Anatomy
5 questionsBronchogenic sequestration is seen in which lobe?
Which is derived from Wolffian duct?
Which muscle stabilizes the clavicle during movement of the shoulder?
All are derived from ectoderm except for which of the following?
What anatomical structures are involved in the closure of the fossa ovalis?
NEET-PG 2012 - Anatomy NEET-PG Practice Questions and MCQs
Question 211: Bronchogenic sequestration is seen in which lobe?
- A. Left lower lobe (Correct Answer)
- B. Right upper lobe
- C. Left upper lobe
- D. Right middle lobe
Explanation: ***Left lower lobe*** - **Bronchopulmonary sequestration**, particularly the **intralobar type**, most commonly affects the **posterior basal segment of the left lower lobe**. [1] - This congenital malformation involves a segment of lung tissue that lacks normal communication with the tracheobronchial tree and receives its blood supply from a systemic artery. [1] *Right upper lobe* - While sequestration can occur anywhere, the **right upper lobe** is a much less common location for bronchopulmonary sequestration compared to the lower lobes. - Sequestration in the upper lobes is rare and usually associated with specific anatomical variations. *Right middle lobe* - The **right middle lobe** is also an infrequent site for bronchopulmonary sequestration. - The typical presentation involves the basal segments of the lower lobes due to embryonic developmental patterns. *Left upper lobe* - **Left upper lobe** involvement in bronchopulmonary sequestration is uncommon. - The majority of cases are found in the lower lobes, especially the left lower lobe.
Question 212: Which is derived from Wolffian duct?
- A. Appendix of epididymis (Correct Answer)
- B. Appendix of the testis
- C. Uterine structure
- D. Hydatid of Morgagni
Explanation: 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.
Question 213: Which muscle stabilizes the clavicle during movement of the shoulder?
- A. Pectoralis major
- B. Latissimus dorsi
- C. Subclavius (Correct Answer)
- D. Serratus anterior
Explanation: ***Subclavius*** - The **subclavius muscle** originates from the first rib and inserts into the inferior surface of the clavicle, acting to **depress the clavicle** and prevent its displacement, thus enhancing shoulder stability during movement. - It plays a crucial role in protecting the underlying **neurovascular structures** (brachial plexus and subclavian vessels) from external trauma to the shoulder. *Pectoralis major* - This large, fan-shaped muscle primarily functions in **adduction, medial rotation, and flexion of the humerus** at the shoulder joint [1]. - It does not directly stabilize the clavicle but rather acts on the arm. *Latissimus dorsi* - The **latissimus dorsi** is a broad muscle of the back responsible for **extension, adduction, and internal rotation of the humerus** [1]. - Its actions are mainly on the humerus and it does not directly stabilize the clavicle. *Serratus anterior* - The **serratus anterior** muscle primarily **protracts and rotates the scapula**, keeping it pressed against the thoracic wall. - While it's essential for **scapular stability** and overhead arm movements, it does not directly stabilize the clavicle.
Question 214: All are derived from ectoderm except for which of the following?
- A. Hair follicles
- B. Nails
- C. Lens of the eye
- D. Adrenal cortex (Correct Answer)
Explanation: ***Adrenal cortex*** - The adrenal cortex is derived from the **intermediate mesoderm**, specifically from the cells lining the posterior abdominal wall. The cells migrate to develop into the adrenal cortex. - It produces various steroid hormones, including **aldosterone**, **cortisol**, and **androgens**, which regulate diverse bodily functions. *Lens of the eye* - The lens of the eye is derived from the **surface ectoderm**. It forms from an invagination of the surface ectoderm called the lens placode. - Its primary function is to **focus light** onto the retina. *Hair follicles* - Hair follicles develop from the **surface ectoderm** [1]; they are invaginations of the epidermis that extend into the dermis. - They produce hair, which provides **insulation** and **protection** [1]. *Nails* - Nails are also derivatives of the **surface ectoderm**, forming thickened plates on the dorsal surface of the distal phalanges. - They provide **protection** to the fingertips and aid in grasping objects.
Question 215: What anatomical structures are involved in the closure of the fossa ovalis?
