"Feishu"(BL 13)is a commonly used acupoint in experimental study

but its definite position has not been described in current books about acupoints.In the present paper

the authors introduced three methods for determining the anatomical location of"Feishu"(BL 13)acupoint in rats.The Wistar rats(200±20)g were anesthetized with 10% chloral hydrate first

and then

fixed at the prone position.The highest point of the spinous process of the second thoracic vertebra was used as the marker for positioning the spinal vertebra.The point

7mm lateral to the site below the spinous process of the 3rd thoracic vertebra is just the"Feishu"(BL 13).In order to determine the 3rd thoracic vertebra

three methods are recommended to be adopted:1)finding the 5th thoracic vertebra process parallel to the inferior angle of the scapula first

then going upwards to find the 3rd thoracic vertebra

2)finding the 1st thoracic vertebra along the 1st rib

then going downward to find the 3rd thoracic vertebra

and 3)taking the 6th lumbar vertebra(parallel to the hip-joint)as the bone-marker and going upward to find the 3rd thoracic vertebra.When"Feishu"(BL 13)punctured

a filiform needle was straight inserted into the skin

then downward to the subcutaneous tissue

muscular layer(including the trunk cutaneous muscle

trapezius muscle

broadest muscle of back

serratus muscle of back

atalanto-longest muscle

longest muscle of neck

longest muscle of thorax

lumbar longest muscle

the medial part of the longest muscle

cervico-spinal muscle of back

semispinal muscle of neck

biventer cervicis

and multifidus muscles)about 6 mm in depth.