Biochemistry
1 questionsWhich of these is not a part of extracellular matrix:
NEET-PG 2015 - Biochemistry NEET-PG Practice Questions and MCQs
Question 1011: Which of these is not a part of extracellular matrix:
- A. Collagen
- B. Laminin
- C. Fibronectin
- D. Integrins (Correct Answer)
Explanation: ***Integrins*** - Integrins are **transmembrane receptors** on the cell surface that facilitate cell-extracellular matrix (ECM) adhesion and cell-cell adhesion. - They are part of the cell membrane, **not** an extracellular component. *Laminin* - **Laminin** is a major protein component of the **basal lamina**, a specialized extracellular matrix that underlies epithelial cells. - It plays a crucial role in cell adhesion, differentiation, and migration within the ECM. *Fibronectin* - **Fibronectin** is a large glycoprotein present in the **extracellular matrix** and in soluble form in blood plasma. - It mediates cell adhesion to the ECM by binding to integrins and various ECM components like collagen and proteoglycans. *Collagen* - **Collagen** is the most abundant protein in the human body and a primary structural component of the **extracellular matrix**. - It provides tensile strength and structural integrity to tissues like skin, bone, tendons, and cartilage.
Obstetrics and Gynecology
8 questionsAll are true about uteroplacental circulation except:
Which serum level is increased in premature ovarian failure?
Which of the following is not considered a marker of ovarian reserve?
Which of the following is a side effect of Progestin Only Pills (POPs)?
Which of the following is not associated with maternal age?
What should be done if 2 OCPs are missed on days 17-18 of the cycle?
Most common complication of dermoid cyst is -
What is a common cause of unilateral dysmenorrhea?
NEET-PG 2015 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 1011: All are true about uteroplacental circulation except:
- A. The villi depend on the maternal blood for their nutrition
- B. Blood in the intervillous space is completely replaced 3-4 times per minute
- C. A mature placenta has 150 ml of blood in the villi system and 350 ml of blood in the intervillous space (Correct Answer)
- D. Intervillous blood flow at term is 500-600 ml per minute
Explanation: ***A mature placenta has 150 ml of blood in the villi system and 350 ml of blood in the intervillous space*** - This statement is incorrect because a **mature placenta** typically holds approximately **350 ml of blood** in the **villi system** and **150 ml of blood** in the **intervillous space**, which is the reverse of what is stated. - The villi system contains the fetal blood, which has a larger volume within the placental unit. *Blood in the intervillous space is completely replaced 3-4 times per minute* - This is a correct statement regarding uteroplacental circulation, as the **high turnover rate** ensures efficient **nutrient and gas exchange** between mother and fetus. - The rapid replacement prevents stagnant blood and facilitates continuous delivery of essential substances. *The villi depend on the maternal blood for their nutrition* - This statement is true because the **chorionic villi**, which are the functional units of the placenta, are bathed in **maternal blood** within the intervillous space. - The placental tissue itself receives its **nutrients and oxygen** directly from this maternal blood supply. *Intervillous blood flow at term is 500-600 ml per minute* - This is an accurate physiological fact. At term, the **maternal blood flow** through the intervillous space is indeed substantial, typically ranging from **500 to 700 ml per minute**, ensuring adequate perfusion for the growing fetus. - This significant blood flow is crucial for meeting the high metabolic demands of the fetus.
Question 1012: Which serum level is increased in premature ovarian failure?
- A. Serum Inhibin
- B. Serum FSH (Correct Answer)
- C. Serum Estradiol
- D. Serum Progesterone
Explanation: ***Serum FSH*** - In **premature ovarian failure**, the ovaries fail to produce sufficient estrogen and inhibin, leading to a loss of negative feedback on the pituitary gland. - This lack of negative feedback results in continuously **elevated levels of FSH** as the pituitary tries to stimulate the non-responsive ovaries. *Serum Inhibin* - **Inhibin** is a hormone produced by ovarian granulosa cells, which normally inhibits FSH secretion. - In premature ovarian failure, due to ovarian dysfunction, **inhibin levels are typically decreased**, not increased. *Serum Estradiol* - **Estradiol** is the primary estrogen produced by the ovaries. - In premature ovarian failure, the ovaries are failing, resulting in **decreased production of estrogen/estradiol**. *Serum Progesterone* - **Progesterone** is primarily produced after ovulation by the corpus luteum. - In premature ovarian failure, ovulation is impaired or absent, leading to **low or undetectable progesterone levels**.
Question 1013: Which of the following is not considered a marker of ovarian reserve?
