QUESTIONS 257 



How long does menstruation last? What are the symptoms accompany- 

 ing it? 



Give the physiological causes of menstruation. 



Discuss puberty, 



What is the menopause? 



What is the object of menstruation? 



What is the relation of ovulation to menstruation? 



How do spermatozoa reach the Fallopian tubes? 



How many types of fetal circulation are there? 



Describe the placental circulation. 



What changes take place in fetal circulation at birth? 



What is the length of the period of gestation in the human being? From 

 what time does it probably date? 



What is the earliest sign of pregnancy? 



What is the cause of the expulsion of the fetus from the uterus? 



Discuss the occurrence of twins. 



Discuss the determination of sex. 



Is the production of sex self-regulating? 



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