Anatomy
9 questionsThe structure which lies outside the femoral sheath is:
What structure is primarily responsible for forming the anorectal angle?
Which of the following is NOT a boundary of the foramen of Winslow?
Which structure is contained within the femoral canal?
Inferior epigastric artery forms the boundary of?
Which of the following is not formed by the external oblique muscle?
Which of the following statements about the femoral triangle is NOT true?
Which of the following statements about the limbus fossa ovalis is false?
Common hepatic artery is a branch of:
NEET-PG 2015 - Anatomy NEET-PG Practice Questions and MCQs
Question 131: The structure which lies outside the femoral sheath is:
- A. Genitofemoral nerve
- B. Femoral vein
- C. Femoral artery
- D. Femoral nerve (Correct Answer)
Explanation: ***Femoral nerve*** - The **femoral nerve** lies lateral to the femoral artery and is therefore situated outside the **femoral sheath**, which encloses the femoral artery, femoral vein, and lymphatic vessels [2]. - It originates from the lumbar plexus (L2-L4) and provides motor innervation to the quadriceps femoris and sensory innervation to the anterior thigh and medial leg. *Femoral artery* - The **femoral artery** is a primary content of the **femoral sheath**, occupying the most lateral compartment. - It is a continuation of the external iliac artery and is a major blood supply to the lower limb. *Femoral vein* - The **femoral vein** lies within the **femoral sheath**, positioned medial to the femoral artery. - It is the primary vein responsible for draining blood from the lower limb and eventually becomes the external iliac vein. *Genitofemoral nerve* - The **genitofemoral nerve** typically emerges on the anterior surface of the psoas major muscle and then usually divides into genital and femoral branches [1]. - While its femoral branch supplies sensory innervation to the skin over the femoral triangle, it does not course within the femoral sheath itself but rather anterior to it or outside its immediate vicinity [1].
Question 132: 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 133: 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 134: Which structure is contained within the femoral canal?
- A. Deep inguinal lymph node (Correct Answer)
- B. Loose areolar tissue and fat
- C. Lymphatic vessels
- D. Femoral vein
Explanation: ***Deep inguinal lymph node*** - The **femoral canal** contains several structures: a **lymph node (of Cloquet or Rosenmüller)**, **lymphatic vessels**, and **loose areolar tissue**. [1] - Among these contents, the **deep inguinal lymph node** (also called the lymph node of Cloquet or Rosenmüller) is the **most clinically significant and specifically named structure**. - This lymph node is an important anatomical landmark, serving as a sentinel node that drains lymph from the lower limb, external genitalia, and perineum. - **Clinically**, it is the structure most commonly referenced when discussing femoral canal contents, particularly in the context of femoral hernias and lymphatic drainage patterns. [1] *Loose areolar tissue and fat* - While **loose areolar tissue and fat** are indeed present within the femoral canal, they are **supporting contents** rather than specifically named anatomical structures. [1] - These tissues fill the space and allow for expansion of adjacent vessels (femoral artery and vein), but they are not the primary structure of anatomical or clinical significance. - When asked about "the structure" in the femoral canal, the named lymph node is the more specific answer. *Lymphatic vessels* - **Lymphatic vessels** do traverse the femoral canal, but they are **conduits** rather than a discrete, named structure. [1] - These vessels drain lymph towards the deep inguinal lymph node (of Cloquet) located within the same canal. - The specifically named lymph node is the more definitive anatomical answer than the unnamed vessels passing through. *Femoral vein* - The **femoral vein** is located in the **intermediate compartment of the femoral sheath**, NOT within the femoral canal. - The femoral sheath has three compartments: lateral (femoral artery), intermediate (femoral vein), and medial (femoral canal). - The femoral vein lies lateral to the femoral canal, making this option clearly incorrect.
Question 135: 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 136: 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 137: Which of the following statements about the femoral triangle is NOT true?
- A. Contains the femoral vessels
- B. Floor is formed by adductor longus (Correct Answer)
- C. Lateral margin is formed by sartorius
- D. Medial margin is formed by adductor longus
Explanation: ***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).
Question 138: 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.
Question 139: Common hepatic artery is a branch of:
- A. Splenic artery
- B. Superior mesenteric artery
- C. Inferior mesenteric artery
- D. Coeliac trunk (Correct Answer)
Explanation: ***Coeliac trunk*** - The **common hepatic artery** is one of the three main branches arising from the **coeliac trunk**, which is the first major anterior branch of the abdominal aorta [1]. - It typically supplies the **liver**, gallbladder, pylorus of the stomach, and part of the duodenum through its various branches [1]. *Splenic artery* - The **splenic artery** is another major branch of the coeliac trunk, primarily supplying the **spleen**, and also gives off branches to the stomach and pancreas [1]. - It does not directly give rise to the common hepatic artery. *Superior mesenteric artery* - The **superior mesenteric artery (SMA)** originates just inferior to the coeliac trunk from the abdominal aorta and supplies structures of the **midgut**, including the small intestine, and parts of the large intestine. - It is not a direct source of the common hepatic artery. *Inferior mesenteric artery* - The **inferior mesenteric artery (IMA)** arises from the abdominal aorta further inferior to the SMA and supplies the **hindgut**, including the distal transverse colon to the superior part of the rectum. - It is anatomically distinct and separate from the arterial supply to the foregut-derived organs supplied by the common hepatic artery.
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 131: 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].