NEET-PG 2015 - Anatomy Practice Questions

Q: Which artery passes through the anatomical snuffbox?

Radial artery. ***Radial artery*** - The **radial artery** is palpable within the **anatomical snuffbox**, as it courses over the scaphoid and trapezium bones towards the deep palmar arch. - This location is clinically significant for feeling the pulse and is vulnerable to injury, especially during **scaphoid fractures**. *Brachial artery* - The **brachial artery** is found in the **arm**, typically running in the cubital fossa, well proximal to the anatomical snuffbox. - It bifurcates into the radial and ulnar arteries at the level of the elbow, not within the wrist structures. *Ulnar artery* - The **ulnar artery** typically lies on the **medial side of the forearm** and wrist, contributing to the superficial palmar arch. - It does not pass through the anatomical snuffbox, which is located on the lateral aspect of the wrist. *Interosseus artery* - The **interosseus arteries** (anterior and posterior) run between the radius and ulna in the forearm, supplying muscles and bones. - These arteries are deep within the forearm compartments and do not traverse the superficial anatomical snuffbox at the wrist.

Q: Which is the largest nerve that exits the pelvis through the greater sciatic foramen?

Sciatic nerve. ***Sciatic nerve*** - The **sciatic nerve** is the largest nerve in the human body, formed from the sacral plexus, and it is indeed the largest structure that passes through the **greater sciatic foramen** as it descends into the posterior thigh. - It supplies motor and sensory innervation to the posterior thigh, lower leg, and foot. *Superior gluteal artery* - The superior gluteal artery exits the pelvis through the **greater sciatic foramen** above the piriformis muscle. - While significant, it is an artery and not a nerve, and it is not the largest structure passing through this foramen. *Inferior gluteal artery* - The inferior gluteal artery also exits the pelvis via the **greater sciatic foramen**, inferior to the piriformis muscle. - Like the superior gluteal artery, it is an arterial structure and not a nerve, and it is not the largest structure in the foramen. *Piriformis muscle* - The **piriformis muscle** originates inside the pelvis and passes through the **greater sciatic foramen** to insert on the greater trochanter of the femur. - Although it occupies a significant portion of the foramen, it is a muscle, not a nerve, and the sciatic nerve is the largest nerve exiting this aperture.

Q: Inversion and eversion of foot occurs at which joint

Subtalar. ***Subtalar*** - The **subtalar joint** (talocalcaneal joint) is primarily responsible for **inversion** and **eversion** movements of the foot. - **Inversion** involves tilting the sole of the foot medially (turning inward), while **eversion** involves tilting the sole laterally (turning outward). - This joint allows the foot to **adapt to uneven surfaces** and plays a crucial role in the biomechanics of walking and running. - The subtalar joint is essential for shock absorption and balance during gait. *Ankle* - The **ankle joint** (talocrural joint) is a hinge joint primarily responsible for **dorsiflexion** and **plantarflexion** of the foot. - It allows moving the foot up and down but has minimal contribution to inversion and eversion. *Tarso-metatarsal* - The **tarso-metatarsal joints** (Lisfranc joints) connect the tarsal bones to the metatarsal bones. - These joints contribute primarily to the **stability and arch integrity** of the foot, with minimal movement capacity. - They allow slight gliding movements but not significant inversion or eversion. *None of the options* - This option is incorrect because the **subtalar joint** is indeed the primary joint responsible for inversion and eversion of the foot. - Understanding foot joint biomechanics is essential for diagnosing gait abnormalities, ankle sprains, and foot pathologies.

Q: Which of the following statements about the femoral triangle is NOT true?

Floor is formed by adductor longus. ***Floor is formed by adductor longus*** - The floor of the femoral triangle is actually formed by the **iliopsoas** laterally and the **pectineus** medially. - The **adductor longus** forms part of the medial boundary of the femoral triangle, not its floor. - This is the INCORRECT statement (correct answer for a "NOT true" question). *Contains the femoral vessels* - The femoral triangle is a crucial anatomical space containing the **femoral artery**, **femoral vein**, and **femoral nerve**. - These structures are organized from lateral to medial as nerve, artery, vein (NAVY). *Lateral margin is formed by sartorius* - The **sartorius muscle** forms the lateral boundary of the femoral triangle. - Its medial border defines one of the triangle's sides. *Medial margin is formed by adductor longus* - The **adductor longus** does form the medial boundary of the femoral triangle. - This is anatomically correct along with the inguinal ligament (superior boundary) and sartorius (lateral boundary).

