228 



ANATOMY FOR NURSES 



[Chap. XII 



General 

 Circulation 



Piilmonary 

 Circulation 



SUMMARY 



Right auricle to right ventricle, then pulmonary 

 arteries to lungs. Capillary systen\. Re- 

 turn by pulmonary veins to left auricle. 



Purpose — To increase oxygen and decrease 

 carbon dioxide. 



Systemic 

 Circulation 



Factors 



Governing 



Circulation 



Heart-beat ' 



Elasticity and Exten- 

 sibility of Arterial 

 Walls 



' Left auricle to left ventricle, then by means of 



aorta and its branches to all parts of the bodj'. 



Capillary system. Return by veins which 



empty into superior and inferior venae cavse. 



Carry, and r Oxj'gen. 



give up to < Nutritive ma- 

 Purpose ^ tissues I tcrials. 



Take from tis- f Carbon dioxide, 

 sues I Waste products. 



1. The heart-beat. 



2. The elasticity and e.xtensibiUty of the arterial walls. 



3. The position and direction of the valves. 



4. The large number and small bore of the capillaries. 



5. The large size and non-contractile character of the walls 



of the veins. 



(Cardiac cycle, 72 per 

 minute. 

 Occupies 0.8 of a 

 second. 

 1. Closure of auriculo- ventricu- 

 lar valves. 

 Heart Lubb { 2. Contraction of ventricles. 



Sounds 3. Cardiac impulse against chest 



wall. 

 Dup 1. Closure of semilunar valves. 



( Power inherent in heart muscle. 

 ( Sodium. 

 Stimulated by chlorides < Potassium. 

 I Calcium. 

 Pueumogastric nerve — inhibi- 

 tory. 

 Sympathetic nerve — accelera- 

 tor. 

 Enables them to stretch and receive extra amount 



of blood. 

 Enables them to recoil and convert intermittent 



into continuous stream. 

 Arteriosclerosis = loss of elasticity and extensi- 

 biUtv. 



Cause 



Innervation • 



