NEET-PG 2013 - Anatomy Practice Questions

Q: Which of the following nerves is commonly damaged during McBurney's incision?

Iliohypogastric nerve. ***Iliohypogastric nerve*** - The **iliohypogastric nerve** is most commonly injured during **McBurney's incision** due to its superficial position and transverse course at the level of the incision. - Damage can lead to **numbness** or altered sensation in the suprapubic region, and sometimes **weakness of the lower abdominal wall**. *Subcostal nerve* - The **subcostal nerve** (T12) runs inferior to the 12th rib and is generally superior to the typical site of a McBurney's incision. - Injury to this nerve is less common during this procedure compared to the iliohypogastric and ilioinguinal nerves. *10th thoracic nerve* - The **10th thoracic nerve** (T10) provides sensation around the umbilicus. - While it contributes to innervation of the abdominal wall, its location is typically well above the area of a standard McBurney's incision, making injury unlikely. *11th thoracic nerve* - The **11th thoracic nerve** (T11) innervates the abdominal wall and is located superior to the typical incision site for appendectomy. - Injury to T11 during a McBurney's incision is uncommon as the nerve's course lies cephalad to the surgical field.

Q: During abdominal surgery under local anesthesia, the patient suddenly felt pain due to

Parietal peritoneum. ***Parietal peritoneum*** - The **parietal peritoneum** is richly innervated by somatic nerves (**spinal nerves**), making it highly sensitive to pain, pressure, and temperature. - When stimulated during surgery, even under local anesthesia which might not completely block deeper somatic nerves or if the local block is inadequate, it can cause the patient to suddenly feel **sharp, localized pain**. *Liver* - The liver itself has very few pain receptors in its parenchyma; pain from the liver typically arises from stretching of its fibrous capsule (**Glisson's capsule**). - This pain is usually dull and poorly localized, not the sudden, sharp pain typically experienced during surgical manipulation. *Intestines* - The intestines are primarily innervated by the **autonomic nervous system** and are sensitive to distension and ischemia, causing visceral pain, which is typically dull, crampy, and poorly localized. - They are generally not sensitive to cutting or burning, which are common surgical manipulations. *Visceral peritoneum* - The **visceral peritoneum** covers abdominal organs and is innervated by the autonomic nervous system, similar to the organs it covers. - Like the intestines, it is sensitive to stretch and ischemia, producing diffuse, poorly localized visceral pain rather than sharp, localized pain from surgical incision or manipulation.

Q: What is the bispinous diameter?

10.5 cm. ***10.5 cm*** - The **bispinous (interspinous) diameter** is the transverse diameter of the midpelvis, measured between the two ischial spines. [1] - A measurement of **10.5 cm** is the average and normal length for this diameter. [1] - This is the **narrowest diameter of the pelvis** and represents a critical measurement during labor, as it is the narrowest point through which the fetal head must pass. [1] *11.5 cm* - This measurement is typically associated with the **obstetric conjugate** at the pelvic inlet, not the midpelvis. - The bispinous diameter, being the narrowest transverse diameter of the pelvis, is normally shorter than 11.5 cm. *12 cm* - A 12 cm measurement is too wide for the **bispinous diameter**. - The **transverse diameter of the pelvic inlet** is approximately 13 cm, and the **transverse diameter of the pelvic outlet** is about 11 cm, but neither of these is the bispinous diameter. *11 cm* - While 11 cm is close, it is slightly larger than the typical average for the **bispinous diameter** of 10.5 cm. - The **transverse diameter of the outlet** is approximately 11 cm [2], but this is a different measurement at a different level of the pelvis.

Q: Root value of the thoracodorsal nerve

C6, C7, C8. ***C6, C7, C8*** - The **thoracodorsal nerve**, also known as the middle subscapular nerve, originates from the **posterior cord of the brachial plexus**. - Its specific root values are **C6, C7, and C8**, which supply motor innervation to the **latissimus dorsi muscle** [1]. - This nerve is one of the three subscapular nerves arising from the posterior cord [1]. *C5, C6, C7* - While these roots contribute to the **posterior cord**, the thoracodorsal nerve specifically arises from **C6, C7, C8**. - **C5** primarily contributes to the **upper and middle trunk** and is more associated with nerves like the **suprascapular** and **axillary nerves**. *C6, T1* - These root values contribute to various nerves of the **brachial plexus**, but not specifically the thoracodorsal nerve. - **T1** contributes mainly to the **medial cord** and its branches like the **ulnar nerve**, not the posterior cord from which the thoracodorsal nerve arises. *T1, T2* - These are typical root values for **intercostal nerves** and contribute to the **sympathetic trunk**, not the **brachial plexus** or its branches like the thoracodorsal nerve. - The brachial plexus predominantly arises from **C5 to T1 spinal nerve roots**, and **T2** is not part of the brachial plexus.

