UPSC-CMS 2023 — Anatomy

Q: The inability to flex the index finger is a sign of

Median nerve injury. ***Median nerve injury*** - The **median nerve** innervates the **flexor digitorum superficialis** and the **flexor digitorum profundus** (radial half), which are responsible for flexing the index and middle fingers. [1] - Damage to this nerve at a high level (e.g., above the elbow) would impact these muscles, leading to an **inability to flex the index finger**. [1] *Radial nerve injury* - The **radial nerve** primarily innervates the **extensor muscles** of the arm and forearm. - Injury to this nerve would result in difficulty extending the wrist and fingers (e.g., **wrist drop**), not flexing them. *Ulnar nerve injury* - The **ulnar nerve** innervates the **flexor carpi ulnaris** and the **ulnar half of the flexor digitorum profundus** (ring and pinky finger). [1] - Damage would primarily affect the flexion of the ring and little fingers, as well as intrinsic hand muscles, leading to a **claw hand deformity**. *Dupuytren's contracture* - This condition involves **fibrosis and thickening of the palmar fascia**, causing the fingers (most commonly the ring and little fingers) to permanently flex towards the palm. - It is a **fibroproliferative disorder** of the hand, not a nerve injury, and typically affects flexibility in multiple fingers in a characteristic pattern, rather than a specific inability to flex one finger due to paralysis. [Practice more Anatomy PYQs on OnCourse]

Q: Inhaled foreign bodies are more likely to get lodged in the right main bronchus because

Right main bronchus is shorter, wider and nearly vertical. ***Right main bronchus is shorter, wider and nearly vertical*** - The **anatomical configuration** of the right main bronchus makes it a more direct continuation of the trachea. - Its **wider diameter** and **more vertical angle** allow foreign bodies to fall into it more easily due to gravity and airflow. *Left main bronchus is wider and shorter* - This statement is incorrect; the **left main bronchus** is actually **narrower and longer** than the right. - Its **more acute angle** stemming from the trachea also makes it less likely for foreign objects to lodge there directly. *Right main bronchus is shorter, narrower and lies horizontally in relation to trachea* - This statement is incorrect as the **right main bronchus** is indeed **shorter** but is **wider** and takes a **more vertical** course, not horizontal. - The description of being "narrower" and "horizontally" contradicts the anatomical characteristics that facilitate foreign body impaction. *Left main bronchus is narrow and longer* - This statement is anatomically correct for the left main bronchus; however, these characteristics make it **less likely** for foreign bodies to get lodged here. - The **narrower lumen** and **longer path**, combined with a more acute angle, make it a less direct route for inhaled objects. [Practice more Anatomy PYQs on OnCourse]

Q: The following are the branches of the anterior division of internal iliac artery except

Superior rectal artery. ***Superior rectal artery*** - This artery is a direct continuation of the **inferior mesenteric artery**, which is a branch of the **abdominal aorta**, not the internal iliac artery. - It supplies the **superior part of the rectum** and is not associated with the internal iliac artery's divisions. *Inferior vesical artery* - This artery typically arises from the **anterior division of the internal iliac artery** and supplies the **bladder** and male reproductive organs. - It is a correct branch of the anterior division, making it an incorrect answer to the "except" question. *Uterine artery* - The **uterine artery** is a significant branch of the **anterior division of the internal iliac artery** in females. - It supplies the **uterus**, vagina, and surrounding structures, confirming its origin from the anterior division. *Middle rectal artery* - This artery originates from the **anterior division of the internal iliac artery** and supplies the **middle portion of the rectum**. [1] - It is a recognized branch of the anterior division, so it is not the exception. [Practice more Anatomy PYQs on OnCourse]

Q: The inferior rectal artery is a branch of :

