UPSC-CMS 2010 — Anatomy

Q: Dysphagia lusoria is a condition which results from

aberrant right subclavian artery. ***aberrant right subclavian artery*** - Dysphagia lusoria is specifically caused by compression of the **esophagus** by an **aberrant right subclavian artery** [2]. - This congenital anomaly involves the right subclavian artery arising from the distal aortic arch and passing behind the esophagus [2]. *oesophageal atresia* - **Oesophageal atresia** is a congenital condition where the esophagus ends in a blind pouch, preventing food from reaching the stomach [1]. - It usually presents in neonates with **vomiting** and **choking** during feeds, not progressive dysphagia in an adult [1]. *oesophageal web* - An **oesophageal web** is a thin, eccentric protrusion of normal esophageal tissue into the lumen, typically causing intermittent dysphagia to solids. - While it causes dysphagia, it is a structural abnormality within the esophageal lumen, not external compression. *corrosive stricture* - A **corrosive stricture** results from chemical burns to the esophagus, leading to scarring and narrowing of the lumen. - This is an acquired condition with a clear history of corrosive ingestion, unlike the congenital anomaly seen in dysphagia lusoria. [Practice more Anatomy PYQs on OnCourse]

Q: The lungs are derived from an out-pouching of the primitive foregut during which period of intrauterine life?

4th week. ***4th week*** - The **respiratory diverticulum (lung bud)** appears as a ventral out-pouching from the **primitive foregut** at approximately **26-28 days** of development, which falls in the **4th week** of intrauterine life [1]. - This marks the beginning of the respiratory system's development, initiating the formation of the **larynx**, **trachea**, **bronchi**, and **lungs** [1]. - The lung bud forms from the foregut endoderm and subsequently divides into the **right and left bronchial buds**. *3rd week* - During the third week, **gastrulation** occurs with the formation of the three germ layers (ectoderm, mesoderm, endoderm). - The **primitive gut tube** begins to form toward the end of the third week through **lateral and cranio-caudal folding**, but the respiratory diverticulum has not yet appeared. - The lung bud out-pouching occurs later, around day 26-28 of the fourth week. *5th week* - By the fifth week, the **laryngotracheal tube** has separated from the foregut via the **tracheoesophageal septum**. - The main **bronchi** continue to elongate and branch into **secondary (lobar) bronchi**. - The initial formation of the lung bud precedes this developmental stage. *6th week* - By the sixth week, the **bronchial tree** undergoes further branching with the formation of **tertiary (segmental) bronchi**. - The **pseudoglandular stage** of lung development is underway, with continued airway differentiation. - This represents a later stage of respiratory development, well after the initial lung bud formation [1]. [Practice more Anatomy PYQs on OnCourse]

Q: Consider the following statements with reference to scalp : 1. The blood vessels lie within dense connective tissue. 2. The anterior scalp is supplied by supraorbital and supratrochlear vessels. 3. The lateral and posterior scalp is supplied by superficial temporal, posterior auricular and occipital arteries. Which of the statements given above are correct?

1, 2 and 3. ***1, 2 and 3*** - All three statements provide accurate anatomical details regarding the scalp's structure and blood supply. The specific arrangement of vessels within the **dense connective tissue** and the listed arterial branches are correct. - The scalp is known for its rich vascularity and its five distinct layers, with the **dense connective tissue** layer anchoring the vessels, and a broad arterial supply covering all regions. *2 and 3 only* - This option is incorrect because statement 1, regarding the blood vessels lying within **dense connective tissue**, is also a correct anatomical fact. - Omitting statement 1 overlooks a crucial structural characteristic of the scalp layers, specifically the second layer (C for connective tissue). *1 and 3 only* - This option is incorrect because statement 2, detailing the supply of the anterior scalp by **supraorbital** and **supratrochlear vessels**, is also accurate. - Excluding statement 2 means ignoring a key component of the arterial supply to the anterior region of the scalp. *1 and 2 only* - This option is incorrect because statement 3, which describes the blood supply to the lateral and posterior scalp by the **superficial temporal**, **posterior auricular**, and **occipital arteries**, is also correct. - Failing to include statement 3 results in an incomplete description of the scalp's extensive and varied arterial network. [Practice more Anatomy PYQs on OnCourse]

