Fig. XCIV.1. The fibrous capsule of the hip-joint, laid open andturned aside to show, 2. the round ligament in its naturalposition.
1. The fibrous capsule of the hip-joint, laid open andturned aside to show, 2. the round ligament in its naturalposition.
Fig. XCV.A view of the head of the femur drawn out of its socket,and suspended by the round ligament, to show more clearlythe action of the ligament in retaining the head of thefemur in its socket.
A view of the head of the femur drawn out of its socket,and suspended by the round ligament, to show more clearlythe action of the ligament in retaining the head of thefemur in its socket.
200. Numerous and complicated ligaments connect the bones that form the knee-joint (fig. XCVI.), and the strength of these powerful bandsis greatly increased by the tendons that move the leg (fig. XCVI. 5), which pass over, and more or less surround, the joint.
Fig. XCVI.General view of the ligaments of the knee-joint. 1. Lowerend of the femur; 2. upper end of the tibia; 3. upper endof the fibula; 4. the patella; 5. united tendons of theextensor muscles; 6. ligaments of the patella; 7. the capsularinvestment of the knee; 8. the internal lateral ligament;9. the external lateral ligaments; 10. the posteriorligament; 11. the ligament connecting the tibia and fibula;12. a portion of the interosseous ligament.
General view of the ligaments of the knee-joint. 1. Lowerend of the femur; 2. upper end of the tibia; 3. upper endof the fibula; 4. the patella; 5. united tendons of theextensor muscles; 6. ligaments of the patella; 7. the capsularinvestment of the knee; 8. the internal lateral ligament;9. the external lateral ligaments; 10. the posteriorligament; 11. the ligament connecting the tibia and fibula;12. a portion of the interosseous ligament.
201. Strong ligaments maintain in their proper position the bones that form the ankle-joint (fig.XCVII.), connect the bones of the tarsus and metatarsus with one another (fig. XCVIII. 1), and articulate the several phalanges of the toes (fig. XCVIII. 2).
Fig. XCVII.General view of the posterior ligaments of the ankle-joint.1. Lower end of the tibia; 2. lower end of thefibula; 3. astragalus; 4. os calcis; 5. ligament betweenthe tibia and fibula; 6. ligament passing from the fibulato the astragalus; 7. ligament passing from the fibula tothe os calcis; 8. ligament passing from the tibia to theastragalus.
General view of the posterior ligaments of the ankle-joint.1. Lower end of the tibia; 2. lower end of thefibula; 3. astragalus; 4. os calcis; 5. ligament betweenthe tibia and fibula; 6. ligament passing from the fibulato the astragalus; 7. ligament passing from the fibula tothe os calcis; 8. ligament passing from the tibia to theastragalus.
Fig. XCVIII.General view of the ligaments of the sole of the foot.1. Ligaments connecting the bones of the tarsus; 2. ligamentsconnecting the bones of the toes.
General view of the ligaments of the sole of the foot.1. Ligaments connecting the bones of the tarsus; 2. ligamentsconnecting the bones of the toes.
202. The joint of the hip, like that of the shoulder, is capable of flexion, extension, and rotation; but its rotatory motions are to a much less extent, on account of the greater depth of the acetabulum and the stronger and shorter fibrous capsule. When the femur is flexed, the thigh is bent upon the pelvis, and its inferior extremity iscarried forwards. When it is extended, the thigh is carried backwards. The two thighs may be separated from each other laterally (abduction), or brought near to each other (adduction), or the one may be made to cross the other, and they may be rotated outwards or inwards.
203. The apparatus of muscles that produces these varied motions is seated partly on the trunk and partly on the pelvis. Thus, the powerful muscle that flexes the thigh, or that carries it forwards, termed the psoas (fig. XCIX. 1), arises from the last vertebra of the back, and successively from each vertebra of the loins (fig. XCIX. 1), and is inserted into the lesser trochanter of the femur (fig. XCIX. 3). Its action is assisted first by a large and strong muscle named the iliacus (fig. XCIX. 2), which occupies the whole concavity of the ilium (fig. XCIX. 2), and which, like the psoas, is inserted into the lesser trochanter of the femur (fig. XCIX. 3).