Q: Which type of glial cell is derived from mesodermal origin?

Microglial cells. ***Microglial cells*** - **Microglial cells** are unique among glial cells as they originate from **mesoderm**, specifically from **monocyte/macrophage precursors** in the bone marrow [1]. - They function as the **immune cells of the central nervous system (CNS)**, scavenging for plaques, damaged neurons, and infectious agents [1]. *Macroglial cells* - This is a broad category that includes **astrocytes, oligodendrocytes, and ependymal cells**, all of which are derived from **neuroectoderm**, not mesoderm [1]. - They perform various supportive roles but are distinct in origin from microglial cells [1]. *Oligodendrocytes* - **Oligodendrocytes** are derived from **neuroectoderm** and are responsible for forming the **myelin sheath** around axons in the CNS [2]. - Myelination is crucial for rapid and efficient nerve impulse conduction. *Ependymal cells* - **Ependymal cells** are derived from **neuroectoderm** and line the **ventricles of the brain** and the **central canal of the spinal cord**. - They play a role in the production and circulation of **cerebrospinal fluid (CSF)**.

Q: Trigone of bladder is derived from?

Mesonephric duct. The trigone of the bladder is formed from the caudal ends of the **mesonephric ducts**, which are absorbed into the primitive bladder wall [1]. This mesenchymal origin explains why the trigone has a smooth lining [1] and is less prone to infection compared to the rest of the bladder. *Paramesonephric duct* - The **paramesonephric ducts** (Müllerian ducts) are involved in forming the female reproductive organs, specifically the fallopian tubes, uterus [2], and upper vagina. - They do not contribute to the formation of the urinary bladder or its trigone. *Absorbed anal membrane* - The **anal membrane** separates the endoderm-derived hindgut from the ectoderm-derived anal pit. - Its absorption is relevant to the development of the anus, not the urinary bladder. *Mullerian duct* - The **Müllerian ducts** are synonymous with the paramesonephric ducts and are primarily involved in the development of the female reproductive tract [2]. - They play no role in the development of the urinary bladder or its trigone.

Q: Sertoli cells are derived from -

Coelomic epithelium. Sertoli cells are derived from the **coelomic epithelium** (surface epithelium) of the urogenital ridge during gonadal development. - The coelomic epithelium proliferates to form the **primitive sex cords** (medullary cords in males), and cells within these cords differentiate into Sertoli cells. - These cells are essential for **spermatogenesis**, providing structural support and nutrition to developing germ cells, and producing **anti-Müllerian hormone (AMH)** which causes regression of Müllerian ducts in male development [1]. *Germinal epithelium* - This is an **outdated term** previously used for the surface epithelium of the gonad, based on the misconception that it gave rise to germ cells. - Modern embryology uses the term **coelomic epithelium** or surface epithelium instead. - While historically used, this terminology is no longer preferred in current medical literature. *Genital swelling* - **Genital swellings** (labioscrotal swellings) are external mesodermal structures that develop into the **scrotum** in males or **labia majora** in females. - These are external genitalia components and are not the source of internal testicular cells like Sertoli cells. *Primordial germ cells* - **Primordial germ cells (PGCs)** originate from the epiblast, migrate via the hindgut to the developing gonads, and differentiate into **spermatogonia** (males) or **oogonia** (females) [1]. - They form the **germ cell lineage** (gametes), not somatic support cells like Sertoli cells, which are of coelomic epithelial origin.

Q: Spleniculi are most commonly found in which of the following locations?

Hilum of the spleen. No relevant citations could be added to the explanation as the provided text passages did not contain information regarding spleniculi (accessory spleens), their location, or their embryology. ***Hilum of the spleen*** - **Spleniculi** (accessory spleens) are most commonly found at the **hilum of the spleen**, accounting for approximately **75% of cases**. - During **embryonic development**, the spleen forms from mesenchymal tissue in the dorsal mesogastrium, and small fragments of splenic tissue can separate and persist as accessory spleens. - The **splenic hilum** is the most frequent location due to the close proximity during development, followed by the gastrosplenic ligament, tail of pancreas, and greater omentum. - Accessory spleens are found in **10-30% of the population** and are clinically significant in conditions requiring complete splenectomy (e.g., ITP, hereditary spherocytosis). *Colon* - The colon is part of the **gastrointestinal tract** with a completely different embryological origin (endodermal). - Splenic tissue development occurs in the **dorsal mesogastrium** (mesodermal origin), making the colon an anatomically and embryologically implausible location for spleniculi. *Liver* - The liver develops from the **ventral foregut endoderm** and is anatomically distant from the spleen's developmental region. - **Splenosis** (traumatic implantation) could theoretically occur, but congenital spleniculi in the liver are exceptionally rare and not a recognized common location. *Lungs* - The lungs are part of the **respiratory system**, developing from the foregut endoderm in the thoracic cavity. - There is no embryological connection between lung and splenic tissue development, making this an impossible location for congenital accessory spleens.