Q: The transition between the stomach and duodenum is marked by

vein of Mayo. The transition between the stomach and duodenum is marked by ***vein of Mayo*** - The **vein of Mayo** (also known as the **prepyloric vein**) is a consistent landmark located on the anterior surface of the **pylorus**, making it a reliable surgical indicator for the gastroduodenal junction. - Its presence signifies the anatomical boundary between the **stomach** and the **duodenum** (specifically, the pylorus and duodenal bulb). *incisura* - The **incisura angularis** is a prominent anatomical landmark on the lesser curvature of the stomach, representing the junction between the body and the pyloric antrum of the stomach. It is shown as a major division in the anatomy of the stomach [1]. - It is located within the stomach itself and does not mark the transition to the duodenum. *hepatoduodenal ligament* - The **hepatoduodenal ligament** is part of the lesser omentum that connects the liver to the duodenum. - While it is anatomically close, it is a peritoneal fold containing structures like the portal triad, not a direct landmark for the gastroduodenal junction. *gastroduodenal artery* - The **gastroduodenal artery** is a major artery that branches from the common hepatic artery and supplies portions of the stomach and duodenum. - It is an important blood vessel in the region but does not serve as an anatomical surface landmark for the transition between the stomach and duodenum. [Practice more Anatomy PYQs on OnCourse]

Q: The true conjugate of the pelvic brim measures

11.5 cm. ***11.5 cm*** - The **true conjugate (conjugata vera)** is the anteroposterior diameter of the pelvic inlet, measured from the **posterior superior margin** of the pubic symphysis to the sacral promontory. [1] - It typically measures **11 cm** (range 10.5-11.5 cm), making 11.5 cm the most accurate answer among the given options. [1] - The true conjugate **cannot be measured clinically** but can be estimated by subtracting 1.5 cm from the diagonal conjugate. [1] - It is **distinct from** the obstetric conjugate, which is slightly shorter at 10.5 cm. *10.5 cm* - This measurement corresponds to the **obstetric conjugate**, not the true conjugate. - The obstetric conjugate is measured from the **most prominent point** on the posterior surface of the pubic symphysis (not the superior margin) to the sacral promontory. - While clinically important as the shortest fixed AP diameter through which the fetal head must pass, it is a **different measurement** from the true conjugate. *12.5 cm* - This value corresponds to the **diagonal conjugate**, which is the only conjugate diameter that can be measured clinically. - It is measured from the **lower border** of the symphysis pubis to the sacral promontory during pelvic examination. - The true conjugate is estimated by subtracting 1.5-2 cm from the diagonal conjugate (12.5 - 1.5 = 11 cm). *13.5 cm* - This measurement is considerably **larger** than any standard pelvic conjugate diameter. - It does not correspond to any clinically relevant pelvic measurement and would represent an unusually spacious pelvic inlet. [Practice more Anatomy PYQs on OnCourse]

6 Previous Year Questions with Answers & Explanations

Questions

All Subjects Anatomy (6)Biochemistry (2)Community Medicine (24)ENT (1)Forensic Medicine (1)Internal Medicine (7)Microbiology (3)Obstetrics and Gynecology (28)Ophthalmology (1)Orthopaedics (1)Pathology (8)Pediatrics (4)Pharmacology (9)Physiology (2)Radiology (4)Surgery (10)

Dysphagia lusoria is a condition which results from

The lungs are derived from an out-pouching of the primitive foregut during which period of intrauterine life?

Consider the following statements with reference to scalp : 1. The blood vessels lie within dense connective tissue. 2. The anterior scalp is supplied by supraorbital and supratrochlear vessels. 3. The lateral and posterior scalp is supplied by superficial temporal, posterior auricular and occipital arteries. Which of the statements given above are correct?

The transition between the stomach and duodenum is marked by

The true conjugate of the pelvic brim measures

Before puberty, what is the ratio between the cervical length and uterine body?