Fig. XCIX.View of the muscles that bend the thigh. 1. Themuscle called psoas; 2. the muscle called iliacus; 3. tendonsof these muscles, going to be inserted into the trochanterminor of the femur.
View of the muscles that bend the thigh. 1. Themuscle called psoas; 2. the muscle called iliacus; 3. tendonsof these muscles, going to be inserted into the trochanterminor of the femur.
204. The muscles that extend the thigh, or that carry it backwards, named the glutæi, the most powerful muscles of the body, are placed in successive layers, one upon the other, on the back part of the ilium (fig. C. 1, 2, 3), and are inserted into the linea aspera of the femur. They constitute the mass of flesh which forms the hip, and their powerful action in drawing the thigh backwards is assisted by several other muscles (fig. C. 4, 5, 6). Their action is never perfectly simple and direct; for those which move the thigh forwards sometimes carry it inwards, and sometimes outwards; and in like manner, those which move it backwards, at one time carry it inwards and atanother outwards, according to the direction of the fibres of the muscle and the position of the limb when those fibres act; while some of them, and more especially those which carry it backwards, at the same time rotate it, or roll it upon its axis.
Fig. C.View of the muscles that extend the thigh. 1. Themuscle called glutæus maximus, removed from its origin,2, 2, to show the muscles which lie beneath it; 2. cut edgeshowing the origin of the same muscle; 3. the musclecalled glutæus medius; 4, 5, 6. smaller muscles, assistingthe action of the glutæi.
View of the muscles that extend the thigh. 1. Themuscle called glutæus maximus, removed from its origin,2, 2, to show the muscles which lie beneath it; 2. cut edgeshowing the origin of the same muscle; 3. the musclecalled glutæus medius; 4, 5, 6. smaller muscles, assistingthe action of the glutæi.
205. The knee is a hinge-joint, admitting only of flexion and extension, and is therefore provided only with two sets of muscles, one for bending and the other for extending the leg. The flexors ofthe leg arise from the under and back part of the pelvis, are seated on the back part of the thigh,and are inserted into the upper part either of the tibia or of the fibula (fig. CI). They consist for the most part of three muscles, named the semi-tendinosus, the semi-membranosus (fig. CI. 3), and the biceps of the leg (fig. CI. 1). The tendons of the two former muscles, in passing to be inserted into the leg, form the inner, and that of the latter the outer, hamstrings (fig. CI. 4, 5).
Fig. CI.View of the flexor and extensor muscles of the leg.1. The biceps of the leg; 2. tendon of the biceps, insertedinto the head of the fibula; 3. the semi-membranosus,passing to be inserted into the head of the fibula; 4. tendonof the semi-membranosus forming the inner, and5. tendon of the biceps forming the outer, hamstring;6. upper part of the gastrocnemius muscle; 7. the four largemuscles which unite to form the great extensor muscle ofthe leg, inserted into 8. the patella; 9. a portion of theglutæus maximus concealing the other muscles of the hip.
View of the flexor and extensor muscles of the leg.1. The biceps of the leg; 2. tendon of the biceps, insertedinto the head of the fibula; 3. the semi-membranosus,passing to be inserted into the head of the fibula; 4. tendonof the semi-membranosus forming the inner, and5. tendon of the biceps forming the outer, hamstring;6. upper part of the gastrocnemius muscle; 7. the four largemuscles which unite to form the great extensor muscle ofthe leg, inserted into 8. the patella; 9. a portion of theglutæus maximus concealing the other muscles of the hip.
206. Four large muscles, blended together in such a manner as to form one muscle of prodigious size, termed the quadriceps cruris (fig. CI. 7), occupying nearly all the forepart and the sides, and a considerable portion of the back part of the thigh, constitute the great flexor of the thigh. This enormous mass of muscle arises partly from the ischium, and partly from the upper part of the femur (fig. CI. 7), and is all inserted into the patella (fig. CI. 8), which constitutes a pulley for the purpose of assisting the action of these powerful muscles.