Internal pudendal artery. ***Internal pudendal artery*** - The **inferior rectal artery** is a key branch of the **internal pudendal artery**, supplying blood to the anal canal below the pectinate line. - This artery typically arises in the **ischioanal fossa** (also known as the ischiorectal fossa), providing vascularization to the external anal sphincter and perineal skin. *Inferior mesenteric artery* - The **inferior mesenteric artery** is responsible for supplying large intestine structures from the distal transverse colon to the superior part of the rectum [1]. - Its main branches are the **left colic artery**, **sigmoid arteries**, and **superior rectal artery**, none of which directly give rise to the inferior rectal artery [1]. *Internal iliac artery* - The **internal iliac artery** is a large artery that supplies many pelvic organs and the perineum; it gives off the **internal pudendal artery** as one of its terminal branches. - While it is the source of the internal pudendal artery, it does not directly branch into the inferior rectal artery. *Median sacral artery* - The **median sacral artery** is a small, unpaired artery that arises from the posterior aspect of the abdominal aorta just above its bifurcation. - It supplies structures in the posterior pelvic wall, such as the sacrum, coccyx, and adjacent posterior muscles but has no direct connection to the inferior rectal artery. [Practice more Anatomy PYQs on OnCourse]

8 Previous Year Questions with Answers & Explanations

Questions

All Subjects Anatomy (8)Biochemistry (3)Community Medicine (52)Dermatology (1)Forensic Medicine (2)Internal Medicine (29)Microbiology (4)Obstetrics and Gynecology (66)Ophthalmology (2)Orthopaedics (1)Pathology (9)Pediatrics (6)Pharmacology (3)Physiology (10)Psychiatry (1)Radiology (6)Surgery (24)

Match List-I with List-II and select the correct answer using the code given below the Lists: (Refer to the image below for the lists)

The inability to flex the index finger is a sign of

Inhaled foreign bodies are more likely to get lodged in the right main bronchus because

The following are the branches of the anterior division of internal iliac artery except

The inferior rectal artery is a branch of :

Which of the following statements with regard to Meckel's Diverticulum are correct? 1. It represents a persistent remnant of the vitellointestinal duct. 2. It is a true diverticulum of gastrointestinal tract. 3. It is most commonly found on anti-mesenteric border of ileum. 4. Heterotopic mucosa is present in 50-60% of patients. Select the correct answer using the code given below:

Which of the following set of muscles collectively form the muscle 'Levator Ani' that forms the pelvic floor ? 1. Puborectalis 2. Pubococcygeus 3. Sacrococcygeus 4. Iliococcygeus Select the correct answer using the code given below :

Blood supply to the uterus comes from which of the following arteries ? 1. Ovarian artery 2. Vaginal artery 3. Uterine artery 4. Inferior vesical artery Select the correct answer using the code given below :

UPSC-CMS 2023 - Anatomy UPSC-CMS Practice Questions and MCQs

Question 1: Match List-I with List-II and select the correct answer using the code given below the Lists: (Refer to the image below for the lists)

