizer bar (anti sway bar)
5 lower control arm (transverse link, A arm)

As you can see, there is alot of names and descriptions for the same piece of hardware, some correct some not so. To be accurate the manufacturer has the only true description.
The desciption can change with locality, so if you are trying to find the right terminology go genuine or use the local lingo, but really it doesn't matter too much what you call it as long as the person you are talking to understands what part you are descibing.

try this link for another view

Nolathane

Single Joint Spring Strut = Mac Pherson strut