NEET-PG 2015 - Anatomy Practice Questions

Q: Which of the following is a derivative of paramesonephric duct in males ?

Prostatic utricle. ***Prostatic utricle*** - The **prostatic utricle** is a blind-ending pouch located in the prostatic urethra. - It represents a **rudimentary derivative of the paramesonephric (Müllerian) duct** in males, which normally regresses due to the presence of Müllerian-inhibiting substance (MIS). *Trigone of bladder* - The trigone of the bladder is derived from the caudal ends of the **mesonephric ducts** (Wolffian ducts), not the paramesonephric ducts. - It forms through the incorporation of these ducts into the posterior wall of the bladder. *Paraphoron* - The **paraphoron** is a vestigial structure found in females, representing remnants of the caudal parts of the **epoophoron tubules**. - These are derived from the **mesonephric tubules**, not the paramesonephric ducts, and are not found in males. *Gartner's duct* - **Gartner's duct** is a remnant of the **mesonephric (Wolffian) duct** in females, typically running along the lateral wall of the vagina or uterus. - It is not found in males and is derived from a different embryonic structure than the paramesonephric duct.

Q: Which of the following statements about the atrioventricular groove is true?

Also called coronary sulcus. ***Also called coronary sulcus*** - The **atrioventricular groove** is a critical anatomical landmark that separates the atria from the ventricles on the external surface of the heart. - This anatomical division is consistently referred to as the **coronary sulcus**, which encircles the entire heart. *Contains left anterior descending coronary artery* - The **left anterior descending (LAD) coronary artery**, also known as the anterior interventricular artery, lies within the **interventricular groove** (or sulcus), not the atrioventricular groove. - The interventricular groove separates the left and right ventricles, distinct from the atrioventricular separation. *Contains left coronary artery* - The **left coronary artery (LCA)** is a short main trunk that almost immediately divides into the **left anterior descending** (LAD) and **circumflex arteries** [1]. - While the **circumflex artery** (a branch of the LCA) runs in the left part of the atrioventricular groove, the main left coronary artery itself is too short to be considered within the groove [1]. *Contains posterior descending artery* - The **posterior descending artery (PDA)**, also known as the posterior interventricular artery, lies within the **posterior interventricular groove**, separating the ventricles posteriorly. - The PDA is a branch of either the right coronary artery (in most people) or the circumflex artery, but it follows the interventricular septum, not the atrioventricular border.

Q: Which nucleus is not seen in floor of the 4th ventricle -

Facial nucleus. Facial nucleus - The facial nucleus is located in the pontine tegmentum, anterior and ventrolateral to the abducens nucleus, and its fibers loop around the abducens nucleus forming the facial colliculus within the floor of the fourth ventricle, but the nucleus itself is not directly in the floor. - The nucleus's motor neurons originate deeper within the brainstem, not superficially in the floor. Abducens nucleus - The abducens nucleus is directly located in the floor of the fourth ventricle, beneath the facial colliculus. - Its neurons are responsible for innervating the lateral rectus muscle of the eye. Dorsal vagal nucleus - The dorsal vagal nucleus is situated in the floor of the fourth ventricle in the medulla, specifically in the vagal trigone. - It is responsible for the parasympathetic innervation of organs below the neck. Hypoglossal nucleus - The hypoglossal nucleus is located in the floor of the fourth ventricle, forming the hypoglossal trigone in the medulla. - It contains motor neurons that innervate the intrinsic and extrinsic muscles of the tongue.

Q: Floor of Petit triangle is formed by?

Internal oblique muscle. ***Internal oblique muscle*** - The **Petit triangle** (lumbar triangle) is a landmark defined by the **latissimus dorsi posteriorly**, the **external oblique anteriorly**, and the **iliac crest inferiorly**. - Its **floor** is consistently formed by the **internal oblique muscle**, which lies deep to the external oblique [1]. *Sacrospinalis muscle* - The **sacrospinalis muscle** (erector spinae) is part of the deep back muscles, located medial to the Petit triangle. - It forms part of the **vertebral column's musculature** and is not directly associated with the floor of the Petit triangle. *Rectus abdominis muscle* - The **rectus abdominis muscle** is located medially in the anterior abdominal wall [1]. - It is distinct from the lateral abdominal wall muscles that form the boundaries and floor of the Petit triangle. *Fascia Transversalis layer* - The **fascia transversalis** is a deeper fascial layer lining the abdominal wall. - While it's deep to the internal oblique, the **muscle itself** forms the immediate anatomical floor of the Petit triangle.

