NEET-PG 2015 Practice Questions

Q: Cephalic index is calculated as

Biparietal Diameter / Occipitofrontal Diameter. ***Biparietal Diameter / Occipitofrontal Diameter*** - The **cephalic index** is a measure used in **craniometry** to describe the shape of the skull, calculated by dividing the maximum **biparietal diameter** (width) by the maximum **occipitofrontal diameter** (length) and multiplying by 100. [1] - This ratio helps classify head shapes into **brachycephalic** (short, wide), **mesocephalic** (medium), and **dolichocephalic** (long, narrow). *Biparietal Diameter / Head Circumference* - This ratio is not the standard definition for the **cephalic index**; head circumference is a measure of overall head size, not its proportional shape in terms of width to length. - While both parameters are used in fetal biometry, their ratio does not define the **cephalic index**. *Head Circumference / Femur Length* - This ratio is completely unrelated to the **cephalic index**. - **Head circumference** estimates head size, and **femur length** estimates fetal long bone growth, both used for gestational age assessment, but not for skull shape. *Occipitofrontal Diameter / Biparietal Diameter* - This formula represents the inverse of the **cephalic index**, which would yield a different and non-standard index for skull shape. - The traditional and medically recognized formula for the **cephalic index** places the **biparietal diameter** in the numerator.

Q: Number of stem villi at term in human placenta is?

240. ***240*** - At term, the **human placenta** contains numerous **stem villi** which branch extensively to form the villous tree. - The approximate number of **stem villi** at term is around **240**, contributing to the large surface area for maternal-fetal exchange. *60* - This number is significantly **lower** than the actual count of **stem villi** found in a mature, term placenta. - Such a low number would result in an **insufficient surface area** for effective nutrient and gas exchange. *120* - While higher than 60, this number is still **underestimated** for the quantity of **stem villi** present in a full-term human placenta. - A placenta with only 120 stem villi might not be able to adequately support a fetus at term. *480* - This number is an **overestimation** of the typical count of **stem villi** in a human placenta at term. - While villi are extensive, 480 stem villi represent a significantly higher number than usually observed.

Q: Which of the following is NOT typically associated with Kallmann's syndrome?

Excess stimulation of the HPO axis. ***Excess stimulation of the HPO axis*** - Kallmann's syndrome is characterized by **hypogonadotropic hypogonadism**, meaning there is a deficiency in the secretion of **gonadotropin-releasing hormone (GnRH)** [1] from the hypothalamus. - This deficiency leads to *reduced* stimulation of the **hypothalamic-pituitary-ovarian (HPO)** axis, not excess stimulation. *Amenorrhea* - **Amenorrhea** (absence of menstruation) is a common presentation in females with Kallmann's syndrome due to the **hypogonadotropic hypogonadism**. - The lack of GnRH results in insufficient **follicle-stimulating hormone (FSH)** and **luteinizing hormone (LH)**, preventing ovarian function and regular menstrual cycles. *Hypogonadotropic hypogonadism* - This is a **defining feature** of Kallmann's syndrome, where the **hypothalamus fails to produce enough GnRH**, leading to low levels of FSH and LH from the pituitary. - The low gonadotropin levels subsequently cause the gonads (testes or ovaries) to produce insufficient sex hormones, resulting in **delayed or absent puberty** [1]. *Anosmia* - **Anosmia** (the inability to smell) is a classic and diagnostic feature of Kallmann's syndrome, distinguishing it from other forms of hypogonadotropic hypogonadism. - It occurs because the **GnRH-producing neurons** originate in the olfactory placode and fail to migrate correctly into the hypothalamus during embryonic development, disrupting both smell and GnRH secretion.

Q: A pregnant woman at term presents with a symphysiofundal height of 40 cm. What is the most likely approximate fetal weight?

