120 CIRCULATION 



siderable amount is poured into the veins. A substance in 

 solution injected into the blood can be detected at the mouth 

 of the thoracic duct in from four to seven minutes. The 

 lymphatic capillaries in different regions of the body have a 

 different structure which is not optically recognizable but 

 which gives them different physiological properties, so that 

 they influence the character of the lymph formed, particularly 

 in regard to the percentage of protein. 



QUESTIONS ON CHAPTER VI 



Give the path of the blood through the body. 



Give the path of the blood through the portal system. 



What is meant by "circulation of the blood"? 



What function is fulfilled by the circulation? 



Whence does the heart derive its energy? 



Define systole and diastole. 



By what means is the blood forced in one direction only? 



What different events take place during a cardiac cycle? 



To what are the changes in the size of the heart duo? 



What is the condition of the heart when relaxed? 



What changes take place in the heart during systole when the thorax is 

 open? 



How are these changes modified in the unopened chest? 



Give the changes of color of the heart during contraction. 



Why does the heart not move from the chest wall during systole? 



Where is the apex beat felt? 



What is meant by "negative impulse"? 



Describe the sounds of the heart. 



With what portions of the cardiac cycle do they coincide? 



What is the cause of the heart sounds? 



Where can the sounds be best heard? 



Discuss the rate of the heart beat. 



Describe the character of the contractions of the auricle and ventricle. 



Give the times involved by the various events of the cardiac cycle. 



What changes take place in regard to the time occupied by the cardiac 

 cycle events when the heart rate is quickened? 



Describe the action of the valves during a heart beat. 



Discuss the venous pulse. 



What is the pulse volume? 



How is the pulse volume obtained? What is its value? 



How is the work of the heart calculated? 



How are intraventricular pressures determined? 



How much work does the heart do in a day? 



What are the relative pressures in ventricle and aorta? 



Discuss endocardiac pressure curves obtained from ventricle with different 

 methods. 



To what are the oscillations of the plateau due? 



In what way may the times of closure and opening of the valves be 

 ascertained on intracardiac pressure curves? 



Define "period of reception" and "period of ejection." 



Discuss periods of complete closure of the ventricles. 



Can the ventricles alone maintain circulation? 



