NEET-PG 2012 - Anatomy Practice Questions

Q: Which of the following is not a boundary of the triangle of auscultation?

Rhomboid major. ***Rhomboid major*** - The **rhomboid major** muscle forms the **floor** of the triangle of auscultation, not one of its boundaries. - Its function is to **retract** and **rotate** the scapula, anchoring it to the thoracic wall. *Trapezius* - The **trapezius** muscle forms the **superior** and **medial** boundary of the triangle of auscultation. - It defines the upper limit of this anatomical space on the back. *Scapula* - The **medial border of the scapula** forms the **lateral** boundary of the triangle of auscultation. - This bony landmark helps to delineate the outer edge of the triangle. *Latissimus dorsi* - The **latissimus dorsi** muscle forms the **inferior** boundary of the triangle of auscultation. - It defines the lower limit of this region, allowing for better sound transmission to the thoracic cavity.

Q: In patients with penile or urethral injury, Colle's fascia prevents extravasation of urine from spreading into which anatomical space?

Ischiorectal fossa. ***Ischiorectal fossa*** - Colle's fascia (superficial perineal fascia) is the membranous layer that defines the boundaries of the **superficial perineal space**. - When urethral injury occurs, urine extravasates into the superficial perineal space but is **prevented from spreading laterally and posteriorly** into the ischiorectal fossa because Colle's fascia fuses with the **ischiopubic rami** laterally and the **perineal membrane** posteriorly [1]. - The ischiorectal fossa is a space lateral to the **anal canal** that is separated from the superficial perineal space by these fascial attachments. *Superficial perineal space* - This is actually the space **into which** urine extravasates when penile or urethral injury occurs, not the space that is protected from extravasation [1]. - Colle's fascia forms the inferior boundary of this space, so urine collects here rather than being prevented from entering. *Abdomen* - Colle's fascia in the perineum is continuous with **Scarpa's fascia** of the anterior abdominal wall. - Due to this continuity, urine can actually **track superiorly** into the anterior abdominal wall along this fascial plane. - Therefore, Colle's fascia does NOT prevent spread to the abdomen. *None of the options* - This option is incorrect because Colle's fascia specifically prevents lateral and posterior spread into the ischiorectal fossa through its anatomical attachments.

Q: What is the consequence of tibial nerve injury/palsy?

Loss of plantar flexion. **Loss of plantar flexion** - The **tibial nerve** innervates the muscles of the **posterior compartment of the leg**, which are primarily responsible for **plantar flexion** of the foot. - Injury to this nerve directly impairs the function of muscles like the gastrocnemius, soleus, and tibialis posterior, leading to a significant loss of the ability to point the foot downwards. *Dorsiflexion of foot at ankle joint* - **Dorsiflexion** is primarily mediated by muscles in the **anterior compartment of the leg**, such as the tibialis anterior, which are innervated by the **deep fibular nerve**. - Tibial nerve injury would not directly affect these muscles or their function; rather, it leads to issues with the opposing action. *Loss of sensation of dorsum of foot* - Sensation to the **dorsum of the foot** is primarily supplied by the **superficial fibular nerve** (for most of the dorsum) and the **deep fibular nerve** (for the first web space). - While the tibial nerve provides sensation to the sole of the foot, it does not typically innervate the dorsum. *Paralysis of muscles of anterior compartment of leg* - The muscles of the **anterior compartment of the leg** (e.g., tibialis anterior, extensor digitorum longus, extensor hallucis longus) are innervated by the **deep fibular nerve**. - A tibial nerve injury would paralyze muscles in the posterior compartment, not the anterior compartment.

Q: Sensory supply of the palm is from which nerves?