Q: Fibrous stroma of liver is derived from -

Mesoderm from the septum transversum. ***Mesoderm from the septum transversum*** - The **fibrous stroma of the liver**, which provides its structural framework, develops from the **mesoderm** of the **septum transversum** [1]. - The septum transversum is a thick mass of mesoderm that contributes to the formation of the **diaphragm** and the connective tissue elements of the liver [1]. *Endoderm from the foregut* - While the **parenchymal cells (hepatocytes)** of the liver are derived from the **endoderm of the foregut**, this tissue forms the functional units, not the fibrous supporting stroma. - The endoderm forms the glandular tissue, while the mesoderm forms the connective tissue [1]. *Endoderm from the midgut* - The midgut endoderm gives rise to structures like the **small intestine**, cecum, appendix, ascending colon, and part of the transverse colon, but not the liver's stroma [2]. - Its primary role is in forming the epithelial lining of these digestive organs. *Endoderm from the hindgut* - The hindgut endoderm develops into the distal third of the transverse colon, descending colon, sigmoid colon, rectum, and superior part of the anal canal, - It plays no role in the development of the liver's fibrous stroma.

Q: Which artery supplies the anterior part of the interventricular septum?

Left anterior descending artery (LAD). ***Left anterior descending artery (LAD)*** - The **LAD** is a branch of the **left main coronary artery** and is also known as the "widowmaker" due to its critical supply to a large portion of the left ventricle and the interventricular septum [1]. - It gives rise to **septal branches** that typically supply the anterior two-thirds of the interventricular septum [1]. *Right coronary artery* - The **right coronary artery (RCA)** primarily supplies the **right ventricle**, the right atrium, the SA node (in 60% of people), and the AV node (in 90% of people). - It typically supplies the **inferior wall** of the left ventricle and the posterior one-third of the interventricular septum [1]. *Posterior descending coronary artery* - The **posterior descending artery (PDA)** arises from the **RCA** (in approximately 85% of individuals, known as right dominance) or less commonly from the circumflex artery (in left dominance) [1]. - It supplies the **posterior one-third** of the interventricular septum and typically the inferior wall of the left ventricle [1]. *None of the options* - This option is incorrect because the **LAD** clearly and predominantly supplies the anterior part of the interventricular septum.

Q: What structure is primarily responsible for forming the anorectal angle?

Puborectalis muscle. ***Puborectalis muscle*** - The **puborectalis muscle** is a U-shaped sling of skeletal muscle that originates from the pubis and loops around the posterior aspect of the anorectal junction, pulling the rectum anteriorly [1]. - This anterior traction creates the characteristic **anorectal angle**, which is crucial for maintaining fecal continence at rest [1], [2]. *Circular smooth muscle layer* - The **circular smooth muscle layer** is part of the involuntary muscular wall of the rectum and anal canal. - While it contributes to internal anal sphincter function, its primary role is not in forming the acute anorectal angle [2]. *Longitudinal smooth muscle layer* - The **longitudinal smooth muscle layer** runs along the entire gastrointestinal tract, including the rectum, and contributes to the overall structure and peristalsis. - It does not directly form the anorectal angle; that function is specific to the puborectalis muscle. *Internal anal sphincter muscle* - The **internal anal sphincter** is an involuntary smooth muscle thickening of the circular muscle layer, primarily responsible for resting anal tone [2]. - It plays a vital role in continence but does not contribute to the creation of the anorectal angle [2].