207. The muscles which bend the toes and extend the foot, termed the gastrocnemii (fig. CII. 1, 2), are placed on the back part of the leg, and form the mass of muscle which constitutes the calfof the leg (fig. CII. 1, 2). They arise partly from the lower extremity of the femur (fig. CII.) and partly from the upper and back part of the fibula and tibia; and they form the largest and strongest tendon in the body, termed the tendo achillis (fig. CII. 3), which is implanted into the heel (fig. CII. 4).
Fig. CII.View of the muscles which bend the toes, and which, bylifting the heel, extend the foot. 1. The muscle calledgastrocnemius externus, which, uniting with 2. the gastrocnemiusinternus, forms 3. the tendo achillis, which is insertedinto 4. the heel.
View of the muscles which bend the toes, and which, bylifting the heel, extend the foot. 1. The muscle calledgastrocnemius externus, which, uniting with 2. the gastrocnemiusinternus, forms 3. the tendo achillis, which is insertedinto 4. the heel.
Fig. CIII.View of the muscles which extend the toes and bend thefoot. 1. The common extensor; 2. the tendons of the samemuscle inserted into the toes; 3. the anterior annularligament of the foot.
View of the muscles which extend the toes and bend thefoot. 1. The common extensor; 2. the tendons of the samemuscle inserted into the toes; 3. the anterior annularligament of the foot.
Fig. CIV.View of the muscles in the sole of the foot. 1 Themuscle which draws the great toe from the other toes; 2. themuscle which draws the little toe from the other toes;3. the muscle called the short flexor of the toes, whichassists in bending the four smaller toes.
View of the muscles in the sole of the foot. 1 Themuscle which draws the great toe from the other toes; 2. themuscle which draws the little toe from the other toes;3. the muscle called the short flexor of the toes, whichassists in bending the four smaller toes.
208. The muscles which extend the toes and bend the foot are seated on the fore part of the leg(fig. CIII.); split into tendons like the analogous muscles of the fingers (fig. CIII. 2); and are bound down by a ligament (fig. CIII. 3), exactly the same in name, disposition, and office, as that which belongs to the hand (fig. CIII. 3). Numerous minute muscles are placed in the sole of the foot (fig. CIV.), which act on the toes as the small muscles in the palm of the hand act on the fingers (fig. LXXXVI.).
209. Such are the moving powers which put in action the complicated mechanism provided for the function of locomotion. And these powers are adequate to their office; but they are what may be termed expensive powers; agents requiring a high degree, of organization and the utmost resources of the economy to support and maintain them. Hence in the construction of the framework of the machine which they have to move, whatever mechanical contrivance may economize their labour, is adopted. The construction, form, and disposition of the several parts of that framework have all reference to two objects: first, the combination of strength with lightness; and secondly, security to tender organs, with the power of executing rapid, energetic, and, sometimes, violent motions. The combination is effected and the object attained in a mode complicated in the detail, simple in the design, and perfect in the result. The weight of the body transmitted from the arch of the pelvis to a second arch, formed bythe neck of the thigh-bone, and from this, in a perpendicular direction, to a third arch formed by the foot, is ultimately received by the heel behind, and by the metatarsal bones and the first phalanges of the toes before, and more especially by the metatarsal joints belonging to the great and little toe, which have a special apparatus of muscles, for the purpose of preserving steadily their relative situation to the heel. The weight of the body is thus sustained on a series of arches, from which it is, in succession, transmitted to the ground, where it ultimately rests upon a tripod: forms known and selected as the best adapted to afford support, and to give security of position. Columns of compact bone superimposed one upon another, and united at different points by bands of prodigious strength, form the pillars of support. But these bony columns never touch each other; are never in actual contact; are all separated by layers of elastic matter which, while they assist in binding the columns together, enable them to move one upon another, as upon so many pliant springs. The layers of cartilage interposed between the several vertebræ; the layer of cartilage interposed between the vertebral column and the pelvis; the layer of cartilage that lines the acetabulum and that covers the head of the femur; the layer of cartilage that covers the lower extremity of the femur and the upper extremity of the tibia and fibula and the tarsus; the successivelayers of cartilage interposed between the several bones of the tarsus; and finally, the layer of cartilage that covers both the tarsal and the digital extremities of the metatarsal bones; are so many special provisions to prevent the weight of the body from being transmitted to the ground with a shock; and, at the same time, so many barriers established between the ground and the spinal cord, the brain and the soft and tender organs contained in the thoracic and abdominal cavities, to prevent these organs from being injured by the reaction of the ground upon the body. The excellence of this mechanism is seen in its results; in contemplating "from what heights we can leap—to what heights we can spring—to what distances we can bound—how swiftly we can run—how firmly we can stand—how nimbly we can dance—and yet how perfectly we can balance ourselves upon the smallest surfaces of support!"
