. The animans and man; an elementary textbook of zoology and human physiology. this we have alreadyfound in the case of themuscles of the heart andarteries. Such also arethe muscles of theoesophagus, stomach andintestines. Muscles ofthis type have been calledinvoluntary muscles be-cause they are regula-ted by the nervous sys-tem without any controlof the will. Under themicroscope these mus-! cles present no appear-ance of striations and soFIG. 174. Deep view of muscles and ten- have been called non-stri- dons of right shoulder. A, brachialis (jf^d muscles anticus; B, tendon of insertion of bi-
. The animans and man; an elementary textbook of zoology and human physiology. this we have alreadyfound in the case of themuscles of the heart andarteries. Such also arethe muscles of theoesophagus, stomach andintestines. Muscles ofthis type have been calledinvoluntary muscles be-cause they are regula-ted by the nervous sys-tem without any controlof the will. Under themicroscope these mus-! cles present no appear-ance of striations and soFIG. 174. Deep view of muscles and ten- have been called non-stri- dons of right shoulder. A, brachialis (jf^d muscles anticus; B, tendon of insertion of bi- „, ceps (biceps removed); C,coracoid pro- B1°°d and nerve SUP cess of scapula; ci, clavicle; H, ply.—Since every muscle humerus; Sc, scapula with attached Qf £ne foody must be wellsubscapularis muscle. T-T, triceps. ,. , (After Allen Thomson.) supplied with nutriment and oxygen for its meta-bolism and for the work it performs, all muscles of thebody are richly supplied with blood capillaries. These pene-trate the connective tissues that separate the muscle B THE SKELETON AND MUSCLES 341 To each muscle also a nerve passes, distributing its nervefibers through the connective tissues to the muscle its nerve-supply, any muscle would be useless,for the nerve centers must initiate and control every motion. Hygiene of muscles; necessity for exercise.—Muscularactivity is absolutely essential to healthy living, and shouldtherefore be as much a daily habit as eating or a vigorous walk for a mile or two and note the day may be cold, but the body is soon aglow withwarmth, the heart beats more vigorously, the breathing isdeep and invigorating. What is taking place in the body?The muscles are undergoing chemical change. Carbondioxide and other wastes are being thrown into the blood,and large quantities of heat are being liberated so that thetemperature of the body rises considerably. This callsfor a rapid supply of blood to the muscle
Size: 1103px × 2264px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookd, booksubjectphysiology, booksubjectzoology
