NEET-PG 2012 Practice Questions

Q: Azygos vein drains into:

Superior vena cava. Wait, what? Azygos vein drains into: ***Superior vena cava*** - The **azygos vein** ascends along the right side of the vertebral column and typically arches over the root of the right lung before draining into the **superior vena cava (SVC)**. - This anatomical arrangement allows the azygos system to collect venous blood from the posterior thoracic and abdominal walls, as well as the bronchi and esophagus, ultimately returning it to the systemic circulation via the SVC [1]. *Left brachiocephalic vein* - The **left brachiocephalic vein** drains blood from the upper left limb and left side of the head and neck. - It merges with the right brachiocephalic vein to form the SVC; the azygos vein does not directly drain into it. *Inferior vena cava* - The **inferior vena cava (IVC)** collects deoxygenated blood from the lower body. - The azygos system primarily drains structures above the diaphragm, distinct from the IVC's drainage area. *Right brachiocephalic vein* - The **right brachiocephalic vein** drains blood from the upper right limb and right side of the head and neck. - While it contributes to the formation of the SVC, the azygos vein's direct connection is to the SVC itself, not the right brachiocephalic vein.

Q: Where is the neurovascular plane located in the anterior abdominal wall?

Between internal oblique and transversus abdominis. ***Between internal oblique and transversus abdominis*** - This space, often referred to as the **transversus abdominis plane (TAP)**, contains the major neurovascular bundles supplying the anterior abdominal wall [1]. - The nerves here are the lower **thoracic (T7-T11)** and **iliohypogastric/ilioinguinal (L1) nerves**, along with accompanying blood vessels [1]. *Between external oblique and internal oblique* - This fascial plane primarily houses some superficial nerves and vessels but not the main neurovascular supply to the abdominal wall muscles. - The major neurovascular bundles for deeper muscle layers and skin are located deeper to the **internal oblique** [1]. *Below transversus abdominis* - Below the **transversus abdominis** muscle lies the **transversalis fascia**, an extraperitoneal fat layer, and then the **peritoneum**. - This deeper region primarily contains retroperitoneal structures and organs, not the main neurovascular plane for the abdominal wall. *Above external oblique* - The layer above the **external oblique** muscle is primarily subcutaneous tissue and skin. - While superficial nerves and vessels are present here, this is not the main neurovascular plane that supplies the muscles of the anterior abdominal wall.

Q: Ovarian fossa is formed by all except?

Round ligament of ovary. ***Round ligament of ovary*** - The **round ligament of ovary** (ovarian ligament) connects the ovary to the lateral wall of the uterus and does NOT form any boundary of the ovarian fossa [1]. - It lies medial to the ovary and is not involved in forming the depression of the ovarian fossa [1]. - This ligament anchors the ovary but is separate from the peritoneal boundaries defining the fossa [1]. *Obliterated umbilical artery* - The **obliterated umbilical artery** (medial umbilical ligament) forms the **anterior boundary** of the ovarian fossa [2]. - This is a key anatomical landmark running along the lateral pelvic wall anterior to the ovary [2]. *Internal iliac artery* - The **internal iliac artery** forms the **posterior boundary** of the ovarian fossa [2]. - It lies on the lateral pelvic wall, deep and posterior to the ovarian fossa [2]. - This is one of the main structures defining the fossa's posterior limit [2]. *Ureter* - The **ureter** runs along the lateral pelvic wall and forms part of the **posterior/floor boundary** of the ovarian fossa [2]. - It passes posteroinferior to the ovary, contributing to the fossa's posterior limits [2].

Q: Which of the following is not a branch of the inferior mesenteric artery?

Middle rectal. ***Middle rectal artery*** - The **middle rectal artery** [2] is typically a branch of the **internal iliac artery** [2], supplying the middle part of the rectum. - It is not a direct branch of the inferior mesenteric artery. *Left colic artery* - The left colic artery is a direct branch of the **inferior mesenteric artery** [1], supplying the distal transverse colon and descending colon. - It forms an important anastomosis with the middle colic artery [1]. *Superior rectal artery* - The **superior rectal artery** is the terminal branch of the **inferior mesenteric artery**, supplying the upper rectum. - This artery provides the primary arterial supply to the proximal large intestine structures. *Sigmoidal artery* - The **sigmoidal arteries** are typically 2-4 branches arising from the **inferior mesenteric artery**, supplying the sigmoid colon. - These arteries anastomose with branches of the superior rectal and left colic arteries.

