NEET-PG 2012 Practice Questions

Q: Which is derived from Wolffian duct?

Appendix of epididymis. The **appendix of the epididymis** is a vestigial structure directly derived from the mesonephric (Wolffian) duct in males. It is an embryological remnant of this duct, located at the head of the epididymis. *Appendix of the testis* - The **appendix of the testis** (hydatid of Morgagni) is a remnant of the paramesonephric (Müllerian) duct, not the Wolffian duct. - It is usually found on the upper pole of the testis, typically near the epididymis. *Uterine structure* - **Uterine structures** (uterus, fallopian tubes, and upper vagina) are derived from the paramesonephric (Müllerian) ducts in females [1]. - The Wolffian ducts largely regress in females due to the absence of testosterone. *Hydatid of Morgagni* - The term **hydatid of Morgagni** can refer to the appendix of the testis (Müllerian duct remnant) or, less commonly, to the appendix of the epididymis (Wolffian duct remnant). - However, in common clinical and anatomical usage, it almost exclusively refers to the **appendix of the testis**, which is a Müllerian duct derivative.

Q: Haploid number of chromosomes is first seen in?

Secondary spermatocyte. ***Secondary spermatocyte*** - A secondary spermatocyte is formed after **meiosis I**, where the homologous chromosomes are separated, resulting in a cell with a **haploid number of chromosomes (n)**, although each chromosome still consists of two sister chromatids. - This is the **first stage** where haploidy is achieved in spermatogenesis. - These cells are transient and quickly undergo meiosis II to form spermatids. *Spermatogonia* - Spermatogonia are **diploid (2n)** germline stem cells that undergo mitosis to produce more spermatogonia or differentiate into primary spermatocytes. - They contain the full complement of chromosomes found in somatic cells. *Primary spermatocytes* - Primary spermatocytes are also **diploid (2n)** cells that enter meiosis I. - Before meiosis I, DNA replication occurs, so each chromosome consists of two sister chromatids, but the cell still maintains a diploid chromosome number. *Spermatids* - Spermatids are formed after **meiosis II** from secondary spermatocytes and are also **haploid (n)**. - However, secondary spermatocytes become haploid **earlier** in the process, immediately following the reductional division of meiosis I.

Q: Right ovarian artery is a branch of ?

Abdominal aorta. ***Abdominal aorta*** - The **right ovarian artery** typically originates directly from the **abdominal aorta**, just inferior to the renal arteries [1]. - This is a direct branch, supplying blood to the **right ovary**, **fallopian tube**, and surrounding structures [1]. *Right internal iliac* - The **internal iliac artery** primarily supplies the **pelvic organs**, gluteal region, and medial thigh [1]. - While it has branches to pelvic structures, the ovarian artery does not originate from it. *Common iliac* - The **common iliac artery** bifurcates into the **internal and external iliac arteries** at the level of the sacroiliac joint. - It does not directly give off the ovarian artery. *External iliac* - The **external iliac artery** continues as the **femoral artery** below the inguinal ligament, primarily supplying the lower limb. - It does not give off branches to the ovary.

Q: The nutrient artery to the femur is?

Profunda femoris artery. ***Profunda femoris artery*** - The **profunda femoris artery** (deep femoral artery) is the main blood supply to the **femur's diaphysis** via its perforating branches. - Typically, the **second perforating branch** gives rise to the nutrient artery, which enters the bone through the **nutrient foramen** in the middle third of the femoral shaft. *Femoral artery* - The **femoral artery** is the main artery of the thigh and gives off several branches, including the profunda femoris artery. - While it is the source of blood for the entire lower limb, it does not directly give rise to the main **nutrient artery of the femur**. *Popliteal artery* - The **popliteal artery** is a continuation of the femoral artery in the popliteal fossa behind the knee. - It primarily supplies structures around the knee joint and the lower leg, not the direct **diaphyseal nutrient supply** to the femur. *Medial circumflex femoral artery* - The **medial circumflex femoral artery** primarily supplies the head and neck of the femur, crucial for its vascularity, especially in children. - It does not serve as the **main nutrient artery** for the femoral shaft (diaphysis).

Q: Most common cause of nephrotic syndrome in adults?