UPSC-CMS 2010 - Anatomy UPSC-CMS Practice Questions and MCQs

Question 1: Dysphagia lusoria is a condition which results from

A. oesophageal atresia
B. aberrant right subclavian artery (Correct Answer)
C. oesophageal web
D. corrosive stricture

Explanation: ***aberrant right subclavian artery*** - Dysphagia lusoria is specifically caused by compression of the **esophagus** by an **aberrant right subclavian artery** [2]. - This congenital anomaly involves the right subclavian artery arising from the distal aortic arch and passing behind the esophagus [2]. *oesophageal atresia* - **Oesophageal atresia** is a congenital condition where the esophagus ends in a blind pouch, preventing food from reaching the stomach [1]. - It usually presents in neonates with **vomiting** and **choking** during feeds, not progressive dysphagia in an adult [1]. *oesophageal web* - An **oesophageal web** is a thin, eccentric protrusion of normal esophageal tissue into the lumen, typically causing intermittent dysphagia to solids. - While it causes dysphagia, it is a structural abnormality within the esophageal lumen, not external compression. *corrosive stricture* - A **corrosive stricture** results from chemical burns to the esophagus, leading to scarring and narrowing of the lumen. - This is an acquired condition with a clear history of corrosive ingestion, unlike the congenital anomaly seen in dysphagia lusoria.

Question 2: The lungs are derived from an out-pouching of the primitive foregut during which period of intrauterine life?

A. 3rd week
B. 5th week
C. 4th week (Correct Answer)
D. 6th week

Explanation: ***4th week*** - The **respiratory diverticulum (lung bud)** appears as a ventral out-pouching from the **primitive foregut** at approximately **26-28 days** of development, which falls in the **4th week** of intrauterine life [1]. - This marks the beginning of the respiratory system's development, initiating the formation of the **larynx**, **trachea**, **bronchi**, and **lungs** [1]. - The lung bud forms from the foregut endoderm and subsequently divides into the **right and left bronchial buds**. *3rd week* - During the third week, **gastrulation** occurs with the formation of the three germ layers (ectoderm, mesoderm, endoderm). - The **primitive gut tube** begins to form toward the end of the third week through **lateral and cranio-caudal folding**, but the respiratory diverticulum has not yet appeared. - The lung bud out-pouching occurs later, around day 26-28 of the fourth week. *5th week* - By the fifth week, the **laryngotracheal tube** has separated from the foregut via the **tracheoesophageal septum**. - The main **bronchi** continue to elongate and branch into **secondary (lobar) bronchi**. - The initial formation of the lung bud precedes this developmental stage. *6th week* - By the sixth week, the **bronchial tree** undergoes further branching with the formation of **tertiary (segmental) bronchi**. - The **pseudoglandular stage** of lung development is underway, with continued airway differentiation. - This represents a later stage of respiratory development, well after the initial lung bud formation [1].

Question 3: Consider the following statements with reference to scalp : 1. The blood vessels lie within dense connective tissue. 2. The anterior scalp is supplied by supraorbital and supratrochlear vessels. 3. The lateral and posterior scalp is supplied by superficial temporal, posterior auricular and occipital arteries. Which of the statements given above are correct?

A. 2 and 3 only
B. 1 and 3 only
C. 1, 2 and 3 (Correct Answer)
D. 1 and 2 only

Explanation: ***1, 2 and 3*** - All three statements provide accurate anatomical details regarding the scalp's structure and blood supply. The specific arrangement of vessels within the **dense connective tissue** and the listed arterial branches are correct. - The scalp is known for its rich vascularity and its five distinct layers, with the **dense connective tissue** layer anchoring the vessels, and a broad arterial supply covering all regions. *2 and 3 only* - This option is incorrect because statement 1, regarding the blood vessels lying within **dense connective tissue**, is also a correct anatomical fact. - Omitting statement 1 overlooks a crucial structural characteristic of the scalp layers, specifically the second layer (C for connective tissue). *1 and 3 only* - This option is incorrect because statement 2, detailing the supply of the anterior scalp by **supraorbital** and **supratrochlear vessels**, is also accurate. - Excluding statement 2 means ignoring a key component of the arterial supply to the anterior region of the scalp. *1 and 2 only* - This option is incorrect because statement 3, which describes the blood supply to the lateral and posterior scalp by the **superficial temporal**, **posterior auricular**, and **occipital arteries**, is also correct. - Failing to include statement 3 results in an incomplete description of the scalp's extensive and varied arterial network.