Q: What does Chamberlain's line refer to in anatomical terms?

Palate to foramen magnum. ***Palate to foramen magnum*** - **Chamberlain's line** is a measurement used in radiology to assess for **basilar invagination** or impression. - It extends from the **posterior margin of the hard palate** to the **posterior lip of the foramen magnum**. *Palate to occiput* - This description is too general and does not precisely define Chamberlain's line, which specifically uses the **posterior lip of the foramen magnum** as its posterior anchor point. - While the foramen magnum is within the occipital bone, "occiput" can refer to a broader area. *Palate to temporal* - The **temporal bone** is not part of the anatomical landmarks used for Chamberlain's line. - This line is focused on structures in the midline skull base. *Palate to parietal* - The **parietal bone** is located superiorly and laterally to the structures involved in Chamberlain's line. - It is not used as a landmark for this specific measurement.

Q: In the context of cell membrane composition, what is the typical weight ratio of protein to lipid?

1 : 1. ***1 : 1*** - The **typical weight ratio of protein to lipid** in most cell membranes is approximately **1:1** (equal by weight). - While the **number of lipid molecules** far exceeds the number of protein molecules, proteins are much larger and heavier, resulting in roughly equal weight contributions. - This **1:1 ratio represents an average** for typical plasma membranes, though it can vary significantly depending on membrane type and function. *1 : 2* - This protein:lipid ratio would indicate **lipids contribute twice as much by weight** as proteins. - This is characteristic of **myelin membranes**, which are specialized for insulation and have exceptionally high lipid content. - However, this is **not typical** of most cell membranes. *2 : 1* - This ratio would suggest **proteins contribute twice as much by weight** as lipids. - While some protein-rich membranes exist, this is **higher than the average** for typical cell membranes. - The typical ratio is closer to 1:1 rather than being protein-dominant at 2:1. *4 : 1* - A 4:1 protein:lipid ratio represents an **extremely protein-rich membrane**. - This is characteristic of the **inner mitochondrial membrane**, which is packed with electron transport chain proteins. - This is a **specialized membrane**, not representative of typical cell membranes.

Q: Osmolarity is defined as?

Number of osmoles per litre. ***Number of osmoles per litre*** - **Osmolarity** is a measure of the **solute concentration** in a solution, specifically the number of **osmoles of solute per liter of solution**. - It is often used in clinical settings to assess the **concentration of dissolved particles** in bodily fluids like plasma. *Number of osmoles per kg* - This definition describes **osmolality**, which measures the concentration of a solution as the **number of osmoles of solute per kilogram of solvent**. - While related, osmolarity and osmolality are distinct terms, with osmolality being less affected by temperature and pressure changes. *Weight of solute per litre of solution* - This definition describes a **mass concentration** (e.g., g/L), but it does not account for the **number of osmotically active particles**. - Different solutes can have the same weight but varying numbers of particles (e.g., 1 mol of glucose vs. 1 mol of NaCl dissociates into 2 particles). *Weight of solvent per litre of solution* - This statement incorrectly relates to solvent quantity rather than solute concentration and is not a standard definition for osmolarity or any related osmotic property. - The focus of osmolarity is on the concentration of the **dissolved particles (solute)**, not the weight of the solvent.

Q: IVC filter is used in the following situations except -

As primary treatment for acute DVT. ***As primary treatment for acute DVT*** - The **primary treatment** for **acute deep vein thrombosis (DVT)** is **anticoagulation therapy** (heparin, warfarin, or DOACs) to prevent clot propagation and embolization. - An **IVC filter** is **NOT primary therapy**—it is reserved for specific situations and does not treat the underlying thrombosis. - **Indications for IVC filter include:** - Absolute **contraindication to anticoagulation** (active bleeding, recent hemorrhagic stroke) - **Recurrent PE despite adequate anticoagulation** - Complications from anticoagulation therapy - Therefore, using IVC filter as primary treatment for acute DVT is **incorrect and not indicated**. *Negligible size of emboli* - While IVC filters trap **large emboli**, the concept of "negligible size emboli" is not a standard clinical consideration for filter placement. - IVC filters are indicated based on **risk of PE** and **contraindications to anticoagulation**, not based on emboli size assessment. *To reduce symptoms* - **IVC filters** do not reduce symptoms of DVT such as pain, swelling, or discomfort. - They function as a **mechanical barrier** to prevent emboli from reaching pulmonary circulation. - Symptom management requires anticoagulation, compression therapy, and leg elevation. *To prevent progress of native blood vessel disease* - IVC filters do not influence progression of underlying **vascular disease** such as atherosclerosis or chronic venous insufficiency. - Their sole function is **mechanical prevention of PE**, not disease modification.

