Question:
Effects of estrogens at the time of parturition include
(A). Direct effect upon the myometrium, increasing its responsiveness to oxytocin
(B). Softening of the cervix by altering the structure of collagen fibers
(C). Softening and relaxation of pelvic ligaments
(D). Stimulation of the production and release of prostaglandin F2\(\alpha\)
Choose the correct answer from the options given below:
Effects of estrogens at the time of parturition include
(A). Direct effect upon the myometrium, increasing its responsiveness to oxytocin
(B). Softening of the cervix by altering the structure of collagen fibers
(C). Softening and relaxation of pelvic ligaments
(D). Stimulation of the production and release of prostaglandin F2\(\alpha\)
Choose the correct answer from the options given below:
(A). Direct effect upon the myometrium, increasing its responsiveness to oxytocin
(B). Softening of the cervix by altering the structure of collagen fibers
(C). Softening and relaxation of pelvic ligaments
(D). Stimulation of the production and release of prostaglandin F2\(\alpha\)
Choose the correct answer from the options given below:
Show Hint
To remember the roles of hormones at parturition:
- Estrogen: Sensitizes the uterus to oxytocin, softens the cervix, and stimulates PGF2\(\alpha\) release.
- Relaxin: Specifically relaxes the pelvic ligaments.
- Estrogen: Sensitizes the uterus to oxytocin, softens the cervix, and stimulates PGF2\(\alpha\) release.
- Relaxin: Specifically relaxes the pelvic ligaments.
Updated On: Aug 3, 2026
- (A) and (B) only.
- (A), (B) and (C) only.
- (A), (B) and (D) only.
- (B), (C) and (D) only.
Show Solution
Verified By Collegedunia
The Correct Option is C
Solution and Explanation
Step 1: Understanding the Concept:
Parturition is initiated by a complex cascade of endocrine events.
Near the end of gestation, a rise in fetal cortisol triggers a shift in placental steroidogenesis, causing progesterone levels to fall and estrogen levels to rise.
Step 2: Detailed Explanation:
Let us analyze the physiological effects of estrogen during parturition:
- Myometrial sensitization (A): Estrogen directly stimulates the synthesis of oxytocin receptors in the myometrium, significantly increasing its responsiveness and sensitivity to oxytocin-induced contractions. Thus, (A) is correct.
- Cervical Softening (B): Estrogen alters the extracellular matrix of the cervix, promoting collagenase activity that breaks down collagen fibers to soften and dilate the cervix. Thus, (B) is correct.
- Prostaglandin Synthesis (D): Estrogen upregulates cyclooxygenase enzymes in the endometrium, directly stimulating the synthesis and release of prostaglandin F2\(\alpha\) (PGF2\(\alpha\)), which is essential for luteolysis and myometrial contraction. Thus, (D) is correct.
- Evaluating Statement (C): While pelvic ligament relaxation occurs at parturition, this effect is primarily mediated by the hormone relaxin.
Estrogen plays a secondary, priming role rather than being the primary driver of ligament relaxation.
Therefore, statements (A), (B), and (D) are direct primary effects of estrogen during parturition.
Step 3: Final Answer:
The direct effects of estrogen include (A), (B), and (D). This corresponds to option (C).
Parturition is initiated by a complex cascade of endocrine events.
Near the end of gestation, a rise in fetal cortisol triggers a shift in placental steroidogenesis, causing progesterone levels to fall and estrogen levels to rise.
Step 2: Detailed Explanation:
Let us analyze the physiological effects of estrogen during parturition:
- Myometrial sensitization (A): Estrogen directly stimulates the synthesis of oxytocin receptors in the myometrium, significantly increasing its responsiveness and sensitivity to oxytocin-induced contractions. Thus, (A) is correct.
- Cervical Softening (B): Estrogen alters the extracellular matrix of the cervix, promoting collagenase activity that breaks down collagen fibers to soften and dilate the cervix. Thus, (B) is correct.
- Prostaglandin Synthesis (D): Estrogen upregulates cyclooxygenase enzymes in the endometrium, directly stimulating the synthesis and release of prostaglandin F2\(\alpha\) (PGF2\(\alpha\)), which is essential for luteolysis and myometrial contraction. Thus, (D) is correct.
- Evaluating Statement (C): While pelvic ligament relaxation occurs at parturition, this effect is primarily mediated by the hormone relaxin.
Estrogen plays a secondary, priming role rather than being the primary driver of ligament relaxation.
Therefore, statements (A), (B), and (D) are direct primary effects of estrogen during parturition.
Step 3: Final Answer:
The direct effects of estrogen include (A), (B), and (D). This corresponds to option (C).
Was this answer helpful?
0
0
Top ICAR AIEEA Veterinary Science Questions
- In ox vallate papillae are
- Spiral colon is characteristic of
- Assertion (A) : Stratum lucidum is translucent layer present between stratum spinosum and stratum granulosum
Reasoning (R) : Stratum lucidum is translucent due to presence of eledin protein.
In light of the above statements, choose the correct answer from the options given below. - Statement (I): Keratinocytes contain melanin pigment in the form of melanosomes.
Statement (II): Melanin pigment is produced by keratinocytes with the help of Tyrosinase enzyme.
In light of the above statements, choose the most appropriate answer from the options given below. - Which of the following is true for mast cells?
(A). These cells are common in loose connective tissue.
(B). These cells take metachromatic stain.
(C). These cells are rich in histamine, heparin and proteases.
(D). These cells contain basophilic cytoplasmic granules.
Choose the correct answer from the options given below:
View More Questions
Top ICAR AIEEA Reproduction in Animals Questions
- Which of the following species has cotyledonary placenta?
- Match List-I with List-II
List-I
(A). FSH
(B). $\text{PGF}_{2\alpha}$
(C). GnRH
(D). eCG
List-II
(I). Placenta
(II). Hypothalamus
(III). Uterus
(IV). Pituitary
Choose the correct answer:} - In stallion, testosterone is produced by
- The hormone that is primarily responsible for the onset of ovarian activity and puberty, in animals is
- Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A) : In cows, insemination should be preferably done a few hours before the ovulation.
Reason (R) : Sperm capacitation and acrosomal reaction in the genital tract of cow may take about six hours.
In light of the above statements, choose the correct answer from the options given below
View More Questions
Top ICAR AIEEA Questions
- Which of the following statements is false?
- Which of the following is an example of an inventory?
- According to Adam Smith, productivity gains could be brought about through .
- The supply curve for an artificially scarce good is .
- Which of the following would not be considered an opportunity cost of paid employment?
View More Questions