NEET-PG 2021 Previous Year Questions Practice Questions

Q: Pen Test is for which nerve

Median Nerve. ***Median Nerve*** - The **pen test** (or pen-holding test) assesses the ability to perform **precision grip** by pinching a pen between the thumb and index finger - This tests **thumb opposition and flexion**, which are controlled by the **thenar muscles** (abductor pollicis brevis, opponens pollicis, and flexor pollicis brevis) innervated by the median nerve - The median nerve also controls the **lateral two lumbricals** for fine finger movements essential for holding objects like a pen - **Clinical significance**: Inability to perform this test indicates median nerve injury (e.g., carpal tunnel syndrome) *Musculocutaneous* - Innervates the **anterior compartment of the arm**: biceps brachii, brachialis, and coracobrachialis - Controls **elbow flexion** and provides sensory innervation to the lateral forearm - Does not control hand muscles or precision grip functions *Radial nerve* - Innervates **extensors of the wrist, fingers, and thumb** in the posterior compartment of the forearm - Controls **wrist extension** and **finger extension** at the MCP joints - Radial nerve injury causes **wrist drop**, not impaired precision grip *Ulnar nerve* - Controls most **intrinsic hand muscles** including interossei, medial two lumbricals, and adductor pollicis - Tested by **Froment's sign** (compensatory thumb IP flexion when pinching paper due to adductor pollicis weakness) - Ulnar nerve injury affects **power grip** and finger abduction/adduction, not the precision pinch required for the pen test *Axillary nerve* - Innervates the **deltoid** and **teres minor** muscles in the shoulder - Controls **shoulder abduction** and provides sensation over the lateral upper arm - Has no role in hand function or precision grip [Practice more NEET-PG 2021 questions on OnCourse]

Q: A young boy presents with multiple humerus fractures, resulting in loss of sensation over the lateral side of the forearm, along with difficulty in elbow flexion and forearm supination. What is the most likely nerve injury responsible for these symptoms?

Musculocutaneous nerve. ***Musculocutaneous nerve*** - The **musculocutaneous nerve** innervates the biceps brachii and brachialis muscles, responsible for **elbow flexion** and **forearm supination**, and provides sensation to the **lateral forearm** via the lateral cutaneous nerve of the forearm. - A fracture of the humerus can damage this nerve, leading to the observed **motor and sensory deficits**. *Median nerve* - The median nerve primarily controls **flexion of the wrist and fingers**, and **pronation of the forearm**, as well as sensation to the palmar aspect of the thumb, index, middle, and radial half of the ring finger. - Its injury would not typically cause difficulty with **elbow flexion** or sensory loss over the **lateral forearm**. *Axillary* - The axillary nerve primarily innervates the **deltoid** and **teres minor muscles**, important for shoulder abduction and external rotation. - An injury would lead to **weakness in shoulder abduction** and sensory loss over the lateral shoulder (regimental badge area), not the lateral forearm. *Radial nerve* - The radial nerve controls **extension of the wrist and fingers** and sensation over the posterior arm, forearm, and hand. - Injury typically results in **wrist drop** and difficulty extending the arm, not primarily elbow flexion or lateral forearm sensation. *Ulnar nerve* - The ulnar nerve innervates intrinsic hand muscles and flexor carpi ulnaris, controlling **finger abduction/adduction** and **ulnar wrist flexion**. - Sensory distribution includes the medial hand and medial 1.5 fingers, not the **lateral forearm**. - Injury causes **claw hand deformity** and sensory loss in the medial hand, not the symptoms described. [Practice more NEET-PG 2021 questions on OnCourse]

Q: Which blood vessel carries deoxygenated blood back to the placenta?

Umbilical artery. ***Umbilical artery*** - The **umbilical arteries** carry **deoxygenated blood** and waste products from the fetus to the placenta [2], [3]. - There are typically **two umbilical arteries** that branch off the internal iliac arteries in the fetus [2]. *Inferior vena cava* - The **inferior vena cava** carries deoxygenated blood from the lower body back to the **fetal heart**, not the placenta. - In a fetus, the inferior vena cava also carries **oxygenated blood** from the umbilical vein through the ductus venosus [1]. *Umbilical vein* - The **umbilical vein** carries **oxygenated blood** and nutrients from the placenta to the fetus [1]. - It bypasses the liver via the **ductus venosus** to deliver blood directly to the inferior vena cava [1]. *Ductus venosus* - The **ductus venosus** is a shunt that allows **oxygenated blood** from the umbilical vein to bypass the fetal liver [1]. - It connects the umbilical vein directly to the **inferior vena cava**, not to the placenta with deoxygenated blood [1]. [Practice more NEET-PG 2021 questions on OnCourse]

