Anatomy
10 questionsSuperior gluteal nerve does not supply?
Haustrations are present in -
Which structure may persist as a remnant of the Müllerian duct in males?
Superior vena cava develops from?
Tail of pancreas develops from -
Prolactin secreting gland develops from -
The uterine artery is a branch of which of the following?
Which of the following muscles is not supplied by the femoral nerve?
What structure is primarily responsible for forming the anorectal angle?
Which of the following statements about the limbus fossa ovalis is false?
NEET-PG 2015 - Anatomy NEET-PG Practice Questions and MCQs
Question 141: Superior gluteal nerve does not supply?
- A. Tensor fasciae latae
- B. Gluteus medius
- C. Gluteus minimus
- D. Gluteus maximus (Correct Answer)
Explanation: ***Gluteus maximus*** - The **gluteus maximus** muscle is primarily innervated by the **inferior gluteal nerve** (L5, S1, S2), not the superior gluteal nerve. - Its main actions include **extension** and **external rotation** of the hip. *Tensor fasciae latae* - The **tensor fasciae latae** is innervated by the **superior gluteal nerve** (L4, L5, S1). - This muscle helps in **flexion**, **abduction**, and **internal rotation** of the hip. *Gluteus medius* - The **gluteus medius** muscle receives its innervation from the **superior gluteal nerve** (L4, L5, S1). - It is a primary **abductor** and **internal rotator** of the hip, crucial for pelvic stability. *Gluteus minimus* - The **gluteus minimus** is also innervated by the **superior gluteal nerve** (L4, L5, S1). - Its functions are similar to the gluteus medius, including **abduction** and **internal rotation** of the hip.
Question 142: Haustrations are present in -
- A. Duodenum
- B. Ileum
- C. Jejunum
- D. Colon (Correct Answer)
Explanation: ***Colon*** - **Haustrations** are characteristic sacculations or pouches that give the colon its segmented appearance [1]. - They are formed by the tonic contractions of the **teniae coli**, which are three distinct bands of longitudinal smooth muscle found in the muscularis externa of the colon. *Duodenum* - The duodenum is the first part of the small intestine and is characterized by **plicae circulares (circular folds)** and **villi**, not haustrations. - Its primary role is chemical digestion and initial absorption, with a smooth, folded inner surface. *Ileum* - The ileum is the final and longest part of the small intestine, featuring **Peyer's patches** (lymphoid nodules) and prominent plicae circulares [2], but lacks haustrations. - Its main function is the absorption of vitamin B12 and bile salts [2]. *Jejunum* - The jejunum is the middle section of the small intestine, known for its tall and numerous **plicae circulares** and villi, making it highly efficient for nutrient absorption. - It does not possess haustrations, which are unique to the large intestine.
Question 143: Which structure may persist as a remnant of the Müllerian duct in males?
- A. Seminal vesicle
- B. Epididymis
- C. Prostatic utricle (Correct Answer)
- D. Ureter
Explanation: ***Prostatic utricle*** - The **Müllerian ducts** (paramesonephric ducts) are primarily female reproductive structures. In males, the **anti-Müllerian hormone (AMH)** causes their regression. - The **prostatic utricle** is a small blind-ended pouch located at the prostatic urethra, representing the remnant of the fused caudal ends of the Müllerian ducts. *Seminal vesicle* - The **seminal vesicles** develop from the **mesonephric (Wolffian) ducts**, not the Müllerian ducts. - They contribute to semen production and are functional male reproductive organs, not remnants of female structures. *Epididymis* - The **epididymis** also develops from the **mesonephric (Wolffian) ducts**. - It functions in sperm maturation and storage and is part of the male reproductive tract, not a Müllerian remnant. *Ureter* - The **ureters** are conduits for urine from the kidneys to the bladder and develop from the **ureteric bud**, an outgrowth of the mesonephric duct, but are distinct from Müllerian structures. - They are part of the urinary system in both sexes and are not considered remnants of the Müllerian duct.
Question 144: Superior vena cava develops from?
- A. Right anterior cardinal vein (Correct Answer)
- B. Left anterior cardinal vein
- C. Left common cardinal vein
- D. Right subcardinal vein
Explanation: Right anterior cardinal vein - The superior vena cava (SVC) forms from the right anterior cardinal vein and the common cardinal vein. - The right anterior cardinal vein directly contributes to the upper portion of the SVC. Left anterior cardinal vein - The left anterior cardinal vein typically regresses or becomes minor tributaries like the left SVC (if persistent) or the coronary sinus. - It does not form the main superior vena cava. Left common cardinal vein - The left common cardinal vein forms the coronary sinus and an oblique vein of the left atrium. - While major vessels drain into it, it does not directly form the superior vena cava. Right subcardinal vein - The right subcardinal vein is primarily involved in the development of the inferior vena cava (IVC), particularly its renal segment. - It does not contribute to the formation of the superior vena cava.
