Objective To observe the structure of acupoints: "Shangyang"(LI 1)

"Erjian"(LI 2)

"Sanjian"(LI 3)

"Hegu"(LI 4) and "Quchi"(LI 11) of the Yangming Meridian in the rabbit's forelimb.Methods The acupoints were first located in accordance with the related atlas of rabbits and confirmed by low resistance and higher electric potential determinations by using a "multipurpose electronic acupoint detection and therapeutic instrument".Then the animals under anesthesia were killed by intravenous injection of air embolism

perfused with 5% natrium citricum first

acetic ether containing acrylonitrile-butadiene-styrene copolymer

and 5% dicapryl phthalate

blue and red pigments for paintings via subclavian artery

respectively.After routinely inserting an acupuncture needle into the acupoint

the local tissues(muscles

blood vessels and nerves) of the acupoints mentioned above were dissected layer by layer and their relations with the needle were observed under microscope.Results "Erjian"(LI 2) is situated at the depression site distal to the second metacarpophalangeal joint on the radial side."Sanjian"(LI 3) is located at the depression site proximal to the second metacarpophalangeal joint on the radial side.The shallow-layers of "Shangyang"(LI 1)

"Erjian"(LI 2)

"Sanjian"(LI 3)

"Hegu"(LI 4) and "Quchi"(LI 11) mainly contain cephalic vein and shallow branches of the radial nerve

and their deep layers chiefly contain radial artery and its branches

and the median nerve.Conclusion "Shangyang"(LI 1)

"Erjian"(LI 2)

"Sanjian"(LI 3)

"Hegu"(LI 4) and "Quchi"(LI 11) have a close association with the cephalic vein

radial artery

radial vein and its branches

superficial branch of radial nerve and the median nerve

which constitutes the morphological basis of the five points.