Focal Segmental Glomerulosclerosis (FSGS). ***Membranous glomerulonephritis*** - Membranous glomerulonephritis is the **most common cause of nephrotic syndrome** in adults, often associated with **autoimmune diseases** or certain medications. [1] - Patients typically present with **heavy proteinuria**, edema, and a normal renal function in early stages. *Focal GN* - Focal glomerulosclerosis typically affects young individuals and may not usually present as nephrotic syndrome. - It is associated with **obesity** and **HIV**, often leading to more significant renal impairment compared to membranous glomerulonephritis. [1] *Acute GN* - Acute glomerulonephritis generally presents with **hematuria**, **hypertension**, and **renal failure**, rather than nephrotic syndrome. [1] - It can have different causes, such as infections or systemic diseases, but is not the primary condition leading to nephrotic syndrome in adults. *Minimal change disease* - Minimal change disease is more prevalent in **children** [1], and while it can occur in adults, it is less common as a cause of nephrotic syndrome in this demographic. - It is characterized by **responsive edema** to steroids, but its incidence is not as high as membranous glomerulonephritis in adults.

Q: What is the term for a localized malformation composed of an excessive but disorganized arrangement of cells and tissues indigenous to the site?

Hamartoma. ***Hamartoma*** - A **hamartoma** is an overgrowth of cells and tissues that are normally found in the affected area, but in a disordered fashion, creating a tumor-like growth [1]. - It's a **benign (non-cancerous)** lesion, often congenital, that grows at the same rate as the surrounding tissues. *Malignant tumor* - A **malignant tumor** is characterized by uncontrolled cell growth that invades surrounding tissues and can metastasize to distant sites. - Unlike a hamartoma, a malignant tumor consists of **abnormal, dysplastic cells** that do not resemble the normal tissues of the organ. *Choristoma* - A choristoma is a **benign tumor-like growth** consisting of normal cells or tissues that are **heterotopic**, meaning they are located in an abnormal site. - An example is the presence of pancreatic tissue in the wall of the stomach, which is normal tissue in an abnormal location, unlike a hamartoma which has normal tissue in the correct location but in a disorganized manner. *None of the options* - This option is incorrect because **hamartoma** accurately describes the overgrowth of a skin structure at a localized region made of normal, but disorganized, tissue [1]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Disorders Involving Inflammatory And Haemopoietic Cells, pp. 651-652.

Q: All of the following provide protection against malaria except which of the following?

PNH. ***PNH*** - Paroxysmal Nocturnal Hemoglobinuria (PNH) does not provide any **protection against malaria**; it is an acquired bone marrow disorder. - While it leads to increased hemolysis and thrombosis, it does not affect **malaria susceptibility** directly. *Duffy blood group* - The Duffy blood group has specific antigens that are a **receptor for Plasmodium vivax**, making individuals with a Duffy-negative phenotype resistant to this type of malaria. - Therefore, Duffy blood group status can indeed serve as a protective factor against certain malaria strains. *Hereditary spherocytosis* - This condition results in **spherical red blood cells** [1], causing hemolytic anemia, but it does not confer protection against malaria. - People with hereditary spherocytosis do not have a lower prevalence of malaria and may still be susceptible to infection. *Sickle cell anemia* - Individuals with sickle cell anemia often exhibit **increased resistance to malaria**, especially against Plasmodium falciparum [2]. - The sickling of red blood cells under low oxygen conditions creates an unfavorable environment for the malarial parasites to thrive [2, 3].

Q: What is the venous hematocrit level at which you will diagnose polycythemia in a newborn?

65%. ***Correct: 65%*** - **Polycythemia** in a newborn is typically diagnosed when the **venous hematocrit** is **≥65%**. - This threshold indicates an abnormally high concentration of **red blood cells**, increasing blood viscosity. *Incorrect: 55%* - A venous hematocrit of 55% is generally considered within the **normal range** for a newborn, especially within the first few hours of life. - It does not meet the criteria for diagnosing **polycythemia**. *Incorrect: 60%* - While 60% is elevated compared to adult norms, it is still generally within the higher end of the **normal range** for an infant. - This level alone is usually **not sufficient** to diagnose **polycythemia** or warrant intervention without other clinical signs. *Incorrect: 70%* - A venous hematocrit of 70% definitely indicates **polycythemia** and significant **hyperviscosity**. - However, the diagnostic threshold for polycythemia is **65%**, meaning the condition is identified earlier.

Q: What happens to the concentration of inulin as fluid passes through the Proximal Convoluted Tubule (PCT)?