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

Explanation: ***A→4 B→3 C→2 D→1*** - **Atrial fibrillation** is characterized by **irregularly irregular rhythm** without distinct P waves, making the R-R interval highly variable. It is a supraventricular tachyarrhythmia, originating above the ventricles. - **Ventricular tachycardia** typically presents with a **wide QRS complex** (>0.12 s) and a **rapid, regular heart rate**, as it originates from the ventricles. - **Complete heart block** is characterized by complete dissociation between **P waves and QRS complexes**, meaning the atria and ventricles beat independently. This is reflected in an irregular P-P interval and a regular but slower R-R interval often due to an escape rhythm. - **Ventricular fibrillation** is an ECG emergency characterized by chaotic, **irregular electrical activity** and an absence of discernible P waves, QRS complexes, or T waves, leading to cardiac arrest. *A→4 B→3 C→1 D→2* - This option correctly matches A (Atrial fibrillation) with 4 (Irregular R-R interval without P waves) and B (Ventricular tachycardia) with 3 (Wide QRS complexes and regular rapid rate). However, it incorrectly matches C (Complete heart block) with 1 (Chaotic rhythm) and D (Ventricular fibrillation) with 2 (Dissociation of P and QRS waves). - **Complete heart block** involves **dissociation of P and QRS waves**, and **Ventricular fibrillation** is defined by a **chaotic rhythm**, not the other way around as suggested by C→1 and D→2. *A→3 B→2 C→4 D→1* - This option incorrectly matches A (Atrial fibrillation) with 3 (Wide QRS complexes and regular rapid rate), which describes ventricular tachycardia. - It also incorrectly matches C (Complete heart block) with 4 (Irregular R-R interval without P waves) and D (Ventricular fibrillation) with 1 (Chaotic rhythm), instead of the correct associations. *A→3 B→2 C→1 D→4* - This option incorrectly matches A (Atrial fibrillation) with 3 (Wide QRS complexes and regular rapid rate) which is characteristic of ventricular tachycardia. - It also incorrectly matches B (Ventricular tachycardia) with 2 (Dissociation of P and QRS waves), which is a characteristic of complete heart block, not ventricular tachycardia.

Question 2: The inability to flex the index finger is a sign of

A. Median nerve injury (Correct Answer)
B. Radial nerve injury
C. Ulnar nerve injury
D. Dupuytren's contracture

Explanation: ***Median nerve injury*** - The **median nerve** innervates the **flexor digitorum superficialis** and the **flexor digitorum profundus** (radial half), which are responsible for flexing the index and middle fingers. [1] - Damage to this nerve at a high level (e.g., above the elbow) would impact these muscles, leading to an **inability to flex the index finger**. [1] *Radial nerve injury* - The **radial nerve** primarily innervates the **extensor muscles** of the arm and forearm. - Injury to this nerve would result in difficulty extending the wrist and fingers (e.g., **wrist drop**), not flexing them. *Ulnar nerve injury* - The **ulnar nerve** innervates the **flexor carpi ulnaris** and the **ulnar half of the flexor digitorum profundus** (ring and pinky finger). [1] - Damage would primarily affect the flexion of the ring and little fingers, as well as intrinsic hand muscles, leading to a **claw hand deformity**. *Dupuytren's contracture* - This condition involves **fibrosis and thickening of the palmar fascia**, causing the fingers (most commonly the ring and little fingers) to permanently flex towards the palm. - It is a **fibroproliferative disorder** of the hand, not a nerve injury, and typically affects flexibility in multiple fingers in a characteristic pattern, rather than a specific inability to flex one finger due to paralysis.

Question 3: Inhaled foreign bodies are more likely to get lodged in the right main bronchus because

A. Right main bronchus is shorter, wider and nearly vertical (Correct Answer)
B. Left main bronchus is wider and shorter
C. Right main bronchus is shorter, narrower and lies horizontally in relation to trachea
D. Left main bronchus is narrow and longer

Explanation: ***Right main bronchus is shorter, wider and nearly vertical*** - The **anatomical configuration** of the right main bronchus makes it a more direct continuation of the trachea. - Its **wider diameter** and **more vertical angle** allow foreign bodies to fall into it more easily due to gravity and airflow. *Left main bronchus is wider and shorter* - This statement is incorrect; the **left main bronchus** is actually **narrower and longer** than the right. - Its **more acute angle** stemming from the trachea also makes it less likely for foreign objects to lodge there directly. *Right main bronchus is shorter, narrower and lies horizontally in relation to trachea* - This statement is incorrect as the **right main bronchus** is indeed **shorter** but is **wider** and takes a **more vertical** course, not horizontal. - The description of being "narrower" and "horizontally" contradicts the anatomical characteristics that facilitate foreign body impaction. *Left main bronchus is narrow and longer* - This statement is anatomically correct for the left main bronchus; however, these characteristics make it **less likely** for foreign bodies to get lodged here. - The **narrower lumen** and **longer path**, combined with a more acute angle, make it a less direct route for inhaled objects.