Q: What is the appropriate treatment for an incidentally detected appendicular carcinoid tumor measuring 2.5 cm?

Right hemicolectomy. ***Right hemicolectomy*** - An appendiceal carcinoid tumor **larger than 2 cm** (or with **mesoappendix invasion, positive margins, or high-grade features**) warrants a right hemicolectomy due to a significantly higher risk of lymph node metastasis (20-30%). - This 2.5 cm tumor clearly exceeds the 2 cm threshold, making right hemicolectomy the standard of care. - This procedure ensures adequate oncological margins and removal of regional lymph nodes, which is crucial for complete treatment. *Limited resection of the right colon* - This option is insufficient for an appendiceal carcinoid of this size, as it may not remove all regional lymph nodes or provide adequate oncological margins. - Limited resection lacks the systematic lymphadenectomy required for tumors exceeding 2 cm. *Total colectomy* - This is an **overly aggressive** and unnecessary procedure for an isolated appendiceal carcinoid tumor, even one of this size. - Total colectomy is typically reserved for diffuse colonic involvement, multifocal tumors, or specific genetic syndromes, which is not indicated here. *Appendicectomy* - An appendicectomy alone is only appropriate for very small appendiceal carcinoid tumors, typically **less than 1 cm** in size, with negative margins and without evidence of mesoappendix invasion or aggressive features. - For a 2.5 cm tumor, the risk of regional lymph node involvement (20-30%) is too high for appendicectomy to be considered adequate oncological treatment.

Question 1

Azygos vein drains into:

Accepted Answer

Superior vena cava

Answer

Left brachiocephalic vein

Answer

Inferior vena cava

Answer

Right brachiocephalic vein

Question 2

Where is the neurovascular plane located in the anterior abdominal wall?

Accepted Answer

Between internal oblique and transversus abdominis

Answer

Between external oblique and internal oblique

Answer

Below transversus abdominis

Answer

Above external oblique

Question 3

Ovarian fossa is formed by all except?

Accepted Answer

Round ligament of ovary

Answer

Internal iliac artery

Answer

Ureter

Answer

Obliterated umbilical artery

Question 4

Which of the following is not a branch of the inferior mesenteric artery?

Accepted Answer

Middle rectal

Answer

Left colic

Answer

Superior rectal

Answer

Sigmoidal artery

Question 5

What does Chamberlain's line refer to in anatomical terms?

Accepted Answer

Palate to foramen magnum

Answer

Palate to occiput

Answer

Palate to temporal

Answer

Palate to parietal

Question 6

In the context of cell membrane composition, what is the typical weight ratio of protein to lipid?

Accepted Answer

1 : 1

Answer

1 : 2

Answer

4 : 1

Answer

2 : 1

Question 7

What is the Bohr effect in relation to hemoglobin's affinity for oxygen?

Accepted Answer

Decrease in O2 affinity of hemoglobin when the pH of blood falls

Answer

Decrease in CO2 affinity of hemoglobin when the pH of blood falls

Answer

Decrease in O2 affinity of hemoglobin when the pH of blood rises

Answer

Decrease in CO2 affinity of hemoglobin when the pH of blood rises

Question 8

Osmolarity is defined as?

Accepted Answer

Number of osmoles per litre

Answer

Number of osmoles per kg

Answer

Weight of solute per litre of solution

Answer

Weight of solvent per litre of solution

Question 9

IVC filter is used in the following situations except -

Accepted Answer

As primary treatment for acute DVT

Answer

To reduce symptoms

Answer

Negligible size of emboli

Answer

To prevent progress of native blood vessel disease

Question 10

What is the appropriate treatment for an incidentally detected appendicular carcinoid tumor measuring 2.5 cm?

Accepted Answer

Right hemicolectomy

Answer

Limited resection of the right colon

Answer

Total colectomy

Answer

Appendicectomy

NEET-PG 2012

Anatomy

Biochemistry

Physiology

Surgery