148 Commentary on plates 67 & 68.
When any of the arteries of the leg or the foot are wounded, and the haemorrhage cannot be commanded by compression, it will be necessary to search for the divided ends of the vessel in the wound, and to apply a ligature to both. The expediency of this measure must become fully apparent when we consider the frequent anastomoses existing between the collateral branches of the crural arteries, and that a ligature applied to any one of these above the seat of injury will not arrest the recurrent circulation through the vessels of the foot.
DESCRIPTION OF PLATES 67 & 68.
PLATE 67.
FIGURE 1.
A. The tendon of the tibialis anticus muscle.
B B. The long saphena vein.
C C. The tendon of the tibialis posticus muscle.
D. The tibia; d, the inner malleolus.
E E. The tendon of the flexor longus digitorum muscle.
F. The gastrocnemius muscle; f, the tendo Achillis.
G. The soleus muscle.
H. The tendon of the plantaris muscle.
I I. The venae comites.
K K. The posterior tibial artery.
L L. The posterior tibial nerve.
FIGURE 2.
A. The tibialis anticus muscle; a, its tendon.
B. The extensor longus digitorum muscle; b b b b, its four tendons.
C C. The extensor longus pollicis muscle.
D D. The tibia.
E. The fibula; e, the outer malleolus.
F F. The tendon of the peronaeus longus muscle.
G G. The peronaeus brevis muscle; i, the peronaeus tertius.
H H. The fascia.
K. The extensor brevis digitorum muscle; k k, its tendons.
L L. The anterior tibial artery and nerve descending to the dorsum of the foot.
Plate 67, Figures 1, 2.
PLATE 68.
FIGURE 1.
A. The calcaneum.
B. The plantar fascia and flexor brevis digitorum muscle cut; b b b, its tendons.
C. The abductor minimi digiti muscle.
D. The abductor pollicis muscle.
E. The flexor accessorius muscle.
F. The tendon of the flexor longus digitorum muscle, subdividing into f f f f, tendons for the four outer toes.
G. The tendon of the flexor pollicis longus muscle.
H. The flexor pollicis brevis muscle.
i i i i. The four lumbricales muscles.
K. The external plantar nerve.
L. The external plantar artery.
M. The internal plantar nerve and artery.
Plate 68, Figure 1
FIGURE 2.
A. The heel covered by the integument.
B. The plantar fascia and flexor brevis digitorum muscle cut; b b b, the tendons of the muscle.
C. The abductor minimi digiti.
D. The abductor pollicis.
E. The flexor accessorius cut.
F. The tendon of the flexor digitorum longus cut; f f f, its digital ends.
G. The tendon of the flexor pollicis.
H. The head of the first metatarsal bone.
I. The tendon of the tibialis posticus.
K. The external plantar nerve.
L L. The arch of the external plantar artery.
M M M M. The four interosseous muscles.
N. The external plantar nerve and artery cut.
Plate 68, Figure 2
CONCLUDING COMMENTARY.
ON THE FORM AND DISTRIBUTION OF THE VASCULAR SYSTEM AS A WHOLE.
ANOMALIES.--RAMIFICATION.--ANASTOMOSIS.
I.--The heart, in all stages of its development, is to the vascular system what the point of a circle is to the circumference--namely, at once the beginning and the end. The heart, occupying, it may be said, the centre of the thorax, circulates the blood in the same way, by similar channels, to an equal extent, in equal pace, and at the same period of time, through both sides of the body. In its adult normal condition, the heart presents itself as a double or symmetrical organ. The two hearts, though united and appearing single, are nevertheless, as to their respective cavities, absolutely distinct. Each heart consists again of two compartments--an auricle and a ventricle. The two auricles are similar in structure and form. The two ventricles are similar in the same respects. A septum divides the two auricles, and another--the two ventricles. Between the right auricle and ventricle, forming the right heart, there exists a valvular apparatus (tricuspid), by which these two compartments communicate; and a similar valve (bicuspid) admits of communication between the left auricle and ventricle. The two hearts being distinct, and the main vessels arising from each respectively being distinct likewise, it follows that the capillary peripheries of these vessels form the only channels through which the blood issuing from one heart can enter the other.
II.--As the aorta of the left heart ramifies throughout all parts of the body, and as the countless ramifications of this vessel terminate in an equal number of ramifications of the principal veins of the right heart, it will appear that between the systemic vessels of the two hearts respectively, the capillary anastomotic circulation reigns universal.
III.--The body generally is marked by the median line, from the vertex to the perinaeum, into corresponding halves. All parts excepting the main bloodvessels in the neighbourhood of the heart are naturally divisible by this line into equals. The vessels of each heart, in being distributed to both sides of the body alike, cross each other at the median line, and hence they are inseparable according to this line, unless by section. If the vessels proper to each heart, right and left, ramified alone within the limits of their respective sides of the body, then their capillary anastomosis could only take place along the median line, and here in such case they might be separated by median section into two distinct systems. But as each system is itself double in branching into both sides of the body, the two would be at the same time equally divided by vertical section. From this it will appear that the vessels belonging to each heart form a symmetrical system, corresponding to the sides of the body, and that the capillary anastomosis of these systemic veins and arteries is divisible into two great fields, one situated on either side of the median line, and touching at this line.
IV.--The vessels of the right heart do not communicate at their capillary peripheries, for its veins are systemic, and its arteries are pulmonary. The vessels of the left heart do not anastomose, for its veins are pulmonary, and its arteries are systemic. The arteries of the right and left hearts cannot anastomose, for the former are pulmonary, and the latter are systemic; and neither can the veins of the right and left hearts, for a similar reason. Hence, therefore, there can be, between the vessels of both hearts, but two provinces of anastomosis--viz., that of the lungs, and that of the system. In the lungs, the arteries of the right heart and the veins of the left anastomose. In the body generally (not excepting the lungs), the arteries of the left heart, and the veins of the right, anastomose; and thus in the pulmonary and the systemic circulation, each heart plays an equal part through the medium of its proper vessels. The pulmonary bear to the systemic vessels the same relation as a lesser circle contained within a greater; and the vessels of each heart form the half of each circle, the arteries of the one being opposite the veins of the other.