Q: Superficial inguinal ring is a defect in the:

External oblique aponeurosis. ***External oblique aponeurosis*** - The **superficial inguinal ring** is a triangular opening in the **aponeurosis of the external oblique muscle** [1]. - It allows passage of the **spermatic cord** in males and the **round ligament of the uterus** in females. *Transverse abdominis aponeurosis* - The **transverse abdominis aponeurosis** contributes to the posterior wall of the **inguinal canal**, but not the superficial inguinal ring itself [2]. - The deepest abdominal muscle, its aponeurosis forms the **conjoint tendon** with the internal oblique aponeurosis. *Internal oblique muscle* - The **internal oblique muscle** forms the arching roof and part of the anterior wall of the **inguinal canal** [2]. - Its aponeurosis contributes to the **conjoint tendon** and the falx inguinalis. *Internal oblique aponeurosis* - The **internal oblique aponeurosis** is part of the anterior wall and forms the conjoint tendon with the transverse abdominis aponeurosis [2]. - This aponeurosis does not form the superficial inguinal ring; instead, it is found deeper to the external oblique aponeurosis.

Q: Inferior epigastric artery forms the boundary of?

Hesselbach's triangle. ***Hesselbach's triangle*** - The **inferior epigastric artery** forms the superolateral border of Hesselbach's triangle [1]. - This triangle is clinically significant as it is a common site for **direct inguinal hernias** due to its relative weakness [1]. *Femoral triangle* - The femoral triangle is bounded by the **inguinal ligament superiorly**, the **sartorius muscle laterally**, and the **adductor longus muscle medially**. - It contains the **femoral nerve**, artery, and vein. *Adductor canal* - The adductor canal is an intermuscular tunnel located in the **thigh**, containing the **femoral artery and vein** and the **saphenous nerve**. - Its boundaries are the **vastus medialis**, adductor longus/magnus, and sartorius muscles. *Popliteal triangle* - This term is not a standard anatomical triangle. The correct term is the **popliteal fossa**, which is a diamond-shaped space behind the knee joint. - The popliteal fossa contains structures such as the **popliteal artery and vein**, tibial nerve, and common fibular nerve.

Question 1

Which of the following is a derivative of paramesonephric duct in males ?

Accepted Answer

Prostatic utricle

Answer

Trigone of bladder

Answer

Paraphoron

Answer

Gartner's duct

Question 2

Which of the following statements about the atrioventricular groove is true?

Accepted Answer

Also called coronary sulcus

Answer

Contains left anterior descending coronary artery

Answer

Contains posterior descending artery

Answer

Contains left coronary artery

Question 3

Which nucleus is not seen in floor of the 4th ventricle -

Accepted Answer

Facial nucleus

Answer

Dorsal vagal nucleus

Answer

Hypoglossal nucleus

Answer

Abducens nucleus

Question 4

Hilton's law primarily relates to which of the following?

Accepted Answer

Nerve supply of joints, muscles moving them, and overlying skin

Answer

Nerve innervation only

Answer

Blood supply to joints

Answer

None of the above

Question 5

Floor of Petit triangle is formed by?

Accepted Answer

Internal oblique muscle

Answer

Sacrospinalis muscle

Answer

Rectus abdominis muscle

Answer

Fascia Transversalis layer

Question 6

Fibrous stroma of liver is derived from -

Accepted Answer

Mesoderm from the septum transversum

Answer

Endoderm from the foregut

Answer

Endoderm from the midgut

Answer

Endoderm from the hindgut

Question 7

Which artery supplies the anterior part of the interventricular septum?

Accepted Answer

Left anterior descending artery (LAD)

Answer

Right coronary artery

Answer

Posterior descending coronary artery

Answer

None of the options

Question 8

What structure is primarily responsible for forming the anorectal angle?

Accepted Answer

Puborectalis muscle

Answer

Circular smooth muscle layer

Answer

Longitudinal smooth muscle layer

Answer

Internal anal sphincter muscle

Question 9

Superficial inguinal ring is a defect in the:

Accepted Answer

External oblique aponeurosis

Answer

Internal oblique muscle

Answer

Transverse abdominis aponeurosis

Answer

Internal oblique aponeurosis

Question 10

Inferior epigastric artery forms the boundary of?

Accepted Answer

Hesselbach's triangle

Answer

Femoral triangle

Answer

Adductor canal

Answer

Popliteal triangle

NEET-PG 2015 — Anatomy