Question 4: The following are the branches of the anterior division of internal iliac artery except

A. Inferior vesical artery
B. Uterine artery
C. Superior rectal artery (Correct Answer)
D. Middle rectal artery

Explanation: ***Superior rectal artery*** - This artery is a direct continuation of the **inferior mesenteric artery**, which is a branch of the **abdominal aorta**, not the internal iliac artery. - It supplies the **superior part of the rectum** and is not associated with the internal iliac artery's divisions. *Inferior vesical artery* - This artery typically arises from the **anterior division of the internal iliac artery** and supplies the **bladder** and male reproductive organs. - It is a correct branch of the anterior division, making it an incorrect answer to the "except" question. *Uterine artery* - The **uterine artery** is a significant branch of the **anterior division of the internal iliac artery** in females. - It supplies the **uterus**, vagina, and surrounding structures, confirming its origin from the anterior division. *Middle rectal artery* - This artery originates from the **anterior division of the internal iliac artery** and supplies the **middle portion of the rectum**. [1] - It is a recognized branch of the anterior division, so it is not the exception.

Question 5: The inferior rectal artery is a branch of :

A. Internal pudendal artery (Correct Answer)
B. Inferior mesenteric artery
C. Internal iliac artery
D. Median sacral artery

Explanation: ***Internal pudendal artery*** - The **inferior rectal artery** is a key branch of the **internal pudendal artery**, supplying blood to the anal canal below the pectinate line. - This artery typically arises in the **ischioanal fossa** (also known as the ischiorectal fossa), providing vascularization to the external anal sphincter and perineal skin. *Inferior mesenteric artery* - The **inferior mesenteric artery** is responsible for supplying large intestine structures from the distal transverse colon to the superior part of the rectum [1]. - Its main branches are the **left colic artery**, **sigmoid arteries**, and **superior rectal artery**, none of which directly give rise to the inferior rectal artery [1]. *Internal iliac artery* - The **internal iliac artery** is a large artery that supplies many pelvic organs and the perineum; it gives off the **internal pudendal artery** as one of its terminal branches. - While it is the source of the internal pudendal artery, it does not directly branch into the inferior rectal artery. *Median sacral artery* - The **median sacral artery** is a small, unpaired artery that arises from the posterior aspect of the abdominal aorta just above its bifurcation. - It supplies structures in the posterior pelvic wall, such as the sacrum, coccyx, and adjacent posterior muscles but has no direct connection to the inferior rectal artery.

Question 6: Which of the following statements with regard to Meckel's Diverticulum are correct? 1. It represents a persistent remnant of the vitellointestinal duct. 2. It is a true diverticulum of gastrointestinal tract. 3. It is most commonly found on anti-mesenteric border of ileum. 4. Heterotopic mucosa is present in 50-60% of patients. Select the correct answer using the code given below:

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

Explanation: ***Option: 1, 2 and 3 (Correct Answer)*** - **Statement 1 is correct:** Meckel's diverticulum is a **congenital anomaly** resulting from incomplete obliteration of the **vitellointestinal (vitelline) duct**, which connects the midgut to the yolk sac during embryonic development [1]. - **Statement 2 is correct:** It is a **true diverticulum** because it contains all three layers of the intestinal wall: mucosa, submucosa, and muscularis propria (unlike false diverticula which only contain mucosa and submucosa). - **Statement 3 is correct:** It arises from the **anti-mesenteric border of the ileum**, typically within 60-100 cm proximal to the ileocecal valve [1]. - **Statement 4 is incorrect:** Heterotopic mucosa (most commonly gastric mucosa, followed by pancreatic tissue) is present in approximately **20-30% of all Meckel's diverticula**. The 50-60% figure applies specifically to **symptomatic cases**, not all patients with the condition [1]. *Option: 1, 3 and 4* - While statements 1 and 3 are correct, statement 4 overstates the prevalence of heterotopic mucosa in the general population with Meckel's diverticulum [1]. - Additionally, this option excludes statement 2, which is definitively correct and represents an essential characteristic of Meckel's as a true diverticulum. *Option: 1, 2 and 4* - Statements 1 and 2 are correct, but statement 4's percentage for heterotopic mucosa (50-60%) is too high for the overall population [1]. - The actual prevalence of heterotopic mucosa is **20-30% in all cases**, though it is found in the majority of symptomatic presentations. *Option: 1 and 3* - While statements 1 and 3 are correct, this option incorrectly excludes statement 2. - Statement 2 is unequivocally correct: Meckel's is a **true diverticulum** with all intestinal wall layers, which distinguishes it from false diverticula.

