ANTERIOR CRURAL NERVE. 
sheath and femoral vessels. 
of branches, among which the external circumflex 
artery passes. 
The branches of the anterior crural nerve, which 
are (1) muscular, (2) articular, and (3) cutaneous, 
arise in the following way :— 
In the abdomen a muscular branch arises from the 
outer side of the nerve and enters the iliacus muscle. 
In Scarpa’s triangle the terminal muscular, 
articular, and cutaneous branches of the nerve arise 
in the form of a large bundle of nerves. 
1. The muscular branches supply the pectineus, 
sartorius, and quadriceps extensor. The nerve to 
the pectineus arises close to Poupart’s lgament, 
and coursing obliquely downwards and inwards 
behind the femoral vessels enters the muscle at its 
outer border. It is not unfrequently double. It 
sometimes gives off a fine communicating branch to 
the superficial part of the obturator nerve. The 
nerves to the sartorius are in two sets: an outer 
short set of nerves associated with the outer part of 
the middle cutaneous nerve, which enter the upper 
part of the muscle; and an inner longer set which 
are associated with the imner part of the middle 
cutaneous nerve, and supply the middle of the 
muscle. The parts of the quadriceps extensor are 
suppled by several branches. The vastus externus 
and rectus femoris are supplied on their deep surface 
by separate nerves which are accompanied by branches 
of the external circumflex artery. The crureus 
muscle is supplied superficially by a nerve which 
passes through the muscle, and innervates also the 
subcrureus. It also receives fibres from one of the 
nerves to the vastus internus. The vastus internus 
muscle is supplied by two nerves: an upper trunk, 
which supplies the higher part of the muscle, and 
sends fibres to the crureus as well; and a lower 
trunk, which descends on the outer side of the 
femoral artery along with the internal saphenous 
nerve, and passing beneath the sartorius, over or 
under the aponeurotic covering of Hunter’s canal, 
enters the inner side of the vastus internus muscle. 
This nerve gives off a small branch which enters the 
medullary canal of the femur. 
2. The articular branches supply the hip and knee 
joints. The articular branch to the hip joint arises 
from the nerve to the rectus femoris, and is accom- 
panied by branches from the external circumflex 
artery. The articular branches to the knee joint are 
four in number. Three of them arise from the 
nerves to the vastus externus, crureus, and vastus 
internus, which, after the muscular nerves are given 
off, are continued downwards to the knee joint along 
the front of the femur. A fourth articular branch 
arises (sometimes) from the internal saphenous nerve. 
5. The cutaneous branches are the middle and 
internal cutaneous, and the internal saphenous nerves 
(Fig. 442). 
603 
In Scarpa’s triangle it breaks up into a large number 
i; f\ A T)\ 
Fic. 442.— DIsTRIBUTION OF CuUTA- 
NEOUS NERVES ON THE FRONT OF 
THE LOWER LIMB. 
On the one side the distribution of the 
several nerves is represented, the 
letters indicating their nomenclature. 
T.11, Branches of eleventh thoracic 
nerve ; 7T.12, Branches of twelfth 
thoracic nerve; I.H, [io-hypogastric ; 
II, Nlio-inguinal; E.C, External cuta- 
neous ; G.C, Genito-crural ; M.C!,2, 
Middle cutaneous; I.C!,2, Internal 
cutaneous ; Ost, Obturator; §8.Sce, 
Small sciatic ; Pat. PLEx, Patellar 
plexus; Pav, Patellar branch of 
internal saphenous; E.P.S, Sural 
branches of peroneal nerve; I.5, 
Internal saphenous ; M.C, Musculo- 
cutaneous ; E.S, External saphenous ; 
A.T, Anterior tibial. 
On the other side a schematic repre- 
sentation is given of the areas sup- 
plied by the above nerves, the letters 
indicating the spinal origin of the 
branches of distribution to each area. 
The middle cutaneous nerve arises in two parts, an external and an vnternal 