Concentration of inulin increases. ***Concentration of inulin increases*** - Inulin is **freely filtered** at the glomerulus and is neither reabsorbed nor secreted along the renal tubule, making it an excellent marker for **glomerular filtration rate (GFR)**. - As water is reabsorbed from the PCT, the volume of tubular fluid decreases, causing the concentration of **unreabsorbed solutes**, like inulin, to increase. *Concentration of urea remains constant* - Urea is **reabsorbed** along the tubule, though passively; its concentration typically **increases** initially in the PCT due to water reabsorption, but then decreases as some is reabsorbed. - The statement is incorrect because urea concentration changes significantly throughout the nephron, particularly increasing as water is reabsorbed and then decreasing with some reabsorption. *Concentration of HCO3- increases* - The majority (approximately 80-90%) of **bicarbonate (HCO3-)** is reabsorbed in the PCT, primarily through its conversion to CO2 within the tubular lumen and then back to HCO3- intracellularly. - Therefore, the concentration of HCO3- in the tubular fluid actually **decreases** significantly as fluid passes through the PCT. *Concentration of Na+ decreases* - **Sodium (Na+)** is actively reabsorbed along the entire nephron, with about 65-70% reabsorbed in the PCT. - While Na+ is reabsorbed, water follows passively, so its concentration in the tubular fluid remains relatively **iso-osmotic** with plasma, meaning its concentration does not significantly decrease as fluid passes through the PCT, remaining fairly constant.

Q: The primary site of vasopressin synthesis is

Supraoptic nucleus. ***Supraoptic nucleus*** - The **supraoptic nucleus** of the hypothalamus is the **primary site** for the synthesis of **vasopressin** (also known as antidiuretic hormone or ADH). - Approximately **80% of vasopressin** is produced by the neurosecretory cells in this nucleus. - The synthesized vasopressin is transported down axons to the posterior pituitary for storage and release. *Preoptic nucleus* - The **preoptic nucleus** is involved in various homeostatic functions, including **thermoregulation** and **sleep regulation**, but not the synthesis of vasopressin. - While it has neuronal connections to the hypothalamus, it does not produce ADH. *Paraventricular nucleus* - The **paraventricular nucleus** also synthesizes **both vasopressin and oxytocin**, accounting for approximately **20% of vasopressin production**. - While it does produce vasopressin, the **supraoptic nucleus remains the primary site**, making it the correct answer to this question. - The PVN also plays important roles in stress response and various autonomic functions. *Posterior pituitary* - The **posterior pituitary** (neurohypophysis) is responsible for the **storage and release** of vasopressin and oxytocin, not their synthesis. - These hormones are produced in the hypothalamic nuclei (supraoptic and paraventricular) and then transported down axonal tracts to the posterior pituitary.

Question 1

Which is derived from Wolffian duct?

Accepted Answer

Appendix of epididymis

Answer

Appendix of the testis

Answer

Uterine structure

Answer

Hydatid of Morgagni

Question 2

Haploid number of chromosomes is first seen in?

Accepted Answer

Secondary spermatocyte

Answer

Spermatogonia

Answer

Primary spermatocytes

Answer

Spermatids

Question 3

Right ovarian artery is a branch of ?

Accepted Answer

Abdominal aorta

Answer

Right internal iliac

Answer

Common iliac

Answer

External iliac

Question 4

The nutrient artery to the femur is?

Accepted Answer

Profunda femoris artery

Answer

Femoral artery

Answer

Popliteal artery

Answer

Medial circumflex femoral artery

Question 5

Most common cause of nephrotic syndrome in adults?

Accepted Answer

Focal Segmental Glomerulosclerosis (FSGS)

Answer

Minimal change disease

Answer

Acute GN

Answer

Membranous glomerulonephritis

Question 6

What is the term for a localized malformation composed of an excessive but disorganized arrangement of cells and tissues indigenous to the site?

Accepted Answer

Hamartoma

Answer

Malignant tumor

Answer

Choristoma

Answer

None of the options

Question 7

All of the following provide protection against malaria except which of the following?

Accepted Answer

PNH

Answer

Sickle cell anemia

Answer

Hereditary spherocytosis

Answer

Duffy blood group

Question 8

What is the venous hematocrit level at which you will diagnose polycythemia in a newborn?

Accepted Answer

65%

Answer

55%

Answer

60%

Answer

70%

Question 9

What happens to the concentration of inulin as fluid passes through the Proximal Convoluted Tubule (PCT)?

Accepted Answer

Concentration of inulin increases

Answer

Concentration of urea remains constant

Answer

Concentration of HCO3- increases

Answer

Concentration of Na+ decreases

Question 10

The primary site of vasopressin synthesis is

Accepted Answer

Supraoptic nucleus

Answer

Preoptic nucleus

Answer

Paraventricular nucleus

Answer

Posterior pituitary

NEET-PG 2012

Anatomy

Internal Medicine

Pathology

Pediatrics

Physiology