Question 145: Tail of pancreas develops from -
- A. Hepatic diverticulum
- B. Ventral pancreatic bud
- C. Dorsal pancreatic bud (Correct Answer)
- D. All of the options
Explanation: Dorsal pancreatic bud - The dorsal pancreatic bud forms the majority of the pancreas, including the body, tail, and most of the head [1]. - It arises from the dorsal mesentery of the duodenum [1]. Hepatic diverticulum - The hepatic diverticulum gives rise to the liver, gallbladder, and bile ducts [2]. - It is separate from the pancreatic development and does not contribute to the pancreas. Ventral pancreatic bud - The ventral pancreatic bud forms only a small part of the pancreas, specifically the inferior portion of the head and the uncinate process [1]. - It rotates posteriorly with the duodenum to fuse with the dorsal bud [1]. All of the options - This option is incorrect because only the dorsal pancreatic bud forms the tail of the pancreas [1]. - The hepatic diverticulum does not contribute to pancreatic development at all, and the ventral pancreatic bud only forms the uncinate process and part of the head [1].
Question 146: Prolactin secreting gland develops from -
- A. Infundibulum
- B. Rathke's pouch (Correct Answer)
- C. Tuber cinereum
- D. 3rd ventricle
Explanation: ***Rathke's pouch*** - The **anterior pituitary gland**, which secretes prolactin [2], develops embryologically from **Rathke's pouch**. - Rathke's pouch is an **ectodermal evagination** from the roof of the primitive oral cavity (stomodeum). *Infundibulum* - The **infundibulum** is also known as the pituitary stalk, connecting the hypothalamus to the posterior pituitary [1]. - It is derived from **neuroectoderm** and forms part of the posterior pituitary, not the prolactin-secreting anterior pituitary [1]. *Tuber cinereum* - The **tuber cinereum** is a part of the **hypothalamus**. - It is involved in regulating several bodily functions but does not directly give rise to the prolactin-secreting gland. *3rd ventricle* - The **3rd ventricle** is one of the four ventricles of the brain, filled with **cerebrospinal fluid**. - It is a part of the central nervous system and is not involved in the embryological development of the pituitary gland.
Question 147: The uterine artery is a branch of which of the following?
- A. Left common iliac artery
- B. Internal iliac artery (Correct Answer)
- C. Internal pudendal artery
- D. Ovarian artery
Explanation: ***Internal iliac artery*** - The **uterine artery** is a direct branch of the **internal iliac artery**, specifically its anterior division, which supplies blood to the uterus [1]. - This artery is crucial for maintaining the vascular supply to the uterus, especially during pregnancy. *Left common iliac artery* - The **common iliac artery** bifurcates into the **internal iliac artery** and the **external iliac artery** [2]; it is not a direct source of the uterine artery. - The common iliac artery is a more proximal vessel in the arterial tree. *Internal pudendal artery* - The **internal pudendal artery** is also a branch of the **internal iliac artery**, but it primarily supplies the perineum and external genitalia, not the uterus. - It is often associated with structures such as the clitoris, labia, and structures of the anal triangle. *Ovarian artery* - The **ovarian artery** originates directly from the **abdominal aorta**, usually just below the renal arteries, and supplies the ovaries [2]. - Although it supplies the reproductive system, it is distinct from the uterine artery's origin and primary territory.
Question 148: Which of the following muscles is not supplied by the femoral nerve?
- A. Pectineus
- B. Sartorius
- C. Vastus medialis
- D. Obturator externus (Correct Answer)
Explanation: ***Obturator externus*** - The **obturator externus** muscle is primarily supplied by the **obturator nerve** (L3-L4), which arises from the lumbar plexus, not the femoral nerve. - Its main function is the **lateral rotation of the thigh** at the hip joint. *Pectineus* - The **pectineus** muscle receives dual innervation, typically from both the **femoral nerve** (L2-L4) and the obturator nerve. - It aids in **adduction**, **flexion**, and **medial rotation** of the thigh. *Sartorius* - The **sartorius** muscle is entirely supplied by the **femoral nerve** (L2-L3). - It is responsible for **flexing, abducting, and laterally rotating the thigh** at the hip, and flexing the leg at the knee. *Vastus medialis* - The **vastus medialis** is one of the four muscles forming the quadriceps femoris group, all of which are exclusively supplied by the **femoral nerve** (L2-L4). - This muscle is crucial for **extending the leg** at the knee joint.
Question 149: What structure is primarily responsible for forming the anorectal angle?
- A. Circular smooth muscle layer
- B. Longitudinal smooth muscle layer
- C. Puborectalis muscle (Correct Answer)
- D. Internal anal sphincter muscle
Explanation: ***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].
Question 150: Which of the following statements about the limbus fossa ovalis is false?
- A. Also called Annulus ovalis
- B. Derived from septum primum (Correct Answer)
- C. In right atrium
- D. Forms the rim around fossa ovalis
Explanation: ***Derived from septum primum*** - The **limbus fossa ovalis** (or annulus ovalis) is a structure in the right atrium that forms the prominent rim of the **fossa ovalis**. - It is derived from the inferior border of the **septum secundum**, not the septum primum, which primarily forms the floor of the fossa ovalis. *Forms the rim around fossa ovalis* - The **limbus fossa ovalis** is indeed the thickened, crescent-shaped border of tissue that surrounds the **fossa ovalis** in the interatrial septum. - This anatomical arrangement is a remnant of the **foramen ovale** from fetal circulation [1]. *In right atrium* - The **fossa ovalis** and its surrounding limbus are located on the septal wall of the **right atrium** [1]. - This position is crucial for its role as a key landmark in interatrial septum anatomy. *Also called Annulus ovalis* - The term **annulus ovalis** is a widely accepted synonym for the **limbus fossa ovalis**. - Both terms describe the same anatomical structure, the fibrous rim surrounding the fossa ovalis.