4 kg. ***4 kg*** - Using **Johnson's formula** for fetal weight estimation: Weight (g) = (SFH in cm - n) × 155, where n = 12 if fetal vertex is above ischial spines or n = 11 if at/below spines - For SFH of **40 cm**: (40 - 12) × 155 = **4,340 g ≈ 4 kg** or (40 - 11) × 155 = 4,495 g ≈ 4.5 kg - An approximate weight of **4 kg** is the most reasonable estimate for an SFH of 40 cm at term - This represents a larger than average fetus, which is consistent with the clinical measurement *3 kg* - While 3 kg is a common average birth weight, Johnson's formula calculation for an SFH of **40 cm** yields a significantly higher estimate - A weight of 3 kg would typically correlate with an SFH of approximately **32-33 cm**, not 40 cm - This option significantly underestimates the fetal weight for the given measurement *3.3 kg* - Although closer to average birth weight, this still **underestimates** the fetal weight suggested by an SFH of 40 cm - Using Johnson's formula, this measurement would correlate with an SFH of approximately **34-35 cm**, not 40 cm - The 40 cm measurement indicates a larger fetus than this estimate suggests *4.3 kg* - This represents the more **precise calculation** using Johnson's formula: (40 - 12) × 155 = 4,340 g - While mathematically accurate, **4 kg is the more commonly used approximation** in clinical practice for ease of communication - Both 4 kg and 4.3 kg are acceptable estimates, but 4 kg is the standard teaching answer for NEET-PG

Q: What is the primary hormonal cause of hot flushes experienced during menopause?

Decreased estrogen levels. ***Decreased estrogen levels*** - **Decreased estrogen** is the primary hormonal change during menopause, leading to thermoregulatory dysfunction in the hypothalamus. - This hormonal imbalance causes the **vasomotor symptoms** like hot flushes and night sweats. *Increased noradrenaline* - While **noradrenaline** (norepinephrine) is involved in thermoregulation, its increase is a **secondary event** triggered by the initial estrogen deficiency, not the primary cause. - Increased noradrenaline can exacerbate the **vasodilation** and heat dissipation experienced during a hot flush. *Increased noradrenaline with normal estrogen levels* - This option is incorrect because hot flushes are characteristic of menopause, which is defined by **decreased estrogen levels**. - **Normal estrogen levels** would typically prevent the severe thermoregulatory instability that causes hot flushes. *Both increased noradrenaline and decreased estrogen levels* - Although both factors are involved, the question asks for the **primary hormonal cause**. **Decreased estrogen** initiates the cascade of events, including the subsequent alteration of neurotransmitter levels like noradrenaline. - Noradrenaline's role is more of a **mediator** in the physiological response to the primary estrogen deficiency.

Q: What is the recommended dose of folic acid for a patient with a history of neural tube defect (NTD) in a previous pregnancy?

4 mg. ***4 mg*** - For women with a prior history of a **neural tube defect (NTD)-affected pregnancy**, a higher dose of **4 mg of folic acid daily** is recommended to significantly reduce the risk of recurrence. - This increased dosage is crucial for achieving adequate maternal folate levels to prevent NTDs, starting at least one month before conception and continuing through the first trimester. *0.5 mg* - This dose is lower than the standard recommendation for women without a history of NTDs and is insufficient for high-risk individuals. - Suboptimal folic acid levels can still lead to a higher risk of NTD recurrence in patients with a history of NTD-affected pregnancies. *1 mg* - While 1 mg is higher than the general recommendation, it is still insufficient for women with a **history of NTD in a previous pregnancy**. - Current guidelines suggest a significantly higher dose for secondary prevention due to altered folate metabolism or higher requirements in these individuals. *2 mg* - This dose is also lower than the **established recommendation for high-risk women** who have had a previous NTD-affected pregnancy. - It does not provide the optimal level of protection required to reduce the risk of recurrence effectively.

Q: A G2P1L1 female presents at 28 weeks of gestation with a 1:4 anti-D titre. What is the most appropriate management option?

