AND PHYSIOLOGY. 



119 



242. Biceps.— The Biceps 

 (two heads, or points of at- 

 tachment) is the muscle which 

 flexes or bends the arm to- 

 wards the body. It arises 

 from the head of the humerus 

 and scapula, and is inserted 

 into the upper end of the 

 radius. It is a very fine ex- 

 ample of a fusiform muscle, 

 and though acting at a great 

 mechanical disadvantage as to 

 power, it effects a rapid move- 

 ment. 



243. Triceps.— The Tri- 

 ceps (three heads), its antag- 

 onist, is similar in its general 

 form, and is attached to the 

 ulna instead of the radius. 

 It is situated upon the poste- 

 rior side of the humerus, and 

 the force with which it may 

 be made to contract, is seen 

 in the powerful blow given 

 by the boxer, or the weights 

 raised by extending the arms 

 upon the instrument made for 

 the purpose in a gymnasium. 



244. Muscles of the Fore- 

 Arm.— The Fore- Arm is abun- 



dinous Insertion of the Pectoralis Minor. 



the Biceps. 13, Latissimus Dorsi. It, Inner portion of the Triceps. 15, Body of the 

 Eiceps. 16, Outer portion of the Triceps. 17, Brachials Interims. 18, Origin of the 

 Flexor Muscles. 19, Brachialis Internus near its Insertion. 20, Tendon of the Biceps. 

 21, Fasciculus from the Biceps Tendon to the Fascia Brachialis. 22, Flexor Carpi Ea- 

 dialis. 23, Palmaris Longus. 24, Supinator Radii Longus. 



242. Why is the name Biceps given to the muscle that flexes the fore-arm ? What 

 mechanical disadvantage in its structure ? What gain from it? 213. What is the antag- 

 onist of the Biceps ? What actions show its mode of action ? 



A View of the Muscles on the Front of 

 the Arm. 1, Clavicle. 2, Coracoid Pro 

 cess and Origin of tho Short Head of the 

 Biceps. 3, Acromion Scapulas. 4, Head 

 of the Os Humeri. 5, Tendon of the Bi- 

 ceps Muscle in the Bicipital Groove. 6, 

 Ligamentum Adscititium dissected off. 7, 

 Cut portion of the Pectoralis Major. 8> 

 Long Head of the Biceps. 9, Insertion of 

 the Deltoid. 10, Cut portion of the Ten- 

 11, Coraco-Brachialis. 12, Short Head of 