Q: In a 3 month fetus, characteristic feature seen is:

Nails are visible. ***Nails are visible*** - By the end of the **third month** (approximately 12 weeks), the fingers and toes are fully formed, and the beginnings of fingernails and toenails usually become visible. - This marks a significant developmental milestone in fetal maturation during the first trimester. *Meconium is present in the intestines* - **Meconium** begins to form during the **second trimester**, typically around weeks 12-16, with significant accumulation in the latter part of the second and throughout the third trimester. - While some gut movements occur earlier, the presence of well-formed meconium for defecation happens later in fetal development. *Anus formation begins* - The formation of the anus is part of the development of the **cloaca**, which begins much earlier, around the **4th to 7th gestational weeks**. - By 3 months, the anorectal canal is already well-differentiated, so its formation has already been completed. *Limb buds are present* - **Limb buds** appear very early in embryonic development, around the **end of the 4th week**. [1] - By 3 months, the limbs are already well-developed with distinct fingers and toes, so these structures would have passed the "bud" stage.

Q: What is the anatomical relation of the upper lacrimal punctum with respect to the lower punctum?

Superior. ***Superior*** - The **upper lacrimal punctum** is located slightly **superior** to the lower lacrimal punctum, which is the predominant anatomical relationship. - Additionally, the upper punctum is positioned slightly **lateral** (approximately 0.5-1mm) to the lower punctum, though the superior relationship is more clinically significant. - This arrangement facilitates efficient tear drainage into the lacrimal canaliculi and ultimately to the nasolacrimal duct. *Lateral* - While there is a slight **lateral offset** between the upper and lower puncta, this is not the primary or most significant anatomical relationship. - The **superior-inferior relationship** is the dominant spatial arrangement and is more relevant for clinical examination and cannulation procedures. *No relation* - The upper and lower lacrimal puncta have a precise anatomical relationship as paired openings into the **lacrimal canaliculi**. - They work together as part of the tear drainage system, positioned at the medial aspects of their respective eyelid margins. *Apposed* - The term **apposed** means being in direct contact or immediately adjacent, which does not describe the relationship between the puncta. - They are separated by the medial canthal area and located on different eyelid margins (upper vs. lower), not in direct apposition.

Q: Lesion of the marked structure affects all EXCEPT

Superior oblique. ***Superior oblique*** - The **superior oblique** muscle is innervated by the **trochlear nerve (CN IV)**. - A lesion affecting the **oculomotor nerve (CN III)**, which usually controls the marked structure, would therefore **not** affect the superior oblique. *Superior rectus* - The **superior rectus** muscle is innervated by the **oculomotor nerve (CN III)**. - A lesion of the oculomotor nerve would impair its function, leading to difficulty in **elevating** and **adducting** the eye. *Inferior oblique* - The **inferior oblique** muscle is innervated by the **oculomotor nerve (CN III)**. - Damage to this nerve would result in compromised function of the inferior oblique, affecting **extorsion** and **elevation** of the eye. *Medial rectus* - The **medial rectus** muscle is innervated by the **oculomotor nerve (CN III)**. - A lesion of the oculomotor nerve would lead to an inability to perform **adduction** (moving the eye inward).

Q: Which muscle originates from tendon of other muscle?

Lumbricals. Lumbricals - The lumbrical muscles are unique in the hand because they originate from the tendons of the flexor digitorum profundus (FDP), not from bone [1]. - This attachment allows them to flex the metacarpophalangeal (MCP) joints while extending the interphalangeal (IP) joints [1]. FCR - The flexor carpi radialis (FCR) muscle originates from the medial epicondyle of the humerus, a bony origin. - Its primary function is flexion and radial deviation of the wrist. Adductor pollicis - The adductor pollicis muscle has two heads, the oblique and transverse heads, both originating from various carpal bones and the third metacarpal. - It plays a crucial role in adducting the thumb. Palmaris longus - The palmaris longus muscle originates from the medial epicondyle of the humerus, similar to the FCR. - It contributes to wrist flexion and is absent in a significant portion of the population.

