NEET-PG 2013 Practice Questions

Q: Pubic symphysis is which type of joint?

Secondary cartilaginous. ***Secondary cartilaginous*** - The **pubic symphysis** is a classic example of a **secondary cartilaginous joint**, also known as a **symphysis**. - These joints are characterized by a plate of **fibrocartilage** sandwiched between two layers of hyaline cartilage, uniting two bones and allowing for limited movement. *Gomphosis* - A **gomphosis** is a type of **fibrous joint** where a peg-like process fits into a socket, primarily found in the attachment of teeth to their sockets in the jaw. - It is distinct from the cartilaginous structure of the pubic symphysis. *Fibrous joint* - While fibrous joints are characterized by fibrous connective tissue connecting bones, this category is too broad, and doesn't specify the unique cartilaginous nature of the pubic symphysis. - Examples include sutures in the skull, syndesmoses, and gomphoses, none of which fit the structure of the pubic symphysis. *Primary cartilaginous* - A **primary cartilaginous joint**, or **synchondrosis**, involves bones united by **hyaline cartilage**, like the epiphyseal plates of growing bones. - These joints are typically temporary and eventually ossify, or they allow for very restricted movement, unlike the fibrocartilage and slight movement of the pubic symphysis.

Q: Sinus venosus receives blood from all EXCEPT:

Subcardinal vein. Sinus venosus receives blood from all EXCEPT: ***Subcardinal vein*** - The **subcardinal vein** is primarily involved in draining the developing **kidneys** and gonads during embryonic development. - While it contributes to the formation of the **inferior vena cava**, it does not directly empty into the sinus venosus. - The subcardinal veins are part of a different venous drainage system that develops independently from the sinus venosus tributaries. *Vitelline vein* - The **vitelline veins** drain blood from the **yolk sac**, which is the primary site of early hematopoiesis. - These veins directly empty into the **sinus venosus** in the early embryo. - They eventually give rise to the **hepatic portal system** and hepatic sinusoids. *Umbilical vein* - The **umbilical vein** carries **oxygenated and nutrient-rich blood** from the placenta to the fetus [1]. - In the early embryo, the umbilical veins drain directly into the **sinus venosus**. - Later in development, the left umbilical vein bypasses the liver via the **ductus venosus** to enter the inferior vena cava [1], [2]. *Common cardinal vein* - The **common cardinal veins** collect blood from the entire embryo, draining both the anterior (from the cephalic region) and posterior (from the trunk and lower limbs) parts. - These veins represent the main drainage system of the developing embryo and directly empty into the sinus venosus. - They are the primary tributaries of the sinus venosus during early cardiac development.

Q: Mastoid process is which type of epiphysis?

Traction epiphysis. Traction epiphysis - A traction epiphysis is an apophysis that does not contribute to the longitudinal growth of the bone but is located at the site of muscle attachment, serving to provide leverage for the muscle. - The mastoid process serves as an attachment point for various muscles, including the sternocleidomastoid, splenius capitis, and longissimus capitis, making it a classic example of a traction epiphysis. Pressure epiphysis - A pressure epiphysis is primarily responsible for the longitudinal growth of bone and is found at the ends of long bones, such as the femoral head or humeral head [1]. - The mastoid process does not contribute to longitudinal bone growth. Atavistic epiphysis - Atavistic epiphyses are those that are phylogenetically separate bones but become fused with the main bone during development, like the coracoid process of the scapula. - The mastoid process is an integral part of the temporal bone and is not considered a separate, phylogenetically distinct bone. Aberrant epiphysis - Aberrant epiphyses are variations that appear irregularly, are not always present, and do not have a consistent physiological role. - The mastoid process is a constant anatomical feature of the temporal bone in humans.

Q: How many ossification centers develop at the distal end of the humerus?

3. ***3*** - The distal end of the humerus develops **three primary ossification centers**: the capitellum, trochlea, and medial epicondyle [1]. - These centers appear sequentially and their ossification pattern is important for assessing **skeletal maturity** in children using the CRITOE mnemonic [1]. - The capitellum appears at 1 year, medial epicondyle at 5 years, and trochlea at 9 years. *2* - This number is too low and only accounts for the **capitellum and medial epicondyle**, missing the trochlea. - While these are the first two to appear, there is an additional primary ossification center (trochlea) that develops later. *5* - This number is incorrect; there are only **three primary ossification centers** at the distal humerus, not five. - This may cause confusion with other joints or by counting secondary ossification centers. *4* - This number is incorrect; while the lateral epicondyle does ossify, it is not consistently counted as a **primary ossification center**. - The standard anatomical teaching recognizes **three primary centers**: capitellum, trochlea, and medial epicondyle.

Q: Which of the following is NOT required for gluconeogenesis from lactate?