- A. Septum primum + Endocardial cushion
- B. Septum primum + Septum secundum (Correct Answer)
- C. Endocardial cushions + Septum secundum
- D. None of the options
Explanation: The septum primum acts as a valve, closing against the septum secundum postnatally due to changes in atrial pressure. This fusion effectively closes the foramen ovale, leading to the formation of the fossa ovalis. The endocardial cushions are important for the formation of the atrial and ventricular septa, as well as the AV valves, but not directly for the closure of the fossa ovalis. The septum primum is directly involved, but its apposition with the endocardial cushions doesn't close the foramen ovale. While both structures contribute to heart development, their direct interaction is not responsible for the closure of the fossa ovalis. The septum secundum forms the muscular rim of the fossa ovalis, and the endocardial cushions are critical for atrial septation, but not the final closure here. This option is incorrect because the specific combination of septum primum and septum secundum is indeed responsible for the closure of the fossa ovalis.
Biochemistry
2 questionsMale to male transmission is seen in -
Glycogen synthase is activated by?
NEET-PG 2012 - Biochemistry NEET-PG Practice Questions and MCQs
Question 211: Male to male transmission is seen in -
- A. Autosomal dominant diseases (Correct Answer)
- B. Autosomal recessive
- C. X-linked dominant
- D. Mitochondrial disease
Explanation: ***Autosomal dominant diseases*** - **Autosomal dominant** inheritance patterns involve a gene located on one of the **autosomes**, meaning it is not sex-linked. - Therefore, a father carrying an autosomal dominant gene can pass it to both sons and daughters with a **50% probability** for each child. - **Male-to-male transmission** is a hallmark feature that helps distinguish autosomal dominant from X-linked inheritance patterns. *Autosomal recessive* - **Autosomal recessive** diseases require **two copies** of the mutated gene (one from each parent) for the disease to manifest. - While a father can pass a recessive allele to his son, male-to-male transmission of the **disease phenotype** requires the mother to also be at least a carrier, making it not a defining feature of this inheritance pattern. - The key characteristic is horizontal pattern (affected siblings) rather than vertical transmission. *X-linked dominant* - In **X-linked dominant** inheritance, affected fathers **cannot** transmit the trait to their sons because sons inherit their **X chromosome** from their mother and their Y chromosome from their father. - All daughters of an affected father will inherit the affected X chromosome and thus the disease. - **Absence of male-to-male transmission** is a key distinguishing feature. *Mitochondrial disease* - **Mitochondrial diseases** are inherited exclusively from the **mother** to all her children, regardless of their sex. - Fathers with mitochondrial disease cannot transmit the condition to any of their children. - This shows **maternal inheritance only**, with no paternal transmission possible.
Question 212: Glycogen synthase is activated by?
- A. Insulin (Correct Answer)
- B. Glucagon
- C. AMP
- D. Epinephrine
Explanation: **Insulin** - Insulin activates **glycogen synthase** through a signaling cascade that dephosphorylates the enzyme, shifting it to its active form (glycogen synthase a). - This activation promotes **glycogen synthesis** in the liver and muscles, lowering blood glucose levels. *Glucagon* - **Glucagon** primarily acts to increase blood glucose levels by activating **glycogen phosphorylase** and inhibiting glycogen synthase. - It promotes the breakdown of glycogen (glycogenolysis) rather than its synthesis. *Epinephrine* - **Epinephrine** (adrenaline) also promotes **glycogenolysis** (glycogen breakdown) by activating glycogen phosphorylase. - Its main role is to provide rapid energy during stress, not to store glucose as glycogen. *AMP* - **AMP** (adenosine monophosphate) is a key allosteric activator of **AMP-activated protein kinase (AMPK)**, which phosphorylates and inactivates glycogen synthase. - High AMP levels signal a low energy state, prompting ATP-generating pathways like glycogenolysis, not glycogen synthesis.
Internal Medicine
1 questionsWhich of the following is not typically associated with cystic fibrosis?
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 211: Which of the following is not typically associated with cystic fibrosis?