Q: Submandibular nodes are classified as

Level 1B neck nodes. ***Level 1B neck nodes*** - The **submandibular nodes** are located anterior to the posterior belly of the digastric muscle and lateral to the anterior belly of the digastric muscle, placing them within **Level 1B** of the neck lymph node classification [1]. - This level primarily drains the oral cavity, face, and submandibular gland [1]. *Level III neck nodes* - **Level III** nodes are the middle jugular nodes, located between the level of the hyoid bone and the cricoid cartilage. - These nodes are typically found along the **internal jugular vein** and drain structures such as the larynx, hypopharynx, and thyroid. *Level II neck nodes* - **Level II** nodes, or upper jugular nodes, are located from the skull base to the inferior border of the hyoid bone, along the internal jugular vein. - This level is further divided into Level IIA (anterior to the spinal accessory nerve) and Level IIB (posterior to the spinal accessory nerve) and drains structures like the nasopharynx, oropharynx, and parotid gland. *Level 1 A neck nodes* - **Level 1A** nodes refer to the **submental nodes**, which are located between the anterior bellies of the digastric muscles [1]. - These nodes primarily drain the central lower lip, floor of the mouth, anterior tongue, and chin [1].

Q: Which of the following nerves transmits impulses originating from the vestibular apparatus?

Cranial nerve VIII. ***Cranial nerve VIII*** - The **vestibulocochlear nerve (CN VIII)** is responsible for transmitting both auditory (cochlear branch) and balance (vestibular branch) information to the brain [1], [2]. - The **vestibular apparatus** in the inner ear detects head movements and position, and its impulses are carried by the vestibular part of CN VIII [2]. *Cranial nerve XI* - **Cranial nerve XI (Accessory nerve)** primarily controls the **sternocleidomastoid** and **trapezius muscles**, involved in head and shoulder movement. - It has no role in transmitting sensory information from the vestibular apparatus or the inner ear. *Cranial nerve VII* - **Cranial nerve VII (Facial nerve)** innervates the **muscles of facial expression**, carries taste sensation from the anterior two-thirds of the tongue, and supplies several glands. - It is not involved in transmitting impulses related to balance from the vestibular apparatus. *Cranial nerve II* - **Cranial nerve II (Optic nerve)** is responsible for **vision**, transmitting visual information from the retina to the brain. - It has no function related to the vestibular system or balance.

Question 1

Which of the following nerves is commonly damaged during McBurney's incision?

Accepted Answer

Iliohypogastric nerve

Answer

Subcostal nerve

Answer

11th thoracic nerve

Answer

10th thoracic nerve

Question 2

During abdominal surgery under local anesthesia, the patient suddenly felt pain due to

Accepted Answer

Parietal peritoneum

Answer

Liver

Answer

Intestines

Answer

Visceral peritoneum

Question 3

What is the bispinous diameter?

Accepted Answer

10.5 cm

Answer

11.5 cm

Answer

12 cm

Answer

11 cm

Question 4

Root value of the thoracodorsal nerve

Accepted Answer

C6, C7, C8

Answer

T1, T2

Answer

C5, C6, C7

Answer

C6, T1

Question 5

In a 3 month fetus, characteristic feature seen is:

Accepted Answer

Nails are visible

Answer

Meconium is present in the intestines.

Answer

Anus formation begins.

Answer

Limb buds are present.

Question 6

What is the anatomical relation of the upper lacrimal punctum with respect to the lower punctum?

Accepted Answer

Superior

Answer

Lateral

Answer

No relation

Answer

Apposed

Question 7

Lesion of the marked structure affects all EXCEPT

Accepted Answer

Superior oblique

Answer

Superior rectus

Answer

Inferior oblique

Answer

Medial rectus

Question 8

Which muscle originates from tendon of other muscle?

Accepted Answer

Lumbricals

Answer

FCR

Answer

Adductor pollicis

Answer

Palmaris longus

Question 9

Submandibular nodes are classified as

Accepted Answer

Level 1B neck nodes

Answer

Level III neck nodes

Answer

Level II neck nodes

Answer

Level 1A neck nodes

Question 10

Which of the following nerves transmits impulses originating from the vestibular apparatus?

Accepted Answer

Cranial nerve VIII

Answer

Cranial nerve XI

Answer

Cranial nerve VII

Answer

Cranial nerve II

NEET-PG 2013 — Anatomy