Transamination of pyruvate to alanine. ***Transamination of pyruvate to alanine*** - While **alanine** can be a substrate for gluconeogenesis, **lactate** is directly converted to pyruvate, which then enters the gluconeogenesis pathway. **Transamination to alanine** is not a required intermediate step for lactate-derived glucose production. - The direct conversion of **lactate to pyruvate** by **lactate dehydrogenase** is the key initial step, not its conversion to alanine. *Transport of lactate from muscle to liver* - **Lactate** produced in muscles (e.g., during intense exercise) must be transported to the **liver** via the bloodstream to be used for **gluconeogenesis** in the **Cori cycle**. - This transport is essential for clearing lactate from the periphery and supplying the liver with a gluconeogenic precursor. *Conversion of lactate to pyruvate* - **Lactate dehydrogenase** catalyzes the reversible conversion of **lactate to pyruvate**, which is the critical first step in converting lactate into a gluconeogenic substrate. - This reaction regenerates **NAD+** (not NADH), which is necessary for glycolysis to continue in muscle tissue. *None of the above* - This option is incorrect because there IS a step listed above that is not required: **transamination of pyruvate to alanine** is indeed not necessary for gluconeogenesis from lactate, making Option A the correct answer to this "NOT required" question.

Q: Which of the following is not an androgen?

17α-hydroxyprogesterone. ***17α-hydroxyprogesterone*** - This is a **progesterone derivative** and an intermediate in the synthesis of androgens and corticosteroids, but it does **not possess significant androgenic activity** itself. - Its primary role is as a precursor, rather than a direct androgen. *Testosterone* - **Testosterone** is the **primary male sex hormone** and a potent androgen, responsible for the development of male secondary sexual characteristics. - It plays crucial roles in muscle mass, bone density, libido, and erythropoiesis. *Dihydrotestosterone* - **Dihydrotestosterone (DHT)** is a potent androgen, formed from testosterone by the enzyme 5α-reductase. - DHT is responsible for the development of external male genitalia during fetal development and contributes to prostate growth and male pattern baldness in adults. *Androstenedione* - **Androstenedione** is a **weak androgen** and an important **precursor hormone** in the biosynthesis of testosterone and estrogens. - It is produced in the adrenal glands and gonads, serving as an intermediate step in steroidogenesis.

Q: What is the first permanent tooth to erupt?

First molar. ***First molar*** - The **first molars** are typically the first permanent teeth to erupt, usually around **6 years of age**. - They erupt distal to the primary second molars and are not preceded by primary teeth, making them crucial for establishing the **occlusion**. *First premolar* - **First premolars** typically erupt later, between **10 and 11 years of age**, replacing the primary first molars. - Their eruption is part of the **exchange of primary teeth** for permanent successors. *Second premolar* - The **second premolars** erupt even later, usually between **11 and 12 years of age**, replacing the primary second molars. - They are also involved in the **replacement of primary teeth**, not the initial permanent eruption. *Second molar* - **Second molars** erupt much later than the first molars, typically between **11 and 13 years of age**, distal to the first molars. - They are part of the **later stages of permanent dentition development**.

Q: What is the complete classic triad of findings that defines Young's syndrome?

Azoospermia, bronchiectasis, and chronic sinusitis. ***Azoospermia, bronchiectasis, and chronic sinusitis*** - Young's syndrome is characterized by the triad of **azoospermia** (due to obstructive epididymal dysfunction), **bronchiectasis**, and **chronic sinusitis** [1]. - This syndrome primarily affects **middle-aged men** and is often mistaken for cystic fibrosis due to similar respiratory symptoms. *Azoospermia, asthma, and chronic rhinitis* - This option incorrectly lists **asthma** and **chronic rhinitis** instead of bronchiectasis and chronic sinusitis. - While respiratory symptoms are part of Young's syndrome, specifically **bronchiectasis** and **sinusitis** are key [1]. *Oligospermia, bronchiectasis, and chronic sinusitis* - This option is incorrect because Young's syndrome is defined by **azoospermia** (complete absence of sperm), not just **oligospermia** (low sperm count). - The obstructive nature of the epididymal dysfunction in Young's syndrome leads to a complete lack of sperm. *Azoospermia, chronic bronchitis, and nasal polyps* - This option incorrectly identifies **chronic bronchitis** and **nasal polyps** as part of the classic triad. - The correct respiratory components are **bronchiectasis** and **chronic sinusitis**, which signify persistent inflammation and structural lung changes rather than simply bronchitis.

Q: Which is not a feature of paroxysmal nocturnal hemoglobinuria?