MCA Doppler. ***MCA Doppler*** - The presence of anti-D antibodies in a pregnant woman indicates **Rh isoimmunization**, which can lead to **hemolytic disease of the fetus and newborn (HDFN)**. - Even though a titre of **1:4 is below the critical threshold** (usually 1:16 or 1:32), any detectable anti-D titre at 28 weeks warrants **fetal surveillance** to detect early signs of fetal anemia. - **Middle cerebral artery (MCA) Doppler** is the **non-invasive gold standard** for detecting fetal anemia by measuring peak systolic velocity (PSV), which increases in anemic fetuses due to hyperdynamic circulation. - Serial MCA Doppler monitoring allows timely intervention if fetal anemia develops, avoiding unnecessary invasive procedures. *Caesarean section* - This is a mode of delivery and would only be considered if there were severe **fetal compromise** or other obstetric indications after proper monitoring and management. - At 28 weeks gestation with a low anti-D titre, immediate delivery is **not indicated** and would result in significant prematurity risks. *Induction of labour* - Induction of labour is a delivery method that would only be planned at term or for specific indications like severe fetal compromise unresponsive to other interventions. - At **28 weeks gestation**, the focus should be on **monitoring and prolonging pregnancy** while ensuring fetal wellbeing, not on delivery. *Amniocentesis* - Historically used to assess **bilirubin levels (ΔOD450)** in amniotic fluid as an indirect measure of fetal hemolysis, but it is an **invasive procedure** with risks (miscarriage ~1%, infection, worsening sensitization). - **MCA Doppler has largely replaced amniocentesis** for initial and serial assessment of fetal anemia due to its non-invasive nature, high sensitivity, and ability to be repeated safely.

Q: Which of the following is true regarding precocious puberty:

Sexual maturity is attained early. ***Sexual maturity is attained early*** - **Precocious puberty** is defined by the development of secondary sexual characteristics significantly earlier than the average age. - This early onset of puberty means that affected individuals reach **sexual maturity** at a younger chronological age. *Mental function is increased* - Precocious puberty does not inherently lead to an increase in **mental function** or cognitive abilities. - While hormonal changes can influence mood and behavior, they do not enhance intelligence. *Reproductive function is absent* - Precocious puberty implies the premature activation of the **hypothalamic-pituitary-gonadal axis**, leading to the appearance of secondary sexual characteristics and, in many cases, the potential for **reproductive function**. - Girls, for example, can experience early menarche and boys can produce sperm, meaning fertility is not absent but rather accelerated. *Body proportions remain unchanged* - Precocious puberty often results in changes in **body proportions**, particularly due to the early closure of epiphyseal plates. - Although there is an initial growth spurt, the premature fusion of growth plates can lead to a shorter-than-average adult height.

Q: The role of human placental lactogen is :

Supports fetal growth and development.. ***Supports fetal growth and development.*** - Human placental lactogen (hPL) acts as a **growth hormone** for the fetus, primarily by altering maternal metabolism to favor fetal nutrient supply. - It increases **maternal insulin resistance**, leading to higher maternal glucose and free fatty acids, which are then shunted to the fetus, supporting its growth and development. *Stimulate milk production* - **Prolactin**, secreted by the anterior pituitary, is the primary hormone responsible for stimulating milk production (lactogenesis). - While hPL has some structural similarity to growth hormone and prolactin, its primary role is not to directly stimulate milk production during pregnancy; rather, it prepares the breasts. *Promotes growth of breast for lactation.* - hPL, along with **estrogen** and **progesterone**, contributes to the **mammary gland development** during pregnancy, preparing the breasts for lactation. - However, its direct role is more about **mammary gland proliferation and differentiation** rather than initiation of milk production. *Provide fetal nutrition by antagonizing the action of insulin in maternal circulation, breakdown of fats and proteins and transport of fatty acids and amino acids from maternal to fetal circulation.* - This is a highly detailed and largely accurate description of *how* hPL supports fetal growth and development, making it a mechanism rather than the primary, concise role. - It describes the metabolic changes induced by hPL, which ultimately lead to the **support of fetal growth and development**.

