560 DISSECTION OF THE THIGH. 



the aponeurosis of the external oblique muscle of the abdomen, which 

 stretches from the front of the iliac crest to the pubes (p. 411). When 

 viewed on the surface, the arch is curved downwards towards the limb, 

 whilst the fascia lata remains on the thigh. The outer half is oblique. 

 But the inner half is almost horizontal, and widens as it approaches the 

 pubes, where it is inserted into the pubic spine and pectineal line of the 

 hip bone, forming Gimbernat's ligament. 



The space between the crural arch and the innominate bone is larger in 

 the female than in the male, and is closed by parts passing from the abdo- 

 men to the thigh. The outer half of the interval is filled by the fleshy 

 psoas and iliacus muscles, to which the arch is closely bound by fascia ; 

 and the inner half is occupied by the femoral vessels and their sheath. 



Gimbernat's ligament, or the part of the tendon of the external oblique 

 muscle which is inserted into the pectineal line, is about three-fourths of 

 an inch in length, and is triangular in shape. Its apex is at the pubic 

 spine ; whilst its base is in contact with the crural sheath, and is joined 

 by the fascia lata. By one margin (anterior) it is continuous with the 

 crural arch, and by the opposite it is fixed to the pectineal line. In the 

 erect position of the body the ligament is almost horizontal. 



The crural sheath (tig. 194, B ) is a loose tube of membrane around the 

 femoral vessels. It has the form of a funnel, sloped unequally on the sides. 

 The wide part or base of the tube is upwards; and the narrow part ceases 

 about two inches below Poupart's ligament, by blending with the common, 

 areolar sheath of the bloodvessels. Its outer border is nearly straight, and 

 is perforafeci by /the genito-crural nerve ( 1 ). Its inner border is oblique, 

 and is pierced by lymphatics, superficial vessels, and the saphenous vein(/) ; 

 this part of the sheath appears in the saphenous opening, and is connected 

 to the falciform margin and the superficial fascia. In front of the crural 

 sheath and behind it is the fascia lata of the thigh. 



The sheath is continuous with the fasciae lining the abdomen in this 

 way ; the anterior part is prolonged beneath Poupart's ligament into the 

 fascia trans versalis, and the posterior half is continued into the fascia 

 iliaca (p. 428). 



Crossing the front of the sheath beneath the arch of Poupart's ligament, 

 is a fibrous band, the deep crural arch. A notice of it is included in the 

 description of the fascia transversalis (p. 419). 



Dissection (fig. 194). The student is to open the sheath by an incision 

 across the front, and to raise the loose anterior part with hooks. Inside 

 the tube are contained the femoral vessels, each surrounded by its covering 

 of areolar tissue, together with an inguinal gland ; and if a piece of the 

 areolar casing be cut out over both the artery and the vein, there will be 

 an appearance of two thin partitions, the one being situate on the inner 

 side of the vein, separating this vessel from the gland, and the other (J) 

 between the vein and the artery. A fatty stratum stretches over the upper 

 aperture of the sheath, closing it towards the abdomen. 



Interior of the crural sheath (fig. 194). The sheath is said be be divided 

 into three compartments by two partitions ; and the position of the so- 

 called septa has been before referred to one being internal to the femoral 

 vein, and the other between the two large vessels. In the outer compart- 

 ment is contained the femoral artery (a), lying close to the side of the 

 sheath ; in the middle one is placed the femoral vein (b) ; and in the inner 

 space (crural canal) only a lymphatic gland (c) is situate. 



The crural canal (fig. 192) is the innermost space in the interior of the 