- A. Ovarian volume
- B. Inhibin B
- C. Anti-Müllerian Hormone (AMH)
- D. Inhibin A (Correct Answer)
Explanation: ***Inhibin A*** - **Inhibin A** levels primarily rise during the mid to late luteal phase and are involved in regulating FSH, but they are not a reliable or commonly used marker for **ovarian reserve**. - Its fluctuations are more indicative of the presence of a **corpus luteum** and short-term ovarian function rather than the total follicular pool. *Inhibin B* - **Inhibin B** is produced by granulosa cells of small antral follicles and is an important marker of **ovarian reserve**. - It inversely correlates with **FSH** levels in the early follicular phase, reflecting the number of developing follicles. *Ovarian volume* - **Ovarian volume**, particularly when measured by ultrasound, can be an indicator of **ovarian reserve**. - Smaller ovarian volume is generally associated with a reduced number of **antral follicles** and lower ovarian reserve. *Anti-Müllerian Hormone (AMH)* - **AMH** is a well-established and highly reliable marker of **ovarian reserve**, produced by the granulosa cells of preantral and small antral follicles. - Its levels correlate directly with the total number of remaining **primordial follicles** and are relatively stable throughout the menstrual cycle.
Question 1014: Which of the following is a side effect of Progestin Only Pills (POPs)?
- A. Ovarian cysts (Correct Answer)
- B. Venous thromboembolism
- C. Increased risk of diabetes mellitus
- D. Ectopic pregnancy
Explanation: ***Ovarian cysts*** - **Functional ovarian cysts** are a known side effect of Progestin Only Pills (**POPs**), as POPs can alter the normal ovulatory cycle but usually do not completely suppress follicular development. - While generally benign and self-resolving, they can cause pain and discomfort. *Venous thromboembolism* - **POPs** are not significantly associated with an increased risk of **venous thromboembolism** due to the absence of estrogen, unlike combined hormonal contraceptives. - This is a key advantage of POPs, making them suitable for individuals at risk for thromboembolic events. *Increased risk of diabetes mellitus* - There is generally **no significant increased risk** of **diabetes mellitus** associated with POPs. - While some hormonal contraceptives *may* have minor effects on glucose metabolism, this is not a prominent or clinically significant side effect of POPs. *Ectopic pregnancy* - POPs **do not increase the risk of ectopic pregnancy**. In fact, they **reduce the overall pregnancy rate**, including ectopic pregnancies, by preventing ovulation. - However, if a pregnancy does occur while on POPs, there is a *slightly higher proportion* of those pregnancies that may be ectopic compared to unaided conceptions, but the *absolute risk* remains low.
Question 1015: Which of the following is not associated with maternal age?
- A. Preterm labour
- B. Aneuploidy
- C. Hydatidiform mole
- D. Post maturity (Correct Answer)
Explanation: ***Post maturity*** - **Post-maturity** (post-term pregnancy, >42 weeks) does NOT have a consistent or strong association with maternal age in current obstetric literature. - While some older studies suggested associations, modern evidence shows **no significant independent effect of maternal age** on post-term pregnancy rates. - Post-term pregnancy is more related to factors like **first pregnancy**, **prior post-term delivery**, and **fetal sex** (males more common). *Preterm labour* - **Preterm birth is strongly associated with maternal age**, particularly at both extremes: - **Teenage mothers** (<20 years): Increased risk due to biological immaturity and socioeconomic factors - **Advanced maternal age** (≥35 years): Increased risk due to higher rates of maternal complications (hypertension, diabetes) and placental dysfunction - This is well-established in obstetric literature and clinical guidelines. *Aneuploidy* - The risk of **aneuploidy**, particularly **Down syndrome (Trisomy 21)**, **increases dramatically with advancing maternal age**. - At age 35: ~1/350 risk; at age 40: ~1/100 risk; at age 45: ~1/30 risk - Due to age-related decline in oocyte quality causing meiotic errors during egg formation. *Hydatidiform mole* - **Gestational trophoblastic disease** (hydatidiform mole) is strongly associated with **extremes of maternal age**: - **Women >40 years**: 5-10 fold increased risk - **Teenagers**: 1.5-2 fold increased risk - Related to abnormal fertilization events more common at age extremes.
Question 1016: What should be done if 2 OCPs are missed on days 17-18 of the cycle?
- A. Take 2 pills on the next 2 days
- B. Continue taking single pill per day
- C. Use back up contraceptive
- D. Both a and b (Correct Answer)
Explanation: ***Both a and b*** - When **two OCPs are missed** on days 17-18 (Week 3) of the cycle, the recommended approach combines two actions to restore contraceptive protection. - The woman should **take two pills on the next two days** to compensate for the missed doses and restore hormonal levels quickly. - Additionally, **backup contraception should be used for at least 7 days** to ensure contraceptive effectiveness, as the missed pills during Week 3 could compromise protection and increase the risk of ovulation. - Both actions together address the hormonal gap and provide adequate contraceptive coverage. *Take 2 pills on the next 2 days* - While this action helps **reestablish hormone levels** after missing two pills, it is **insufficient on its own**. - Without concurrent backup contraception, there remains a risk of **ovulation** and **unintended pregnancy** during the recovery period. - This must be combined with backup contraceptive methods for 7 days. *Use back up contraceptive* - Using **backup contraception** is essential because missing two pills in Week 3 increases the risk of **ovulation**. - However, backup contraception alone without resuming the pill regimen (with catch-up dosing) would not adequately restore the hormonal cycle. - Both resuming pills appropriately and using backup methods are necessary. *Continue taking single pill per day* - Simply continuing with one pill per day without any catch-up dosing would leave a **hormonal gap** from the two missed pills. - This approach does not compensate for the **missed active hormones**, leaving inadequate hormone levels for contraceptive protection. - Without catch-up dosing and backup contraception, the risk of **ovulation** and **pregnancy** remains significantly elevated.
