Give the term/reason a.Mechanism responsible for parturition. b.Role of oxytocin during expulsion of the baby out of uterus. c.Why do pellucida block the entry of additional sperm? d.Sperms cannot reach ovum without seminal plasma. e. All copulations do not lead to fertilization and pregnancy. or Describe various natural methods of contraception in human beings.
Answers
Answer:
Solution :
a.Foetal Ejection Reflex
b.Oxytocin acts on the uterine muscles and causes stronger uterine contractions.
c.To enable one egg to be fertilized by a single sperm.
c.Sperms with seminal plasma form the semen. Without the secretions, sperm cannot mature and have motility to reach the egg.
e.Copulation depends on the presence of egg in the ampullary isthmic junction. For fertilization to occur both sperms and egg needs to be transported simultaneously. Hence not all copulations lead to fertilization and pregnancy.
Describe various natural methods of contraception in human beings.
Natural methods
Periodic abstinence
Withdrawal
Lactational amenorrhea
Periodic abstinence: Couple avoid or abstain from coitus from days 10-17 of the menstrual cycle when ovulation is expected as the period is very fertile for conception.
Withdrawal or Coitus interruptus: The male partner withdraws his penis from the vagina just before the ejaculation of the semen to avoid insemination.
Lactational amenorrhoea: During lactational period, after parturition, there would be a period where no ovulation occurs and hence no menstruation. Such a period is called lactational amenorrhea and is considered to be a safe period.