NEET-PG 2012 Practice Questions

Q: Development of labia majora is from -

Genital swelling. ***Genital swelling*** - The **labia majora** develop from the **genital (labioscrotal) swellings** in females, which are homologous to the scrotum in males [3]. - These swellings enlarge and fuse anteriorly to form the mons pubis and posteriorly to form the posterior commissures of the labia majora. *Urogenital sinus* - The **urogenital sinus** gives rise to structures like the **bladder**, **urethra**, and parts of the **vagina** in females [2]. - It does not contribute to the formation of the external labial structures. *Mullerian duct* - The **Mullerian (paramesonephric) ducts** develop into the **fallopian tubes**, **uterus**, and the **upper third of the vagina** [1], [2]. - These structures are internal reproductive organs and do not form external genitalia like the labia majora. *Genital ridge* - The **genital ridge** is the embryonic precursor to the **gonads** (ovaries or testes). - It differentiates into either ovaries or testes and does not directly form external genital structures.

Q: What type of joint is the 1st carpometacarpal joint?

Saddle. ***Saddle*** - The **1st carpometacarpal joint** (thumb CMC joint) is a classic example of a **saddle joint** due to the reciprocal concave-convex opposing surfaces of the trapezium and the first metacarpal [1]. - This unique shape allows for a wide range of motion, including **flexion/extension**, **abduction/adduction**, and **opposition**, which is crucial for thumb function. *Pivot* - A **pivot joint** allows for rotational movement around a single axis, like the **atlantoaxial joint** (C1-C2) or the **proximal radioulnar joint**. - This type of motion is not characteristic of the 1st carpometacarpal joint. *Hinge* - A **hinge joint** permits movement in only one plane, like the **elbow** or **interphalangeal joints**, allowing for **flexion and extension**. - The 1st carpometacarpal joint has a greater degree of freedom than a hinge joint. *Ball and Socket* - A **ball and socket joint** offers the greatest range of motion, allowing for movement in all planes, including **circumduction and rotation**, such as the **shoulder** and **hip joints**. - While the 1st carpometacarpal joint is highly mobile, it does not achieve the full range of motion of a ball and socket joint.

Q: Which cranial nerve is not associated with the nucleus ambiguus?

Cranial Nerve XII (Hypoglossal). ***Cranial Nerve XII (Hypoglossal)*** - The **hypoglossal nucleus** in the medulla is the origin for CN XII, which primarily controls **tongue movements** [1]. - It does not receive motor fibers from the nucleus ambiguus, as its function is unrelated to the pharyngeal or laryngeal musculature. *Cranial Nerve X (Vagus)* - Motor fibers for the muscles of the **pharynx** and **larynx** from the nucleus ambiguus contribute to the vagus nerve. - The vagus nerve also provides parasympathetic innervation to the **thoracic and abdominal viscera**. *Cranial Nerve XI (Accessory)* - Cranial root contributions from the nucleus ambiguus exit with the vagus nerve to innervate the **laryngeal muscles**. - The **spinal root** of the accessory nerve, originating from the cervical spinal cord, innervates the **sternocleidomastoid** and **trapezius muscles**. *Cranial Nerve IX (Glossopharyngeal)* - The nucleus ambiguus provides motor innervation for the **stylopharyngeus muscle** via the glossopharyngeal nerve. - This muscle plays a role in **swallowing** and elevates the pharynx.

Q: The nutrient artery to the femur is?

Profunda femoris artery. ***Profunda femoris artery*** - The **profunda femoris artery** (deep femoral artery) is the main blood supply to the **femur's diaphysis** via its perforating branches. - Typically, the **second perforating branch** gives rise to the nutrient artery, which enters the bone through the **nutrient foramen** in the middle third of the femoral shaft. *Femoral artery* - The **femoral artery** is the main artery of the thigh and gives off several branches, including the profunda femoris artery. - While it is the source of blood for the entire lower limb, it does not directly give rise to the main **nutrient artery of the femur**. *Popliteal artery* - The **popliteal artery** is a continuation of the femoral artery in the popliteal fossa behind the knee. - It primarily supplies structures around the knee joint and the lower leg, not the direct **diaphyseal nutrient supply** to the femur. *Medial circumflex femoral artery* - The **medial circumflex femoral artery** primarily supplies the head and neck of the femur, crucial for its vascularity, especially in children. - It does not serve as the **main nutrient artery** for the femoral shaft (diaphysis).

Q: What is the consequence of tibial nerve injury/palsy?

