472 RESPIRATION 



accurate classification of the muscles which take part in the expansion 

 of the lungs. The following table, however, may serve as a general 

 guide. 



A. Inspiration. 



1. Normal. 



Diaphragm (nerv. phrenicus). 



Muse, intercost. externi et intercartilaginei (nerv. intercostales). 



2. Forced. 



a. Muscles of the Trunk. 



Muse, sealeni (nerv. plex. cerv. et brachialis). 



Muse, serratus posterior superior (nerv. intercostales). 



Muse, serratus anterior magnus (nerv. thor. longus). 



Muse, pectoralis major et minor (nerv. thor. ant.). 



Muse, sternoeleidomastoideus (nerv. accessor!). 



Muse, trapezius (nerv. accessorii). 



Muse, extensores columnae vertebralis (ram. post. nerv. dors.). 



Muse, rhomboidei (nerv. dors, scapulae). 



Muse, levator scapulae (nerv. dors, scapulae). 

 6. Larynx. 



Muse, sternohyoideus (nerv. ram. disc, hypoglossi). 



Muse, sternothyreoideus (nerv. ram. disc, hypoglossi). 



Muse, erieoarytenoideus (nerv. lar. inferior). 



c. Pharynx. 



Muse, levator veli palatini (nerv. facialis). 



Muse, azygos uvulae. 



Muse, constrictores pharyngis (nerv. glossoph. et vagus). 



d. Face. 



Muse. dil. narium ant. et post. (nerv. facialis). 

 Muse, levator alae nasi (nerv. facialis). 



B. Expiration. 



1. Normal. 



Gravity and elastic recoil of the lungs, intercostal cartilages and a,bd. 

 muscles. 



2. Forced. 



Muse, intercostales intemi (nerv. intercostales). 



Muse, abdominales. 



Muse, triangularis sterni (nerv. intercostales). 



Muse, serratus post, inferior (ram. ext. nerv. dors.). 



Muse, quadratus lumborum (ram. muse, e plexa lumbali). 



CHAPTER XXXVIII 



THE FREQUENCY AND CHARACTER OF THE RESPIRA- 

 TORY MOVEMENTS 



Methods of Recording the Respiratory Movements. — The early 

 measurements of the diameter, of the thorax made with the help of a 

 tape-measure and large calipers, were soon superceded by the registra- 

 tion of the movements of the chest by means of levers placed horizon- 

 tally upon its external surface,^ or by means of an instrument 



^Vierordt and Ludwig, Arch, fiirphysiol. Heilkunde, xiv, 1855, 253, and Riegel, 

 Die Athembewegungen, Wiirzburg, 1873. 



