Main vein, Central vein, Mid vein are all correct to a point. "Rachis" seems to be the scientifically preferred term, though.
"Midrib" also sees some usage in a few types of leaf.
RIB
It is called a vein.
The central vein can be called a midrib or mid-vein
the line that goes through the middle of a leaf is called a vein.
main vein / leaf blade
No
The middle of a leaf is taken up by a vein called the midrib. -Andrew D.
The scientific term for the vein of a leaf is Xylem and phloem.
The large veins on the penis are called the dorsal veins of the penis.
It depends on what sort of leaf. In broad leaved flowering plants it is normally down the middle. Gingko biloba doesn't have a main vein but many radiating from the stem. The Narrow leaved flowering plants have a series of so called main veins. The conifers don't have leaves, they have needles.
Because main vein has to be strong enough to support the leaf blade.
lateral vein is hindi ko alam
lateral vein is hindi ko alam