Loss of plantar flexion. **Loss of plantar flexion** - The **tibial nerve** innervates the muscles of the **posterior compartment of the leg**, which are primarily responsible for **plantar flexion** of the foot. - Injury to this nerve directly impairs the function of muscles like the gastrocnemius, soleus, and tibialis posterior, leading to a significant loss of the ability to point the foot downwards. *Dorsiflexion of foot at ankle joint* - **Dorsiflexion** is primarily mediated by muscles in the **anterior compartment of the leg**, such as the tibialis anterior, which are innervated by the **deep fibular nerve**. - Tibial nerve injury would not directly affect these muscles or their function; rather, it leads to issues with the opposing action. *Loss of sensation of dorsum of foot* - Sensation to the **dorsum of the foot** is primarily supplied by the **superficial fibular nerve** (for most of the dorsum) and the **deep fibular nerve** (for the first web space). - While the tibial nerve provides sensation to the sole of the foot, it does not typically innervate the dorsum. *Paralysis of muscles of anterior compartment of leg* - The muscles of the **anterior compartment of the leg** (e.g., tibialis anterior, extensor digitorum longus, extensor hallucis longus) are innervated by the **deep fibular nerve**. - A tibial nerve injury would paralyze muscles in the posterior compartment, not the anterior compartment.

Q: The right coronary artery supplies blood to all of the following structures, except?

Anterior 2/3 of ventricular septum. ***Anterior 2/3 of ventricular septum*** - The **anterior two-thirds of the interventricular septum** is primarily supplied by the **septal branches of the left anterior descending artery** (LAD) [1], a branch of the left coronary artery. - Therefore, the right coronary artery does not typically supply this region. *SA node* - The **SA node** (sinoatrial node) is the heart's natural pacemaker and receives its blood supply from the **right coronary artery** in about 60% of individuals. - Occlusion of the RCA can lead to symptomatic **bradycardia** or **SA node dysfunction**. *AV node* - The **AV node** (atrioventricular node), crucial for coordinating ventricular contraction, is supplied by the **right coronary artery** in approximately 90% of individuals [1]. - Infarcts in the RCA territory can manifest as various degrees of **heart block**. *Posterior wall of left ventricle* - The **posterior wall of the left ventricle** is predominantly supplied by the **posterior descending artery (PDA)**, which in about 80% of people, is a terminal branch of the **right coronary artery** [1]. - This supply is vital for the contractile function of the left ventricle's posterior aspect.

Q: All of the following arteries are branches of the coeliac trunk, EXCEPT which one?

Right gastric artery. ***Right gastric artery*** - The **right gastric artery** typically originates from the **proper hepatic artery**, which is a branch of the common hepatic artery. - Therefore, it is not a direct branch of the coeliac trunk itself. *Left gastric artery* - The **left gastric artery** is one of the three main direct branches of the **coeliac trunk**. - It supplies the lesser curvature of the stomach and the abdominal esophagus. *Splenic artery* - The **splenic artery** is another major direct branch of the **coeliac trunk**. - It supplies the spleen, pancreas, and parts of the stomach via various branches. *Common hepatic artery* - The **common hepatic artery** is the third main direct branch of the **coeliac trunk**. - It gives rise to the proper hepatic artery and the gastroduodenal artery, supplying the liver, gallbladder, pylorus, and duodenum.

Q: Which of these best describes the renal angle?

The angle between the 12th rib and the erector spinae. ***The angle between the 12th rib and the erector spinae*** - The **renal angle** (also known as the costovertebral angle) is the space formed by the junction of the **12th rib** and the **erector spinae muscles** laterally. - This anatomical landmark is clinically significant for assessing **kidney pain** or inflammation (e.g., in pyelonephritis) through percussion. *The angle between the latissimus dorsi and the 12th rib* - While the **latissimus dorsi** is a significant back muscle, it is not the primary anatomical landmark that defines the renal angle. - The renal angle specifically refers to the relationship between the rib cage and the deeper spinal muscles. *The angle between the erector spinae and the iliac crest* - This description refers to a region lower down on the back, closer to the **pelvis**, and not directly related to the position of the kidneys. - The **iliac crest** defines the upper border of the pelvis, far from the kidney's typical location relative to the 12th rib. *The angle between the 12th rib and the rectus abdominis* - The **rectus abdominis** muscle is located on the anterior (front) aspect of the abdomen, involved in trunk flexion. - This muscle is anatomically distinct and separate from the posterior flank region where the kidneys are located and where the renal angle is assessed.

Q: Which glycogen storage disease also presents as a lysosomal storage disease?