Ulnar nerve and Median nerve. **Ulnar nerve and Median nerve** *(Correct)* - The **median nerve** provides sensory innervation to the lateral palm, including the thumb, index, middle, and radial half of the ring finger [1]. - The **ulnar nerve** supplies sensory innervation to the medial palm, including the little finger and the ulnar half of the ring finger [1]. - Together, these two nerves provide complete sensory coverage of the palm [1]. *Median nerve and Radial nerve* (Incorrect) - While the **median nerve** innervates a significant portion of the palm, the **radial nerve** primarily supplies the dorsal aspect of the hand and a small area of the thenar eminence, not the entire palm. - The radial nerve's sensory supply to the palm is usually limited to a very small area at the base of the thumb. - This combination does not provide complete palmar sensory coverage. *Radial nerve and ulnar nerve* (Incorrect) - The **radial nerve** mainly supplies the dorsum of the hand and digits, with minimal palmar contribution, making this option incorrect for primary palmar sensory supply. - The **ulnar nerve** does innervate part of the palm, but the combination with the radial nerve for complete palmar supply is inaccurate. - The median nerve, not the radial nerve, is the other major contributor to palmar sensation. *Musculocutaneous nerve and Radial nerve* (Incorrect) - The **musculocutaneous nerve** primarily innervates the lateral aspect of the forearm (as the lateral antebrachial cutaneous nerve) and does not contribute to the sensory supply of the palm. - The **radial nerve** also has a limited role in palmar sensation. - Neither of these nerves provides significant sensory innervation to the palm.

Q: Sympathetic supply to the heart arises from which of the following spinal segments?

T1 to T5. The preganglionic sympathetic fibers that innervate the heart originate from the lateral horns of the thoracic spinal segments T1 to T5. These fibers synapse in the cervical and upper thoracic sympathetic ganglia, from which postganglionic fibers extend to the heart. While there is some overlap, the primary and most significant sympathetic innervation to the heart stems predominantly from T1 to T5, making T2 to T6 a less precise answer. Including T6 would extend past the typical primary cardiac sympathetic innervation, which largely concludes at T5. This range is too caudal and largely beyond the principal segments providing sympathetic innervation to the heart. Segments T6-T8 are more involved in sympathetic supply to abdominal organs and other structures rather than direct cardiac control.

Q: Coronary sinus develops from?

Sinus venosus. Sinus venosus - The sinus venosus is a primordial cardiac chamber that receives venous blood from the body and placenta in the early embryonic heart. - The left horn of the sinus venosus loses its connection with the systemic venous circulation and becomes the coronary sinus, which drains most of the cardiac veins into the right atrium [1, 4]. Truncus arteriosus - The truncus arteriosus is the embryonic precursor to the ascending aorta and pulmonary trunk. - It does not contribute to the development of the coronary sinus. Conus - The conus (or conus cordis) is the outflow portion of the primitive ventricle and differentiates into the outflow tracts of the right (infundibulum) and left (aortic vestibule) ventricles. - It is not involved in the formation of the coronary sinus. AV canal - The atrioventricular (AV) canal connects the primitive atrium and ventricle and is crucial for the formation of the AV valves and septation of the heart chambers. - It does not directly develop into the coronary sinus.

Q: Which of the following is an operculated sulcus ?

Sylvian fissure (lateral sulcus). ***Sylvian fissure (lateral sulcus)*** - The **lateral sulcus**, also known as the Sylvian fissure, is a deep groove on the lateral surface of the brain that **separates the frontal and parietal lobes from the temporal lobe**. - It is considered an **operculated sulcus** because its banks contain the insula, which is a buried part of the cerebral cortex covered by the surrounding cortical folds called opercula. *Calcarine* - The **calcarine sulcus** is located on the medial surface of the occipital lobe, forming the primary visual cortex, and is not an operculated sulcus. - It delineates the **upper and lower banks of the visual cortex** and does not involve overlying cortical structures. *Lunate* - The **lunate sulcus** is found on the posterior part of the occipital lobe and is not typically described as an operculated sulcus. - It represents a boundary in the visual cortex, but its banks do not hide a buried cortical region like the insula. *Central* - The **central sulcus** (Rolandic fissure) separates the frontal lobe from the parietal lobe and is a prominent sulcus, but it is not operculated. - Its banks contain the **precentral gyrus** (primary motor cortex) and **postcentral gyrus** (primary somatosensory cortex) directly facing each other.