210. It is necessary, in order to complete this general view of the structure of the human body, and of the combination and arrangement of its various parts, to denote the several regions into which, for the purpose of describing with accuracy the situation and relation of its more important organs, the body is divided. It is not needful to the present purpose to describe the regions of the head, because its internal cavity contains only one organ, the brain, and its external divisions do not differ materially from those which are commonand familiar; but the chest, the abdomen, and the upper and lower extremities are mapped out into regions, of which it is very important to have an exact knowledge, which may be acquired by the study of the annexed diagrams.
Fig. CV.Anterior view of the regions of the body. 1. Region of the neck;2. region of the chest or thorax. Abdominal regions: 3. epigastric;4. umbilical; 5. hypogastric region. Regions of the upper extremities.6. shoulder; 7. arm; 8. elbow; 9. fore-arm; 10. wrist; 11. ball ofthumb; 12. the axilla or armpit. Regions of the lower extremities:13. thigh; 14. knee; 15. leg; 16. ankle; 17. instep and foot.
Anterior view of the regions of the body. 1. Region of the neck;2. region of the chest or thorax. Abdominal regions: 3. epigastric;4. umbilical; 5. hypogastric region. Regions of the upper extremities.6. shoulder; 7. arm; 8. elbow; 9. fore-arm; 10. wrist; 11. ball ofthumb; 12. the axilla or armpit. Regions of the lower extremities:13. thigh; 14. knee; 15. leg; 16. ankle; 17. instep and foot.
Fig. CVI.Posterior view of the regions of the body: 18. region tothe scapula; 19. of the back; 20. of the loins; 21. of thehips; 22. of the ham; 23. of the calf of the leg; 24. of theheel and foot.
Posterior view of the regions of the body: 18. region tothe scapula; 19. of the back; 20. of the loins; 21. of thehips; 22. of the ham; 23. of the calf of the leg; 24. of theheel and foot.
Fig. CVII.Lateral view of the regions of the body: 25. arch ofthe foot.
Lateral view of the regions of the body: 25. arch ofthe foot.
Fig. CVIII.Anterior view of the situation of the more important internalorgans: 1. lungs, right and left; 2. heart; 3. linerepresenting the edge of the diaphragm; 4. liver; 5. stomach;6. small intestines; 7. colon; 8. urinary bladder.
Anterior view of the situation of the more important internalorgans: 1. lungs, right and left; 2. heart; 3. linerepresenting the edge of the diaphragm; 4. liver; 5. stomach;6. small intestines; 7. colon; 8. urinary bladder.
Fig. CIX.Posterior view of the situation of the more importantinternal organs: 9. kidnies, right and left; 10. the courseof the spinal cord.
Posterior view of the situation of the more importantinternal organs: 9. kidnies, right and left; 10. the courseof the spinal cord.
Fig. CX.Lateral view of the situation of the more importantinternal organs.
Lateral view of the situation of the more importantinternal organs.