Pompe's disease. ***Pompe's disease*** - Also known as **glycogen storage disease type II**, it is caused by a deficiency of **acid alpha-glucosidase (GAA)**, a *lysosomal enzyme*. - This deficiency leads to the accumulation of **glycogen in lysosomes**, particularly affecting muscle tissue, thereby earning its classification as both a glycogen storage disease and a lysosomal storage disease. *Von Gierke's disease* - This is **glycogen storage disease type I** and is due to a deficiency in **glucose-6-phosphatase**. - It primarily affects the **liver and kidneys**, causing severe **hypoglycemia** and **lactic acidosis**, but it is not classified as a lysosomal storage disease. *McArdle's disease* - This is **glycogen storage disease type V**, caused by a deficiency in **muscle glycogen phosphorylase (myophosphorylase)**. - It manifests as **exercise intolerance** and muscle pain, but it does not involve lysosomal enzyme defects or glycogen accumulation in lysosomes. *Andersen's disease* - This is **glycogen storage disease type IV**, caused by a deficiency in the **glycogen branching enzyme**. - It leads to the formation of **abnormal glycogen structures**, primarily affecting the liver and causing early liver failure, but it is not a lysosomal storage disorder.

Q: Which of the following statements regarding the lower esophageal sphincter is TRUE?

It relaxes in response to swallowing.. ***It relaxes in response to swallowing.*** - The **lower esophageal sphincter (LES)** normally maintains high resting tone to prevent gastroesophageal reflux but **relaxes completely during swallowing** to allow passage of food into the stomach. - This relaxation (called **receptive relaxation**) is mediated by **vagal nerve stimulation** through release of nitric oxide (NO) and vasoactive intestinal peptide (VIP). - The relaxation occurs **before the peristaltic wave arrives**, allowing coordinated transit of the bolus. *It remains contracted during swallowing to prevent regurgitation.* - This is **incorrect** - the LES must **relax during swallowing** to allow food passage into the stomach. - Failure of LES relaxation during swallowing is the pathophysiology of **achalasia**, leading to dysphagia. - The LES only maintains contraction between swallows to prevent reflux. *Its tone is primarily influenced by the myogenic properties of the smooth muscle.* - While the LES contains smooth muscle with intrinsic myogenic properties, its tone is **predominantly regulated by neural and hormonal factors**. - **Neural control:** Vagal cholinergic pathways (increase tone), non-adrenergic non-cholinergic (NANC) pathways with NO and VIP (decrease tone). - **Hormonal factors:** Gastrin increases tone, while progesterone, CCK, and secretin decrease tone. *It contracts in response to gastric distension.* - This is **incorrect** - gastric distension actually triggers **transient LES relaxations (TLESRs)**, which are the primary mechanism of physiological reflux. - TLESRs are vagally mediated reflex responses that allow venting of gastric air. - Increased LES contraction in response to gastric distension would be counterproductive.

Question 1

Development of labia majora is from -

Accepted Answer

Genital swelling

Answer

Urogenital sinus

Answer

Mullerian duct

Answer

Genital ridge

Question 2

What type of joint is the 1st carpometacarpal joint?

Accepted Answer

Saddle

Answer

Pivot

Answer

Hinge

Answer

Ball and Socket

Question 3

Which cranial nerve is not associated with the nucleus ambiguus?

Accepted Answer

Cranial Nerve XII (Hypoglossal)

Answer

Cranial Nerve X (Vagus)

Answer

Cranial Nerve XI (Accessory)

Answer

Cranial Nerve IX (Glossopharyngeal)

Question 4

The nutrient artery to the femur is?

Accepted Answer

Profunda femoris artery

Answer

Femoral artery

Answer

Popliteal artery

Answer

Medial circumflex femoral artery

Question 5

What is the consequence of tibial nerve injury/palsy?

Accepted Answer

Loss of plantar flexion

Answer

Dorsiflexion of foot at ankle joint

Answer

Loss of sensation of dorsum of foot

Answer

Paralysis of muscles of anterior compartment of leg

Question 6

The right coronary artery supplies blood to all of the following structures, except?

Accepted Answer

Anterior 2/3 of ventricular septum

Answer

Posterior wall of left ventricle

Answer

SA node

Answer

AV node

Question 7

All of the following arteries are branches of the coeliac trunk, EXCEPT which one?

Accepted Answer

Right gastric artery

Answer

Splenic artery

Answer

Left gastric artery

Answer

Common hepatic artery

Question 8

Which of these best describes the renal angle?

Accepted Answer

The angle between the 12th rib and the erector spinae

Answer

The angle between the latissimus dorsi and the 12th rib

Answer

The angle between the erector spinae and the iliac crest

Answer

The angle between the 12th rib and the rectus abdominis

Question 9

Which glycogen storage disease also presents as a lysosomal storage disease?

Accepted Answer

Pompe's disease

Answer

Von Gierke's disease

Answer

McArdle's disease

Answer

Andersen's disease

Question 10

Which of the following statements regarding the lower esophageal sphincter is TRUE?

Accepted Answer

It relaxes in response to swallowing.

Answer

It remains contracted during swallowing to prevent regurgitation.

Answer

Its tone is primarily influenced by the myogenic properties of the smooth muscle.

Answer

It contracts in response to gastric distension.

NEET-PG 2012

Anatomy

Biochemistry

Physiology