Q: Antimullerian hormone is secreted by ?

Both Sertoli cells and granulosa cells. ***Both Sertoli cells and granulosa cells*** - **Antimullerian hormone (AMH)** is produced by **Sertoli cells in males** and **granulosa cells in females** - In **males**: Sertoli cells secrete AMH during fetal development to cause **regression of Müllerian ducts** (which would otherwise develop into uterus, fallopian tubes, and upper vagina) - In **females**: Granulosa cells of developing ovarian follicles secrete AMH, which serves as a **marker of ovarian reserve** and inhibits excessive follicle recruitment - This is the only option that correctly identifies both cell types that produce AMH *Theca cells* - Theca cells are found in ovarian follicles and produce **androgens** (androstenedione and testosterone), not AMH - These androgens are converted to estrogens by granulosa cells via aromatase enzyme - Theca cells do not produce antimullerian hormone *Leydig cells* - Leydig cells are located in the **testes** and produce **testosterone** - They do not produce antimullerian hormone - Only Sertoli cells (not Leydig cells) produce AMH in males *None of the above* - This is incorrect because AMH is indeed produced by specific cell types: **Sertoli cells in males** and **granulosa cells in females**

Question 1

Cephalic index is calculated as

Accepted Answer

Biparietal Diameter / Occipitofrontal Diameter

Answer

Biparietal Diameter / Head Circumference

Answer

Head Circumference / Femur Length

Answer

Occipitofrontal Diameter / Biparietal Diameter

Question 2

Number of stem villi at term in human placenta is?

Accepted Answer

240

Answer

60

Answer

120

Answer

480

Question 3

Which of the following is NOT typically associated with Kallmann's syndrome?

Accepted Answer

Excess stimulation of the HPO axis

Answer

Hypogonadotropic hypogonadism

Answer

Anosmia

Answer

Amenorrhea

Question 4

A pregnant woman at term presents with a symphysiofundal height of 40 cm. What is the most likely approximate fetal weight?

Accepted Answer

4 kg

Answer

3 kg

Answer

3.3 kg

Answer

4.3 kg

Question 5

What is the primary hormonal cause of hot flushes experienced during menopause?

Accepted Answer

Decreased estrogen levels

Answer

Increased noradrenaline with normal estrogen levels

Answer

Increased noradrenaline

Answer

Both increased noradrenaline and decreased estrogen levels

Question 6

What is the recommended dose of folic acid for a patient with a history of neural tube defect (NTD) in a previous pregnancy?

Accepted Answer

4 mg

Answer

0.5 mg

Answer

1 mg

Answer

2 mg

Question 7

A G2P1L1 female presents at 28 weeks of gestation with a 1:4 anti-D titre. What is the most appropriate management option?

Accepted Answer

MCA Doppler

Answer

Caesarean section

Answer

Induction of labour

Answer

Amniocentesis

Question 8

Which of the following is true regarding precocious puberty:

Accepted Answer

Sexual maturity is attained early

Answer

Mental function is increased

Answer

Reproductive function is absent

Answer

Body proportions remain unchanged

Question 9

The role of human placental lactogen is :

Accepted Answer

Supports fetal growth and development.

Answer

Stimulate milk production

Answer

Promotes growth of breast for lactation.

Answer

Provide fetal nutrition by antagonizing the action of insulin in maternal circulation, breakdown of fats and proteins and transport of fatty acids and amino acids from maternal to fetal circulation.

Question 10

Antimullerian hormone is secreted by ?

Accepted Answer

Both Sertoli cells and granulosa cells

Answer

Theca cells

Answer

Leydig cells

Answer

None of the above

NEET-PG 2015

Anatomy

Internal Medicine

Obstetrics and Gynecology

Pediatrics

Physiology