FUNDAMENTAL PRINCIPLES OF ANATOMY. 25 



on the anterior surface of the tibia and fibula in front. The superficial group 

 behind is separated from the deep group. 



3. The radial group of the forearm is separated from the flexors in front and 

 the extensors behind. The superficial is separated from the deep group on the 

 anterior part of the forearm. 



4. Groups of muscles, acting in harmony to discharge some one physiological 

 function, form a musculature. Adjacent musculatures are always separated by 

 septa of deep fascia. Each musculature has its own nerve-supply. Fascial septa 

 are always attached to the bone, being continuous there with the periosteum. 



APONEUROSIS. The term aponeurosis, in the plural, aponeuroses, applies to 

 dense, strong fascia, in localities where the action of the fascia is intimately asso- 

 ciated in more than a secondary manner with that of a muscle. You will find 

 the aponeurosis of the diaphragm, of the internal and external oblique and trans- 

 versalis muscles of the abdomen, the occipito-frontal aponeurosis, the lumbar, 

 pharyngeal, and vertebral aponeuroses. In these places this structure forms 

 either an integral part of the muscle itself, or constitutes the main structure in 

 the region in which it is found. The terms aponeurosis of investment and inser- 

 tion refer to the structure as forming either a cover for a muscle or its insertion. 

 A single aponeurosis may do both of these. For instance, the aponeurosis of 

 investment for the glutens maximus muscle continues downward, and the 

 muscle is aponeurotically inserted thereby into the deep fascia of the thigh. 



ORIGIN AND INSERTION OF MUSCLES. These are very arbitrary terms. 

 Usually the more fixed of two points is called the origin, the less fixed point, the 

 insertion. Insertion may be by tendon or by aponeuroses. Notice that many 

 muscles take a large part of their origin from the deep fascia investing them. 

 Attachment applies to both origin and insertion. 



ANATOMICAL FIBROUS ARCHES. You will, in the course of your reading, see 

 the above expression. The two heads of muscles are always connected by a 

 fibrous arch. The following will illustrate the point : The gastrocnemius, 

 soleus, biceps, flexor sublimis digitorum, pronator radii teres, flexor longus 

 pollicis, the biceps of the thigh. Vessels and nerves are frequently described as 

 passing under the fibrous arch of a muscle. 



THE SUPERFICIAL FASCIA 



1. Is found immediately under the skin ; 



2. It has two strata an upper and a lower ; 



3. The upper stratum contains fat the panniculus adiposus ; 



4. The lower stratum contains the cutaneous vessels and nerves ; 



5. It has no fat in the eyelids, penis, and scrotum ; 



6. It is not attached to bony eminences ; 



7. It has some muscles, called dermals ; 



8. Its local special names are cribriform and colles ; 



9. Its fat in the palms and soles is called granular fat. 



THE SEROUS MEMBRANES. You will be able to demonstrate on the cadaver 



1 . They are all related to the lymphatic system ; 



2. They form air-tight cavities, except the female peritoneum ; 



3. They are all thin and transparent ; 



4. They completely or partially invest organs ; 



5. Peritoneum, pleura, and pericardium are proper serous membranes ; 



6. The linings of blood-vessels and joints are subdivisions. 



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