422 



LABORATORY MANUAL OF HUMAN ANATOMY 



In the ascending aorta, study from the outside 



(a) Bulb of aorta (bulbus aortae). 



.(b) Sinuses of aorta (sinus aortae [Valsalvae]) . 



(c) Coronary arteries of heart (Aa. coronariae [cordis]). 



The distribution of these arteries has already been studied. 



FIG. 215. 



A. carotia interna 



The five paired / 

 branchial arte-<( 

 rial arches \ 



Truncus arteriosus - 



Aorta descendens 



A. carotisr 



eommuniS' 



d extra 



A. anonyma- 



Ramus dexter 



A. pulmonalis' 



A. vertebralis. 



dextra 



A. pulmonalis ' 

 Aorta ascendens 



Aa. carotides externae, dextra, 

 et sinistra 



A. carotis interna 

 sinistra 



Arcus aortae 



Ductus arteriosus 

 Ramus sinister 

 ,A. pulmonalis 



A. vertebralis 

 sinistra 



A. subclavia sinistra 

 -- Aorta descendens 



Diagrams of the transformation in the arteries of the branchial arches : A, original, B, persistent 

 disposition of the arterial stems (Rathke's schema with a slight alteration according to F. Hoch- 

 stetter.) (After Toldt, Anat. Atlas, Wien, 1901, 2 Aufl., p. 563, Fig. 938.) 



In connection with the arcus aortae, studyats exact relations, 

 note the isthmus aortae at its junction with the aorta descendens, 

 and dissect out and study thoroughly the following great arterial 

 trunks : 



(a) Innominate artery (A. anonyma}. 



(aa) Lowest thyreoid artery (A. thyreoidea ima), inconstant. 



(b) Left common carotid artery (A. carotis communis sinistra). 



(c) Left subclavian artery (A. subclavia sinistra). 



The thoracic part of the aorta descendens will be studied 

 later on. 



Cardiac Plexus (Plexus cardiacus) . 



The superficial portion of this plexus has already been 

 studied. Its deeper portion should next be examined. Place two 

 ligatures about the arcus aortae at its junction with the aorta 

 descendens and divide the aorta between them ; similarly ligate 

 twice and divide between at the junction of the arcus aortae with 

 the aorta descendens. Cut through the V. cava superior, just 

 below the entrance into it of the V. azygos. Divide the liga- 