Question 4: The transition between the stomach and duodenum is marked by

A. vein of Mayo (Correct Answer)
B. incisura
C. hepatoduodenal ligament
D. gastroduodenal artery

Explanation: The transition between the stomach and duodenum is marked by ***vein of Mayo*** - The **vein of Mayo** (also known as the **prepyloric vein**) is a consistent landmark located on the anterior surface of the **pylorus**, making it a reliable surgical indicator for the gastroduodenal junction. - Its presence signifies the anatomical boundary between the **stomach** and the **duodenum** (specifically, the pylorus and duodenal bulb). *incisura* - The **incisura angularis** is a prominent anatomical landmark on the lesser curvature of the stomach, representing the junction between the body and the pyloric antrum of the stomach. It is shown as a major division in the anatomy of the stomach [1]. - It is located within the stomach itself and does not mark the transition to the duodenum. *hepatoduodenal ligament* - The **hepatoduodenal ligament** is part of the lesser omentum that connects the liver to the duodenum. - While it is anatomically close, it is a peritoneal fold containing structures like the portal triad, not a direct landmark for the gastroduodenal junction. *gastroduodenal artery* - The **gastroduodenal artery** is a major artery that branches from the common hepatic artery and supplies portions of the stomach and duodenum. - It is an important blood vessel in the region but does not serve as an anatomical surface landmark for the transition between the stomach and duodenum.

Question 5: The true conjugate of the pelvic brim measures

A. 11.5 cm (Correct Answer)
B. 12.5 cm
C. 13.5 cm
D. 10.5 cm

Explanation: ***11.5 cm*** - The **true conjugate (conjugata vera)** is the anteroposterior diameter of the pelvic inlet, measured from the **posterior superior margin** of the pubic symphysis to the sacral promontory. [1] - It typically measures **11 cm** (range 10.5-11.5 cm), making 11.5 cm the most accurate answer among the given options. [1] - The true conjugate **cannot be measured clinically** but can be estimated by subtracting 1.5 cm from the diagonal conjugate. [1] - It is **distinct from** the obstetric conjugate, which is slightly shorter at 10.5 cm. *10.5 cm* - This measurement corresponds to the **obstetric conjugate**, not the true conjugate. - The obstetric conjugate is measured from the **most prominent point** on the posterior surface of the pubic symphysis (not the superior margin) to the sacral promontory. - While clinically important as the shortest fixed AP diameter through which the fetal head must pass, it is a **different measurement** from the true conjugate. *12.5 cm* - This value corresponds to the **diagonal conjugate**, which is the only conjugate diameter that can be measured clinically. - It is measured from the **lower border** of the symphysis pubis to the sacral promontory during pelvic examination. - The true conjugate is estimated by subtracting 1.5-2 cm from the diagonal conjugate (12.5 - 1.5 = 11 cm). *13.5 cm* - This measurement is considerably **larger** than any standard pelvic conjugate diameter. - It does not correspond to any clinically relevant pelvic measurement and would represent an unusually spacious pelvic inlet.

Question 6: Before puberty, what is the ratio between the cervical length and uterine body?

A. 1 : 2
B. 2 : 1 (Correct Answer)
C. 1 : 3
D. 1 : 4

Explanation: **2:1 (Correct Answer)** - Before puberty, the **cervix** is proportionally much longer than the **uterine body**, with a typical ratio of 2:1 (cervix:body) [1]. - This anatomical ratio changes significantly after puberty due to hormonal influences causing the uterine body to grow more rapidly. *1:2 (Incorrect)* - This ratio of 1:2, where the uterine body is longer than the cervix, is characteristic of the **post-pubertal** and **reproductive years** [1]. - It reflects the increased growth and development of the uterine corpus under the influence of hormones like **estrogen**. *1:3 (Incorrect)* - This ratio is not typical at any stage of uterine development, as the uterine body generally does not become three times the length of the cervix. - It represents an **unusual disproportion** in uterine-cervical length. *1:4 (Incorrect)* - This ratio is also not a standard physiological proportion for uterine-cervical length at any developmental stage. - Such an extreme disproportion would likely indicate an **anomalous uterine development**.