Tag: fertilization and post fertilization in humans

Questions Related to fertilization and post fertilization in humans

Select the correct statement.

  1. hPL plays a major role in parturition.

  2. Fetus shows movements first time in the ${7}^{th}$ month of pregnancy.

  3. Signal for parturition comes from fully developed fetus and placenta.

  4. Embryo's heart is formed by the ${2}^{nd}$ month of pregnancy.


Correct Option: C
Explanation:

Parturition, also called birth or childbirth, process of bringing forth a child from the uterus, or womb. The prior development of the child in the uterus is described in the article human embryology. The process and series of changes that take place in a woman’s organs and tissues as a result of the developing fetus are discussed in the article pregnancy. Parturition is induced by a complex neuroendocrine mechanism. The signals for parturition originate from the fully-developed foetus and the placenta which requires the release of oxytocin from the posterior lobe of the maternal pituitary.

So the correct option is 'signal for parturition comes from fully developed foetus and placenta'.

Corpus luteum develops from

  1. Oocyte

  2. Nephrostome

  3. Graafian follicle

  4. None of the above


Correct Option: C
Explanation:

After ovulation the lining of the (graafian) follicles grow inward, forming corpus luteum (yellow body), which temporary function as endocrine tissue. It secrete estrogen and progesterone, which stops additional ovulation, and thickening of uterine wall. If pregnancy does not occur within 14 days corpus luteum degenerates and menstruation follows.

Gestation period is the duration

  1. Of fertilization

  2. Between egg growth and ovulation

  3. Between fertilization and parturition

  4. None of the above


Correct Option: C
Explanation:
The gestation period is the duration between fertilization and parturition. Gestation period is the time in which a foetus develops, beginning with fertilization and ending at birth.
Fertilization is the process of fusion of two types of gametes (spermatozoon and ovum), so as to form a diploid zygote.
Parturition is the act of expelling the full term young ones from the mother's uterus at the end of gestation.

Gestation period in human beings is about 

  1. 10 weeks

  2. 28 weeks

  3. 32 weeks

  4. 36 weeks


Correct Option: D
Explanation:

Gestation (pregnancy) is completed in about 266 days from the mother's last menstruation. The gestation period of human beings is 270 days to 280 (approximately). It is usually about 266 days i.e., 36 weeks.

The process of delivery of the feotus is called 

  1. Parturition

  2. Implantation

  3. Fertilisation

  4. Lactation

  5. Ovulation


Correct Option: A
Explanation:

Parturition can be defined as the act of expelling the full term young ones from the mother's uterus at the end of the gestation period. In other words, the process of delivery of the fetus is known as parturition.

Delivery of developed foetus is

  1. Ovulation

  2. Oviposition

  3. Parturition

  4. Abortion


Correct Option: C
Explanation:

The delivery of the developed foetus after 9 months is known as parturition. Ovulation is the release of the secondary oocyte from the ovary. 

Oviposition is known as the egg-laying stage.
Abortion is the ending of the pregnancy before time. If it is abrupt then it is known as a miscarriage but if the abortion is surgical and through pills, it is known as induced abortion.
So, the correct option is 'Parturition'.

Thick yellow, high protein fluid produced by mammary glands of a woman during first $2-3$ days after child birth is

  1. Meconium

  2. Hymen

  3. Cumulus oophorus

  4. Colostrum


Correct Option: D
Explanation:
The mammary glands undergo differentiation during pregnancy and start producing milk towards the end of pregnancy by the process called lactation.
The milk produced during the initial few days of lactation – colostrum. It is thick and yellow in colour. It contains several antibodies essential to develop resistance for new-borns.
so, the correct option is 'Colostrum'.

State whether the following statements are true or false.
Prolactin stimulates milk secretion and growth of breast.

  1. True

  2. False


Correct Option: A
Explanation:
Prolactin regulates the growth of the mammary glands and formation of milk in them. Prolactin has a wide variety of effects. It stimulates the mammary glands to produce milk (lactation). Increased serum concentrations of prolactin during pregnancy cause enlargement of the mammary glands and prepare for milk production.
So, the correct option is 'True'.

Breast feeding suspends pregnancy due to

  1. Post pregnancy lower levels of FSH and LH

  2. Post pregnancy higher levels of FSH and LH which puts a negative check on ovulation

  3. Inhibiting the release of FSH by prolactin and thus countering the effects of FSH on the ovarian follicles

  4. Increasing the release of inhibin by prolactin and thus countering the effects of FSH on the ovarian follicles


Correct Option: C
Explanation:

The hypothalamus secretes the Gonadotropin-releasing hormone which is responsible for menstruation sequence. The GnrRH repressed by the prolactin hormone, which encourages the production of milk. Without the GnRH release, the menstrual cycle wont begin a new event of pregnancy.

As long as prolactin level are high, GnRH generally won't be release. Now GnRH is responsible for the release of the follicular stimulating hormone. The hormone FSH is responsible for the formation of ovarian follicle. So, as GnRH is stopped there will be an inhibition in the release of FSH by prolactin and thus thus it counter the effects of FSH on the ovarian follicle. So, there will be a delay in ovulation that will automatically prevent pregnancy. 
So, the correct option is 'Inhibiting the release of FSH by prolactin and thus countering the effects of FSH on the ovarian follicle'.

Which of these is not an important component of the initiation of parturition in humans?

  1. Synthesis of prostaglandins

  2. Release of oxytocin

  3. Release of prolactin

  4. Increase in estrogen and progesterone ratio


Correct Option: C
Explanation:

  • Parturition is a phenomenon of giving birth. It is a process of delivering a child from the womb to the outside. It is usually initiated by the release of oxytocin hormone. 
  • This hormone increases the contraction of uterine muscles. Prostaglandins are synthesized and released in response to the oxytocin hormone. Also, an increase in estrogen and progesterone ratio indicates the initiation of the parturition process. 
  • Prolactin hormones are released after the parturition in order to secrete the milk from the mammary gland.

Thus, the correct answer is 'Release of prolactin.'