Increased LAP score. ***Increased LAP score*** - In paroxysmal nocturnal hemoglobinuria, the **LAP score** is typically **low** due to ineffective hematopoiesis and not elevated. - The presence of a low LAP score is inconsistent with the features of this condition, making it the correct choice. *Thrombosis* - Paroxysmal nocturnal hemoglobinuria is **associated with a high risk of thrombosis**, particularly in the **venous system** [2]. - This is due to **increased platelet activation** and excessive thrombin generation resulting from hemolysis. *Hemolysis* - **Hemolysis** is a hallmark feature of paroxysmal nocturnal hemoglobinuria, where there is **destruction of red blood cells** [2,3]. - Patients often present with signs of hemolytic anemia including **elevated bilirubin** and **low haptoglobin** levels. *Thrombocytopenia* - **Thrombocytopenia** is a common finding in paroxysmal nocturnal hemoglobinuria due to **expanded consumption** of platelets during episodes of hemolysis. - This can lead to an **increased risk of bleeding** in affected patients. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 601-602. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 650-651.

Q: What is the name of the syndrome associated with the deletion of chromosome 22?

Di George syndrome. ***Di George syndrome*** - Di George syndrome, also known as **22q11.2 deletion syndrome**, is caused by a deletion on the long arm of chromosome 22. - This syndrome is associated with varied clinical features, including **congenital heart defects**, **thymic hypoplasia** (leading to immune deficiencies), **hypocalcemia** due to parathyroid hypoplasia, and characteristic facial features. *Down syndrome* - Down syndrome is caused by a **trisomy of chromosome 21**, meaning there's an extra copy of chromosome 21. - It is characterized by intellectual disability, distinctive facial features, and developmental delays, and is not associated with chromosome 22 deletion. *Turner syndrome* - Turner syndrome is a chromosomal condition affecting females, characterized by the partial or complete absence of one of the **X chromosomes (45, X0)**. - It leads to short stature, ovarian dysfunction, and characteristic physical features, unrelated to chromosome 22. *Klinefelter syndrome* - Klinefelter syndrome is a chromosomal disorder in males resulting from an extra **X chromosome (47, XXY)**. - Individuals often experience hypogonadism, reduced fertility, and abnormal body proportions, which is distinct from a deletion on chromosome 22. *Prader-Willi syndrome* - Prader-Willi syndrome is caused by a **deletion of paternal chromosome 15q11-q13** or maternal uniparental disomy. - It presents with hypotonia, hyperphagia, obesity, intellectual disability, and hypogonadism, unrelated to chromosome 22 deletion.

Question 1

Pubic symphysis is which type of joint?

Accepted Answer

Secondary cartilaginous

Answer

Gomphosis

Answer

Fibrous joint

Answer

Primary cartilaginous

Question 2

Sinus venosus receives blood from all EXCEPT:

Accepted Answer

Subcardinal vein

Answer

Vitelline vein

Answer

Umbilical vein

Answer

Common cardinal vein

Question 3

Mastoid process is which type of epiphysis?

Accepted Answer

Traction epiphysis

Answer

Pressure epiphysis

Answer

Atavistic epiphysis

Answer

Aberrant epiphysis

Question 4

How many ossification centers develop at the distal end of the humerus?

Accepted Answer

3

Answer

2

Answer

5

Answer

4

Question 5

Which of the following is NOT required for gluconeogenesis from lactate?

Accepted Answer

Transamination of pyruvate to alanine

Answer

Transport of lactate from muscle to liver

Answer

Conversion of lactate to pyruvate

Answer

None of the above

Question 6

Which of the following is not an androgen?

Accepted Answer

17α-hydroxyprogesterone

Answer

Testosterone

Answer

Dihydrotestosterone

Answer

Androstenedione

Question 7

What is the first permanent tooth to erupt?

Accepted Answer

First molar

Answer

First premolar

Answer

Second premolar

Answer

Second molar

Question 8

What is the complete classic triad of findings that defines Young's syndrome?

Accepted Answer

Azoospermia, bronchiectasis, and chronic sinusitis

Answer

Oligospermia, bronchiectasis, and chronic sinusitis

Answer

Azoospermia, asthma, and chronic rhinitis

Answer

Azoospermia, chronic bronchitis, and nasal polyps

Question 9

Which is not a feature of paroxysmal nocturnal hemoglobinuria?

Accepted Answer

Increased LAP score

Answer

Thrombocytopenia

Answer

Hemolysis

Answer

Thrombosis

Question 10

What is the name of the syndrome associated with the deletion of chromosome 22?

Accepted Answer

Di George syndrome

Answer

Down syndrome

Answer

Turner syndrome

Answer

Klinefelter syndrome

Answer

Prader-Willi syndrome

NEET-PG 2013

Anatomy

Biochemistry

Dental

Internal Medicine

Pathology

Psychiatry