Q: Development of labia majora is from -

Genital swelling. ***Genital swelling*** - The **labia majora** develop from the **genital (labioscrotal) swellings** in females, which are homologous to the scrotum in males [3]. - These swellings enlarge and fuse anteriorly to form the mons pubis and posteriorly to form the posterior commissures of the labia majora. *Urogenital sinus* - The **urogenital sinus** gives rise to structures like the **bladder**, **urethra**, and parts of the **vagina** in females [2]. - It does not contribute to the formation of the external labial structures. *Mullerian duct* - The **Mullerian (paramesonephric) ducts** develop into the **fallopian tubes**, **uterus**, and the **upper third of the vagina** [1], [2]. - These structures are internal reproductive organs and do not form external genitalia like the labia majora. *Genital ridge* - The **genital ridge** is the embryonic precursor to the **gonads** (ovaries or testes). - It differentiates into either ovaries or testes and does not directly form external genital structures.

Q: Renal papilla opens into -

Minor calyx. ***Minor calyx*** - The **renal papilla** is the apex of the renal pyramid, which drains urine directly into a **minor calyx**. - Minor calyces then merge to form major calyces, eventually leading to the renal pelvis. *Cortex* - The **renal cortex** is the outer layer of the kidney, containing glomeruli and convoluted tubules, and does not directly receive urine from the papilla. - Urine is primarily formed and filtered in the cortex and then flows into the medulla. *Pyramid* - A **renal pyramid** is a conical structure within the renal medulla, and the renal papilla is its tip, but it doesn't open *into* the pyramid itself. - Instead, the pyramid *contains* the structures that contribute to the papilla. *Major calyx* - A **major calyx** is formed by the convergence of several minor calyces. - The renal papilla drains into the minor calyx, which then, in turn, drains into the major calyx.

Question 1

Which of the following is not a boundary of the triangle of auscultation?

Accepted Answer

Rhomboid major

Answer

Trapezius

Answer

Scapula

Answer

Latissimus dorsi

Question 2

In patients with penile or urethral injury, Colle's fascia prevents extravasation of urine from spreading into which anatomical space?

Accepted Answer

Ischiorectal fossa

Answer

Superficial perineal space

Answer

None of the options

Answer

Abdomen

Question 3

What is the consequence of tibial nerve injury/palsy?

Accepted Answer

Loss of plantar flexion

Answer

Dorsiflexion of foot at ankle joint

Answer

Loss of sensation of dorsum of foot

Answer

Paralysis of muscles of anterior compartment of leg

Question 4

Sensory supply of the palm is from which nerves?

Accepted Answer

Ulnar nerve and Median nerve

Answer

Median nerve and Radial nerve

Answer

Radial nerve and ulnar nerve

Answer

Musculocutaneous nerve and Radial nerve

Question 5

Which of the following statements provides the MOST COMPLETE description of sclerotome function during vertebral development?

Accepted Answer

The sclerotome surrounds the notochord and the neural tube during development.

Answer

The notochord forms the nucleus pulposus.

Answer

The sclerotome contributes to the formation of vertebral bodies.

Answer

The sclerotome surrounds the notochord.

Question 6

Sympathetic supply to the heart arises from which of the following spinal segments?

Accepted Answer

T1 to T5

Answer

T2 to T6

Answer

T3 to T7

Answer

T4 to T8

Question 7

Coronary sinus develops from?

Accepted Answer

Sinus venosus

Answer

Truncus arteriosus

Answer

Conus

Answer

AV canal

Question 8

Which of the following is an operculated sulcus ?

Accepted Answer

Sylvian fissure (lateral sulcus)

Answer

Lunate

Answer

Calcarine

Answer

Central

Question 9

Development of labia majora is from -

Accepted Answer

Genital swelling

Answer

Urogenital sinus

Answer

Mullerian duct

Answer

Genital ridge

Question 10

Renal papilla opens into -

Accepted Answer

Minor calyx

Answer

Cortex

Answer

Pyramid

Answer

Major calyx

NEET-PG 2012 — Anatomy