- A. Infertility
- B. Azoospermia
- C. Nasal polyps
- D. Renal failure (Correct Answer)
Explanation: ***Renal failure*** - **Renal failure** is not a typical manifestation or complication of **cystic fibrosis (CF)**. The CFTR protein primarily affects epithelial cells in organs like the lungs, pancreas, liver, and intestines, not the kidneys. - While CF patients may experience **electrolyte imbalances** due to excessive salt loss, this rarely progresses to **kidney failure** as a direct result of the disease itself. *Infertility* - **Infertility** is commonly associated with CF, particularly in males due to **congenital bilateral absence of the vas deferens (CBAVD)**, which is found in over 95% of male CF patients [1]. - In females, CF can cause **viscous cervical mucus** and nutritional deficiencies, leading to challenges with conception [1]. *Azoospermia* - **Azoospermia**, specifically **obstructive azoospermia**, is a direct consequence of **congenital bilateral absence of the vas deferens (CBAVD)**, which is highly prevalent in male CF patients [1]. - This condition prevents sperm from reaching the ejaculate, despite normal sperm production in the testes. *Nasal polyps* - **Nasal polyps** are a common feature in patients with **cystic fibrosis**, often leading to **chronic rhinosinusitis** and nasal obstruction. - This is due to the dysfunctional CFTR protein leading to abnormal mucus production and inflammation in the nasal passages [1].
Pathology
2 questionsWhich of the following does not belong to the family of selectins?
What type of anaemia is primarily associated with leukaemia?
NEET-PG 2012 - Pathology NEET-PG Practice Questions and MCQs
Question 211: Which of the following does not belong to the family of selectins?
- A. P selectin
- B. L selectin
- C. A selectin (Correct Answer)
- D. E selectin
Explanation: ***A selectin*** - ***A selectin*** is not a recognized member of the selectin family, which includes other specific types. - The known selectins are **E-selectin**, **L-selectin**, and **P-selectin**, demonstrating a distinct classification [1]. *E selectin* - E selectin is a specific type of selectin expressed on **endothelial cells** activated by cytokines [1]. - It plays a crucial role in **leukocyte adhesion** during inflammation, distinguishing it as part of the selectin family [1]. *L selectin* - L selectin is involved in the **homing** of leukocytes to lymph nodes and forms part of the selectin family [1]. - Responsible for the initial tethering and rolling of leukocytes on **venular endothelium** [1]. *P selectin* - P selectin is found on platelets and endothelial cells and is critical in the **aggregation** of platelets and leukocytes. - It is also an established member of the selectin family, involved in **inflammatory responses** [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, p. 87.
Question 212: What type of anaemia is primarily associated with leukaemia?
- A. Aplastic anaemia
- B. Iron deficiency anaemia
- C. Megaloblastic anaemia
- D. Myelophthisic anaemia (Correct Answer)
Explanation: ***Myelophthisic anaemia*** - This condition arises from the **displacement of normal hematopoietic tissue** in the bone marrow by abnormal cells, like those seen in leukaemia, leading to **extramedullary hematopoiesis**. - Marrow infiltration causes **pancytopenia** and often results in the presence of **immature granulocytes** and **nucleated red blood cells** in the peripheral blood (leukoerythroblastosis). *Iron deficiency anaemia* - This type of anaemia is caused by insufficient iron for **hemoglobin synthesis**, often due to chronic blood loss or inadequate dietary intake. - While leukaemia patients can develop iron deficiency due to bleeding, it is not the **primary type of anaemia** directly resulting from the marrow infiltration by leukaemic cells. *Megaloblastic anaemia* - Characterized by the production of abnormally large, immature red blood cells, primarily due to **vitamin B12** or **folate deficiency**. - There is no direct causal link between leukaemia and the development of megaloblastic anaemia as a **primary haemato-pathological mechanism**. *Aplastic anaemia* - Characterized by **pancytopenia** due to bone marrow failure with hypocellular marrow, not marrow infiltration. - While both leukaemia and aplastic anaemia can present with cytopenias, aplastic anaemia shows a **hypocellular marrow** whereas leukaemia shows a **hypercellular marrow** with infiltration by malignant cells.