Anatomy
9 questionsWhich of the following is not formed by the external oblique muscle?
Inferior epigastric artery forms the boundary of?
Which of the following is NOT a boundary of the foramen of Winslow?
What structure is primarily responsible for forming the anorectal angle?
The uterine artery is a branch of which of the following?
Tail of pancreas develops from -
Haustrations are present in -
Which of the following provides the MOST COMPLETE description of muscles attached to the perineal body?
Distance of cricopharynx from incisor teeth
NEET-PG 2015 - Anatomy NEET-PG Practice Questions and MCQs
Question 91: Which of the following is not formed by the external oblique muscle?
- A. Inguinal ligament
- B. Lacunar ligament
- C. Pectineal ligament
- D. Conjoint tendon (Correct Answer)
Explanation: ***Conjoint tendon*** - The **conjoint tendon** is formed by the conjoined aponeuroses of the **internal oblique** and **transversus abdominis muscles**, not the external oblique [1]. - It provides posterior wall reinforcement to the inguinal canal. - This is the structure that is definitively **NOT formed by the external oblique muscle**. *Lacunar ligament* - The **lacunar ligament** (Gimbernat's ligament) is a triangular fascial band formed by the medial reflection of the **inguinal ligament**. - It is derived from the **external oblique aponeurosis** and forms the medial boundary of the femoral ring. *Pectineal ligament* - The **pectineal ligament** (Cooper's ligament) is a thickening of the periosteum along the pecten pubis (pectineal line) [3]. - While it is continuous with the lacunar ligament, it is not directly formed by the external oblique muscle itself, but rather represents a separate periosteal structure. - For the purposes of this question, the conjoint tendon is the most appropriate answer as it has no contribution from the external oblique. *Inguinal ligament* - The **inguinal ligament** (Poupart's ligament) is formed by the inferomedial border of the **external oblique aponeurosis**, folding back on itself [2]. - It spans between the **anterior superior iliac spine** and the **pubic tubercle**.
Question 92: Inferior epigastric artery forms the boundary of?
- A. Femoral triangle
- B. Hesselbach's triangle (Correct Answer)
- C. Adductor canal
- D. Popliteal triangle
Explanation: ***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 93: Which of the following is NOT a boundary of the foramen of Winslow?
- A. Inferior vena cava
- B. Free border of lesser omentum
- C. 4th part of Duodenum (Correct Answer)
- D. Caudate lobe of liver
Explanation: 4th part of Duodenum[1] - The foramen of Winslow (epiploic foramen) is an opening that connects the greater sac to the lesser sac of the peritoneum. The 4th part of the duodenum is not a boundary of this foramen. - The 4th part of the duodenum is located at the duodenojejunal junction on the left side of the abdomen, far from the foramen of Winslow. - Note: The 1st part of the duodenum (D1) forms the inferior boundary of the foramen of Winslow, along with the hepatic artery. Inferior vena cava[1] - The inferior vena cava (IVC) forms the posterior boundary of the foramen of Winslow. - It lies behind the peritoneum that forms the posterior wall of the lesser sac at this point. Free border of lesser omentum[1] - The free border of the lesser omentum (hepatoduodenal ligament) forms the anterior boundary of the foramen of Winslow. - This ligament contains the portal triad (hepatic artery proper, portal vein, and common bile duct). Caudate lobe of liver[1] - The caudate lobe of the liver forms the superior boundary of the foramen of Winslow.[1] - It lies above the opening, contributing to its roof.
Question 94: 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 95: 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 96: 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 97: 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 98: Which of the following provides the MOST COMPLETE description of muscles attached to the perineal body?
- A. Deep transverse perineal
- B. Ischiocavernosum
- C. Two unpaired : (i) External anal sphincter, (ii) Fibres of longitudinal muscle coat of anal canal.