Question 1017: Most common complication of dermoid cyst is -
- A. Cyst Rupture
- B. Torsion (Correct Answer)
- C. Malignant degeneration
- D. Infection
Explanation: ***Torsion*** - Ovarian dermoid cysts (mature cystic teratomas) are prone to **torsion** due to their common unilateral, round, and easily mobile nature. - Torsion results from the **twisting of the ovarian pedicle**, which can lead to exquisite pain and potential **ischemic necrosis** of the ovary. - **Most common complication** occurring in **15-20% of dermoid cysts**. *Cyst Rupture* - While rupture can occur, it is a **less common complication** than torsion, occurring in **1-4% of cases**. - Rupture can release sebaceous material and hair into the peritoneal cavity, leading to **chemical peritonitis**. *Malignant degeneration* - **Malignant transformation** within a dermoid cyst is rare, occurring in **less than 1-2% of cases**, making it much less common than torsion. - The most common type of malignancy arising from a dermoid cyst is **squamous cell carcinoma**. *Infection* - **Secondary infection** of dermoid cysts is a rare complication. - Much less common than torsion, and typically presents with fever, pain, and signs of inflammation.
Question 1018: What is a common cause of unilateral dysmenorrhea?
- A. One horn of malformed uterus (Correct Answer)
- B. Small fibroid at the utero tubal junction
- C. Endometriosis causing unilateral pain
- D. All of the options
Explanation: ***One horn of malformed uterus*** - **Obstructed rudimentary horn** with functional endometrium or **obstructed hemivagina** in uterine anomalies is a **classic cause of unilateral dysmenorrhea**. - The obstruction leads to accumulation of menstrual blood in the non-communicating horn or hemivagina, causing **severe cyclical unilateral pelvic pain** that worsens progressively with each menstrual cycle. - This typically presents in **adolescents or young women** after menarche and is a well-recognized gynecological emergency requiring surgical intervention. - Examples include: **unicornuate uterus with non-communicating rudimentary horn**, **uterus didelphys with obstructed hemivagina** (OHVIRA syndrome). *Endometriosis causing unilateral pain* - While endometriosis causes **dysmenorrhea**, it typically presents with **bilateral pelvic pain** and diffuse tenderness. - Endometriosis pain is usually **generalized** rather than strictly unilateral, though asymmetric involvement can occur. - The pain is associated with **deep dyspareunia**, **dyschezia**, and chronic pelvic pain rather than strictly unilateral cyclical pain. *Small fibroid at the utero tubal junction* - Fibroids (leiomyomas) can cause **dysmenorrhea and menorrhagia**, but unilateral presentation is uncommon. - Cornual fibroids may cause localized pain, but this is not a typical or common presentation of **unilateral dysmenorrhea**. - Pain from fibroids is usually related to **degeneration** or pressure effects rather than cyclical unilateral menstrual pain. *All of the options* - While multiple conditions can cause pelvic pain, **obstructed müllerian anomalies** (one horn of malformed uterus) are the **most classic and important cause** of true unilateral dysmenorrhea. - This is the diagnosis that must be ruled out when a patient presents with unilateral cyclical pelvic pain.
Surgery
1 questionsWhich of the following neck dissections is considered the most conservative?
NEET-PG 2015 - Surgery NEET-PG Practice Questions and MCQs
Question 1011: Which of the following neck dissections is considered the most conservative?
- A. Supraomohyoid neck dissection (Correct Answer)
- B. Radical neck dissection
- C. Modified radical neck dissection
- D. All options are conservative.
Explanation: ***Supraomohyoid neck dissection*** - This dissection is highly **selective**, removing only lymph nodes from **levels I, II, and III**, which are the most superficial and anterior groups in the neck. - It preserves the **internal jugular vein**, spinal accessory nerve, and sternocleidomastoid muscle, minimizing functional and cosmetic morbidity. *Radical neck dissection* - This is the **most extensive** neck dissection, involving the removal of all lymph node levels (I-V), the **internal jugular vein**, the **spinal accessory nerve**, and the **sternocleidomastoid muscle**. - It is reserved for advanced cancers with extensive nodal involvement due to its significant associated morbidity and functional deficits. *Modified radical neck dissection* - This dissection removes lymph nodes in levels I-V but **spares at least one non-lymphatic structure**, such as the spinal accessory nerve, internal jugular vein, or sternocleidomastoid muscle. - While less radical than a full radical neck dissection, it is still more extensive than a supraomohyoid dissection as it targets a broader range of lymph node levels. *All options are conservative.* - This statement is incorrect because **radical neck dissection** is by definition the most extensive and least conservative surgical approach to neck nodal disease. - The different types of neck dissections represent a spectrum of extensiveness, with supraomohyoid being the most selective and conservative.