ARTICULA TIONS.HGAMEN TS. 423 



for locating lacerations in rare instances) as well as an arbitrary practice. There 

 is no well-defined line of demarcation between a lateral and an anterior part of 

 a capsule, as the student may expect to find, since transitions in anatomy are 

 easy and gradual. 



8. Strengthening or accessory bands are derived either from the deep fascia 

 or from the aponeurosis <>t a muscle crossing a joint. 



9. By incorporation of tendons in a capsule, the capsule becomes stronger 

 where the incorporation occurs. Growth is the correlative of function, you will 

 remember ; now, if from change in environment an animal acquire altered body 

 movements, a muscle may migrate from its primitive insertion below a joint to 

 an acquired insertion above a joint. Loss of function entails loss of specific char- 

 acter ; in this case loss of specific character that is, loss of muscular element 

 leaves only the connective-tissue framework crossing the joint. The muscle 

 migrated, the tendon became divorced, and by vigorous retrogression of muscle, 

 a band of connective tissue remains which strengthens the capsule ; the original 

 tendon became incorporated with the capsule. The divorced tendon of the 

 adductor magnus obtains as the internal lateral ligament of the knee-joint ; that 

 of the peroneus longus' as the external lateral ligament. The coraco-humeral 

 ligament is the divorced tendon of the minor pectoral muscle. The greater 

 sacro-sciatic ligament is the divorced tendon of the biceps femoris. The liga- 

 mentum teres in the hip-joint is said by Morris to be in all probability the 

 divorced tendon of the pectineus muscle. 



10. The movements of joints are often limited by bone. Note should be 

 taken of these physiological limitations on the cadaver when you dissect liga- 

 ments. 



11. Ligamentous muscles to a joint are such muscles as cross a joint. The 

 biceps, brachialis anticus, triceps, and all the muscles getting origin from the 

 humeral condyles are ligamentous in their action to the elbow-joint. Muscles 

 as the rectus femoris and the sartorius may be ligamentous to more than one 

 joint. Ligamentous muscles are also called the elastic ligaments of a joint. 



12. Note the entrance of nerves and vessels that supply the synovial mem- 

 brane. . Such structures are designated articular. In this connection refer to 

 Hilton's law governing articular nerves. This law is given in the introductory 

 chapter of this book on page 19. 



13. Finally, having found in the make-up of movable joints bone, articular 

 lamella, cartilage, ligament, tendon, muscle, synovial membrane, nerve, and 

 blood-vessels, be able to classify these structures histologically, according to the 

 outline given in the beginning of this work under caption of anatomical tissues. 

 The plan just outlined for your guidance will not only give you a thorough un- 

 derstanding of the ligaments, but will refresh your memory on those very prac- 

 tical points you will so much need in your subsequent medical studies, both as 

 students and as practitioners of medicine. 



Whenever you are in doubt as to the name of a particular subdivision of a 

 class, consult the following table, taken from Morris : 



TABLE OF THE VARIOUS CLASSES OF JOINTS. 



Class. Examples. 



I. Synarthrosis 



(a) True sutures Lambdoid, sagittal, coronal. 



(A) False sutures Internasal. Intermaxillary. Costo-chondral. 



(f) Grooved sutures Vomer and rostrum of sphenoid. 



II. Amphiarthrosis Bodies of vertebrae. Symphysis pubis, sacro- 



iliac, sacro-coccygeal. 