- D. Four paired muscles including bulbospongiosus, superficial transverse perineal, deep transverse perineal, and levator ani. In females, sphincter urethrovaginalis is also attached. (Correct Answer)
Explanation: Four paired muscles including bulbospongiosus, superficial transverse perineal, deep transverse perineal, and levator ani. In females, sphincter urethrovaginalis is also attached. [1] - The **perineal body** (or central tendon of the perineum) is a fibromuscular mass located in the midline of the perineum, serving as an important point of attachment for multiple muscles essential for pelvic floor integrity. - This option correctly identifies **four paired muscles** (bulbospongiosus, superficial transverse perineal, deep transverse perineal, and levator ani) and additionally mentions the **sphincter urethrovaginalis** in females, providing the most thorough description. [1] *Ischiocavernosus* - The **ischiocavernosus** muscle surrounds the crus of the penis or clitoris and attaches to the ischial tuberosity and pubic ramus. - While it contributes to perineal function, it does **not** directly attach to the perineal body, making this option incorrect. *Deep transverse perineal* - The **deep transverse perineal** muscle does attach to the perineal body and is part of the urogenital diaphragm. [1] - However, it is only one of several muscles, making this an incomplete description compared to the correct answer. *Two unpaired: (i) External anal sphincter, (ii) Fibres of longitudinal muscle coat of anal canal* - The **external anal sphincter** does indeed have fibers that connect to the perineal body, and the longitudinal muscle coat of the anal canal also contributes. [1] - However, this option *only* lists two unpaired structures and omits major paired muscles (bulbospongiosus, superficial transverse perineal, deep transverse perineal, and levator ani), making it an incomplete description of all attachments.
Question 99: Distance of cricopharynx from incisor teeth
- A. 22 cm
- B. 27 cm
- C. 40 cm
- D. Approximately 15 cm (Correct Answer)
Explanation: ***Approximately 15 cm*** - The **cricopharynx** (upper esophageal sphincter at C6 level), which is the narrowest part of the pharynx, is typically located about **15 cm** from the incisor teeth in adults. - This anatomical landmark is crucial in procedures such as **endoscopy**, **intubation**, and **nasogastric tube insertion** to avoid injury. *22 cm* - This distance corresponds to the level of the **aortic arch** (second physiological narrowing of the esophagus). - This is where the aorta crosses anterior to the esophagus, creating the broncho-aortic constriction. *27 cm* - A distance of 27 cm from the incisor teeth corresponds to the level where the **left main bronchus** crosses the esophagus (third physiological narrowing). - This is well beyond the location of the **cricopharynx** and represents the mid-esophageal region. *40 cm* - This measurement represents the approximate total length of the **esophagus**, reaching the **gastroesophageal junction** at the level of the **diaphragmatic hiatus** (cardia of the stomach). - The **cricopharynx** is at the very beginning of this path, much closer to the incisors.
Internal Medicine
1 questionsIn which portion of the esophagus do esophageal varices primarily occur?
NEET-PG 2015 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 91: In which portion of the esophagus do esophageal varices primarily occur?
- A. All sites
- B. Upper
- C. Lower (Correct Answer)
- D. Middle
Explanation: **Lower** - Esophageal varices are most commonly found in the **distal (lower) third of the esophagus** [1] because this is where the portal venous system (short gastric and left gastric veins) anastomoses with the systemic venous system (white esophageal veins draining into the azygous system) [1]. - Increased portal pressure (e.g., in **portal hypertension** due to liver cirrhosis) causes blood to back up into these collateral vessels, leading to their dilation and formation of varices, particularly prominent in the lower esophagus [1]. *Upper* - While some collateral circulation exists throughout the esophagus, varices are not predominantly found in the upper portion as the primary portosystemic anastomoses responsible for variceal formation are more distal. - Varices in the upper esophagus are less common and typically less clinically significant in terms of bleeding risk. *Middle* - The middle portion of the esophagus has some venous drainage, but it is not the primary site for the significant portosystemic collaterals that lead to the formation of large, high-risk varices. - Varices can extend into the middle esophagus, but their origin and highest concentration are usually in the lower third. *All sites* - While varices can technically be found at various points along the esophagus, stating "all sites" is inaccurate because they have a **marked predilection for the lower third** due to specific anatomical venous connections [1]. - The risk of rupture and bleeding is also highest in the larger varices found in the lower esophagus [1].