Question 7: Which of the following set of muscles collectively form the muscle 'Levator Ani' that forms the pelvic floor ? 1. Puborectalis 2. Pubococcygeus 3. Sacrococcygeus 4. Iliococcygeus Select the correct answer using the code given below :

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

Explanation: ***1, 2 and 4*** - The **levator ani** muscle group is comprised of three distinct muscles: **puborectalis**, **pubococcygeus**, and **iliococcygeus** [1]. - These muscles collectively form the main component of the **pelvic floor**, supporting pelvic organs and controlling continence [1]. - The levator ani, together with the coccygeus muscle, forms the **pelvic diaphragm**. *2, 3 and 4* - This option incorrectly includes the **sacrococcygeus** muscle, which is not part of the **levator ani** group. - The **sacrococcygeus** is a small, vestigial muscle found anterior to the sacrum and coccyx, and is separate from the pelvic diaphragm. - It excludes the **puborectalis**, which is an essential component of the levator ani [1]. *1, 3 and 4* - This option incorrectly includes the **sacrococcygeus** muscle, which is not a component of the **levator ani**. - It excludes the **pubococcygeus**, a major and essential component of the **levator ani** complex, critical for maintaining pelvic floor integrity and function [1]. *1, 2 and 3* - This option incorrectly includes the **sacrococcygeus** muscle and excludes the **iliococcygeus**. - The **iliococcygeus** muscle is a distinct and recognized part of the **levator ani** alongside the puborectalis and pubococcygeus [1].

Question 8: Blood supply to the uterus comes from which of the following arteries ? 1. Ovarian artery 2. Vaginal artery 3. Uterine artery 4. Inferior vesical artery Select the correct answer using the code given below :

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

Explanation: ***1, 2 and 3*** - The **uterine artery** is the primary blood supply to the uterus, originating from the internal iliac artery, and is crucial for uterine nutrition [1]. - The **ovarian artery** (a branch of the aorta) also contributes to the blood supply, forming anastomoses with the uterine artery, especially at the cornua [1]. - The **vaginal artery**, a branch of the internal iliac artery, forms anastomoses with the cervical branches of the uterine artery, providing additional blood supply to the lower uterus and cervix [1]. *2, 3 and 4* - This option incorrectly includes the **inferior vesical artery** as a direct supply to the uterus while omitting the ovarian artery, which is a significant contributor. - While the **inferior vesical artery** supplies the bladder and lower ureter, its direct anastomoses sufficient for uterine perfusion are limited. *1, 3 and 4* - This choice incorrectly includes the **inferior vesical artery** as a direct significant uterine supply and omits the **vaginal artery**, which provides relevant anastomoses to the lower uterus. - The **inferior vesical artery** primarily supplies the bladder and does not have a major, direct contribution to the main body of the uterus [2]. *1, 2 and 4* - This option incorrectly includes the **inferior vesical artery** as a primary or significant contributor while omitting the **uterine artery**, which is the main arterial supply to the uterus. - The **uterine artery** is essential for uterine function, and its absence from this selection makes the option incorrect from a physiological standpoint.