GLANDIFORM BODIES CONNECTED WITH RESPIRATORY AFPARaTUS. 5^^3 



and tlif lungs are the- hroiichi ; the right brouchus is the sliortest nml widest, and has an altndst 

 hnriziMital diri-cticin, entering the right lung at the fourth dorsal vertebra; the left is longer 

 and less vdlumiudun, and reaches the corresponding lung at tiio til'tli vertebra. 



4. Lungs.' The lungs weigh about forty ounces. As in all imiraals, the right is more 

 vnliiininous than thn left, and is divided into three lobes; the latter has only two. The 

 inferior vena cava is not surrounded by pulmonary tislue : the principal lobes are partitioned 

 into lobules, which are visible on the surlace, and ou the limits of which are deposited, only in 



Fig. 333. 



LUNG OP THE SHEEP (INFERIOR VIEW). 



1, Right luug; 2, left lung; 3, trachea; 

 4, heart ; 5, carotid arteries ; 6, posterior 

 vena cava. 



HUMAN LUNGS AND HEART (FRONT VIEW). 



1, Right ventricle; 2, left ventricle; 3, rii;ht auricle; 

 4, left auricle ; n. ]iulmnnary arterv ; 6, riirht pul- 

 monary arteiy; 7, left pulmonary arterv; 8, liga- 

 ment of ductus arteriosus; 9, arch of aorta; 10, 

 superior vena cava ; 11, arteria innominata ; 12, right 

 subclavian vein, with the artery behind it ; 13, right 

 common carotid artery and vein; 14, left vena in- 

 nominata; 15, left carotid artery and vein; 16, left 

 subclavian vein and artery; 17, trachea; 18, right 

 bronchus; 19, left bronchus; 20, 20, pulmonary 

 veins; 21, superior lobe of right lung; 22, middle 

 lobe ; 23, inferior lobe ; 24, superior lobe of left lung ; 

 25, inferior lobe. 



the adult, a notable quantity of pigmentary matter, that gives the lungs the appearance of a 

 chess-board. There is nothing to be said respecting their internal conformation and structure. 



The Glandiform Bodies connected with the Respiratory 



Apparatus. 



1. Thyroid Body, or Glaot) (Fig. 334). 



The thyroid hodij consists of two oval lobes of a reddish-brown colour, 

 and is situated close to, and behind, the larynx, beside the two first rings of the 

 trachea. 



These two lobes, distinguished as right and left, appear at first sight to be 

 perfectly independent ; but close examination shows them to be united by an 

 intermediate portion (the isthmus), which passes across the anterior face of the 



