NEET-PG 2012 Practice Questions

Q: What is the classification of the Y chromosome?

Submetacentric. ***Submetacentric*** - The **Y chromosome** is classified as submetacentric because its **centromere** is located off-center, resulting in two arms of unequal length. - The short arm (Yp) is smaller than the long arm (Yq), but not as disproportionate as in acrocentric chromosomes. - The **X chromosome** is also submetacentric, making both sex chromosomes belong to this category. *Metacentric* - A **metacentric chromosome** has its **centromere** located in the middle, resulting in two arms of approximately equal length. - Examples include chromosomes 1, 3, 16, 19, and 20, which have nearly equal arm ratios unlike the Y chromosome. *Acrocentric* - An **acrocentric chromosome** has its **centromere** located very close to one end, creating one very short arm and one very long arm. - The five acrocentric human chromosomes are **13, 14, 15, 21, and 22**, which possess satellite DNA and nucleolar organizing regions (NORs) on their short arms. - The **Y chromosome is NOT acrocentric** despite historical confusion; it has a more centrally positioned centromere than true acrocentric chromosomes. *None of the options* - This option is incorrect because the Y chromosome has a specific and well-established classification as **submetacentric** based on its centromere position and arm ratio.

Q: Haploid number of chromosomes is first seen in?

Secondary spermatocyte. ***Secondary spermatocyte*** - A secondary spermatocyte is formed after **meiosis I**, where the homologous chromosomes are separated, resulting in a cell with a **haploid number of chromosomes (n)**, although each chromosome still consists of two sister chromatids. - This is the **first stage** where haploidy is achieved in spermatogenesis. - These cells are transient and quickly undergo meiosis II to form spermatids. *Spermatogonia* - Spermatogonia are **diploid (2n)** germline stem cells that undergo mitosis to produce more spermatogonia or differentiate into primary spermatocytes. - They contain the full complement of chromosomes found in somatic cells. *Primary spermatocytes* - Primary spermatocytes are also **diploid (2n)** cells that enter meiosis I. - Before meiosis I, DNA replication occurs, so each chromosome consists of two sister chromatids, but the cell still maintains a diploid chromosome number. *Spermatids* - Spermatids are formed after **meiosis II** from secondary spermatocytes and are also **haploid (n)**. - However, secondary spermatocytes become haploid **earlier** in the process, immediately following the reductional division of meiosis I.

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: Which structure(s) passes behind the inguinal ligament:

All of the options. ***Correct: All of the options*** All three structures pass deep to (behind) the inguinal ligament as they transition from the pelvis/abdomen into the thigh [1]. The inguinal ligament forms the superior border of the femoral triangle [1]. ***Femoral branch of genitofemoral nerve (Correct)*** - Pierces the **psoas major** muscle and descends along its anterior surface - Passes through the **lacuna musculorum** (lateral compartment) deep to the inguinal ligament - Lies **lateral to the femoral artery** - Provides sensory innervation to the skin over the femoral triangle ***Femoral vein (Correct)*** - Continuation of the popliteal vein from the lower limb - Passes through the **lacuna vasorum** (medial compartment/femoral canal) within the **femoral sheath** - Located **medial to the femoral artery** behind the inguinal ligament [1] - Carries deoxygenated blood back to the heart via the external iliac vein ***Psoas major (Correct)*** - Major hip flexor muscle originating from lumbar vertebrae (T12-L5) - Passes through the **lacuna musculorum** deep to the inguinal ligament - Located **lateral to the femoral vessels** - Combines with iliacus to form iliopsoas, inserting on the lesser trochanter of femur

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: Right ovarian artery is a branch of ?

Abdominal aorta. ***Abdominal aorta*** - The **right ovarian artery** typically originates directly from the **abdominal aorta**, just inferior to the renal arteries [1]. - This is a direct branch, supplying blood to the **right ovary**, **fallopian tube**, and surrounding structures [1]. *Right internal iliac* - The **internal iliac artery** primarily supplies the **pelvic organs**, gluteal region, and medial thigh [1]. - While it has branches to pelvic structures, the ovarian artery does not originate from it. *Common iliac* - The **common iliac artery** bifurcates into the **internal and external iliac arteries** at the level of the sacroiliac joint. - It does not directly give off the ovarian artery. *External iliac* - The **external iliac artery** continues as the **femoral artery** below the inguinal ligament, primarily supplying the lower limb. - It does not give off branches to the ovary.

Q: Cricoid cartilage lies at which vertebral level?

C6. **C6** - The **cricoid cartilage** is an important anatomical landmark, as it signifies the transition from the **laryngopharynx** to the **esophagus** and the start of the **trachea**. - Its location at **C6 vertebral level** is significant for procedures like tracheostomy and in identifying the narrowest part of the adult airway. *C3* - The C3 vertebral level is typically associated with the **hyoid bone**, which is superior to the cricoid cartilage. - The **epiglottis** and the superior aspect of the larynx are more commonly found at C3-C4. *T1* - The T1 vertebral level is in the **thoracic spine**, well below the neck, and is associated with the **apex of the lung** and the **first rib**. - The airway structures at this level are primarily the **trachea** as it enters the thorax. *T4* - The T4 vertebral level is significant as it marks the approximate location of the **carina**, where the trachea bifurcates into the main bronchi. - This level is much lower than the larynx and cricoid cartilage.

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

What is the classification of the Y chromosome?

Accepted Answer

Submetacentric

Answer

Metacentric

Answer

Acrocentric

Answer

None of the options

Question 2

Haploid number of chromosomes is first seen in?

Accepted Answer

Secondary spermatocyte

Answer

Spermatogonia

Answer

Primary spermatocytes

Answer

Spermatids

Question 3

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 4

Which structure(s) passes behind the inguinal ligament:

Accepted Answer

All of the options

Answer

Femoral branch of genitofemoral nerve

Answer

Femoral vein

Answer

Psoas major

Question 5

Azygos vein drains into:

Accepted Answer

Superior vena cava

Answer

Left brachiocephalic vein

Answer

Inferior vena cava

Answer

Right brachiocephalic vein

Question 6

Right ovarian artery is a branch of ?

Accepted Answer

Abdominal aorta

Answer

Right internal iliac

Answer

Common iliac

Answer

External iliac

Question 7

Cricoid cartilage lies at which vertebral level?

Accepted Answer

C6

Answer

C3

Answer

T1

Answer

T4

Question 8

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 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

Physiology

Surgery