Q: Which of the following structures does NOT pass through Calot's triangle?

Portal vein. ***Portal vein*** - The **portal vein** is located within the **porta hepatis** and does not pass through Calot's triangle, making it the correct answer to this question. - It carries venous blood from the **gastrointestinal tract** and **spleen** to the liver and is positioned medial and posterior to the structures within Calot's triangle. *Right hepatic artery* - The **right hepatic artery** is a key structure that passes through Calot's triangle and forms one of its boundaries. - It typically gives rise to the **cystic artery** within or near the triangle, making it an important anatomical landmark during **cholecystectomy**. *Lymph node of Lund* - The **lymph node of Lund** (cystic lymph node) is consistently found within Calot's triangle and serves as an important landmark. - Its presence helps surgeons identify the **boundaries of the triangle** and assess for inflammation or malignancy related to the gallbladder. *Cystic artery* - The **cystic artery** is a consistent structure within Calot's triangle, typically arising from the **right hepatic artery**. - It is routinely **ligated during cholecystectomy** and is one of the key structures surgeons must identify within the triangle.

Q: What structure passes through the quadrangular space?

Axillary nerve. Axillary nerve - The axillary nerve and the posterior circumflex humeral artery are the primary structures that pass through the quadrangular space. - Compression or injury within this space can lead to deficits in the axillary nerve's distribution, affecting the deltoid and teres minor muscles. *Radial nerve* - The radial nerve passes through the triangular interval, not the quadrangular space. - It supplies the triceps muscle and all muscles in the posterior compartment of the forearm. *Median nerve* - The median nerve travels through the cubital fossa and then down the anterior forearm, supplying most of the forearm flexors and some hand muscles. - It does not pass through any of the posterior axillary spaces. *Brachial Artery* - The brachial artery is the main arterial supply to the arm and runs anteriorly in the arm, deep to the biceps brachii muscle. - It does not pass through the quadrangular space; rather, the posterior circumflex humeral artery (a branch of the axillary artery) traverses this space.

Question 1

Which artery passes through the anatomical snuffbox?

Accepted Answer

Radial artery

Answer

Brachial artery

Answer

Ulnar artery

Answer

Interosseus artery

Question 2

Which is the largest nerve that exits the pelvis through the greater sciatic foramen?

Accepted Answer

Sciatic nerve

Answer

Superior gluteal artery

Answer

Inferior gluteal artery

Answer

Piriformis muscle

Question 3

Inversion and eversion of foot occurs at which joint

Accepted Answer

Subtalar

Answer

Ankle

Answer

Tarso-metatarsal

Answer

None of the options

Question 4

Which of the following statements about the femoral triangle is NOT true?

Accepted Answer

Floor is formed by adductor longus

Answer

Contains the femoral vessels

Answer

Lateral margin is formed by sartorius

Answer

Medial margin is formed by adductor longus

Question 5

Which type of glial cell is derived from mesodermal origin?

Accepted Answer

Microglial cells

Answer

Macroglial cells

Answer

Oligodendrocytes

Answer

Ependymal cells

Question 6

Trigone of bladder is derived from?

Accepted Answer

Mesonephric duct

Answer

Paramesonephric duct

Answer

Absorbed anal membrane

Answer

Mullerian duct

Question 7

Sertoli cells are derived from -

Accepted Answer

Coelomic epithelium

Answer

Genital swelling

Answer

Primordial germ cells

Answer

Germinal epithelium

Question 8

Spleniculi are most commonly found in which of the following locations?

Accepted Answer

Hilum of the spleen

Answer

Colon

Answer

Liver

Answer

Lungs

Question 9

Which of the following structures does NOT pass through Calot's triangle?

Accepted Answer

Portal vein

Answer

Right hepatic artery

Answer

Lymph node of Lund

Answer

Cystic artery

Question 10

What structure passes through the quadrangular space?

Accepted Answer

Axillary nerve

Answer

Radial nerve

Answer

Median nerve

Answer

Brachial Artery

NEET-PG 2015 — Anatomy