Q: Structure preventing vertical descent of spleen

Phrenocolic ligament. ***Phrenocolic ligament*** - The **phrenocolic ligament** is a fold of peritoneum that extends from the left colic (splenic) flexure of the colon to the diaphragm. - It forms a shelf or sling underneath the spleen, providing crucial support and preventing its **vertical descent**. *Ligamentum teres* - The **ligamentum teres hepatis** is the remnant of the obliterated umbilical vein, found in the free margin of the falciform ligament. - It connects the umbilicus to the liver and plays no role in supporting the spleen. *Ligamentum flavum* - The **ligamentum flavum** is a series of elastic ligaments connecting the laminae of adjacent vertebrae in the spinal column. - It is a component of the vertebral column and has no anatomical or functional relationship with the spleen. *Hepatogastric ligament* - The **hepatogastric ligament** is part of the lesser omentum, extending from the liver to the lesser curvature of the stomach. - Its primary function is to contain the **gastric arteries** and connect these organs, not to support the spleen. *Lienorenal ligament* - The **lienorenal ligament** (splenorenal ligament) connects the hilum of the spleen to the anterior surface of the left kidney. - While it provides **lateral support** to the spleen, it does not prevent **vertical descent** as effectively as the phrenocolic ligament. [Practice more NEET-PG 2021 questions on OnCourse]

Q: Which nerve is responsible for gag reflex

9th Cranial Nerve. ***9th Cranial Nerve*** - The **glossopharyngeal nerve (CN IX)** is primarily responsible for the **afferent (sensory)** limb of the gag reflex, detecting touch in the posterior pharynx. - It transmits sensory information to the **brainstem**, initiating the efferent response via the vagus nerve. - CN IX is considered the nerve "responsible for" the gag reflex as it **detects and initiates** the protective response. *10th Cranial Nerve* - The **vagus nerve (CN X)** provides the **efferent (motor)** limb of the gag reflex, causing pharyngeal muscle contraction. - While essential for the motor response, CN IX is the primary sensory trigger that initiates the reflex. - Both nerves work together, but CN IX is the **detection nerve** that starts the reflex arc. *11th Cranial Nerve* - The **spinal accessory nerve (CN XI)** primarily innervates the **sternocleidomastoid** and **trapezius muscles**, controlling head and shoulder movements. - It has no direct role in the **gag reflex**. *6th Cranial Nerve* - The **abducens nerve (CN VI)** is responsible for the **lateral rectus muscle** of the eye, controlling **abduction of the eyeball**. - It does not participate in the complex **sensory or motor pathways** of the gag reflex. *7th Cranial Nerve* - The **facial nerve (CN VII)** controls **facial expressions**, taste from the anterior two-thirds of the tongue, and some glandular secretions. - While it has some role in taste and salivation, it is not the primary nerve for the **gag reflex**. [Practice more NEET-PG 2021 questions on OnCourse]

Question 1

Pen Test is for which nerve

Accepted Answer

Median Nerve

Answer

Radial nerve

Answer

Ulnar nerve

Answer

Musculocutaneous

Answer

Axillary nerve

Question 2

A young boy presents with multiple humerus fractures, resulting in loss of sensation over the lateral side of the forearm, along with difficulty in elbow flexion and forearm supination. What is the most likely nerve injury responsible for these symptoms?

Accepted Answer

Musculocutaneous nerve

Answer

Median nerve

Answer

Axillary

Answer

Radial nerve

Answer

Ulnar nerve

Question 3

Which blood vessel carries deoxygenated blood back to the placenta?

Accepted Answer

Umbilical artery

Answer

Inferior vena cava

Answer

Umbilical vein

Answer

Ductus venosus

Question 4

Structure preventing vertical descent of spleen

Accepted Answer

Phrenocolic ligament

Answer

Ligamentum teres

Answer

Ligamentum flavum

Answer

Hepatogastric ligament

Answer

Lienorenal ligament

Question 5

Which nerve is responsible for gag reflex

Accepted Answer

9th Cranial Nerve

Answer

11th cranial nerve

Answer

6th Cranial Nerve

Answer

7th Cranial Nerve

Answer

10th Cranial Nerve

Question 6

A patient underwent a coronary artery bypass graft (CABG) using the great saphenous vein. Post-surgery, the patient experiences neuralgia on the medial aspect of the leg and foot. Which nerve is most likely injured?

Accepted Answer

Saphenous nerve

Answer

Common peroneal nerve

Answer

Sural nerve

Answer

Tibial nerve

Answer

Superficial peroneal nerve

Question 7

A patient presents with cold skin, fatigue, shortness of breath on exertion, and an enlarged liver. Upon examination, his jugular venous pressure (JVP) reveals a prominent "a" wave. What is the most likely cause of the elevated "a" wave in this patient?

Accepted Answer

Tricuspid Stenosis

Answer

Mitral Stenosis

Answer

Tricuspid Regurgitation

Answer

Mitral Regurgitation

Answer

Pulmonary Stenosis

Question 8

Beta 2 receptors act via which of the following secondary messenger systems

Accepted Answer

Adenylate Cyclase

Answer

Phospholipase C

Answer

Guanylate Cyclase

Answer

Direct ion channel activation

Answer

Tyrosine Kinase

Question 9

A child presented with dehydration and was supplemented with ORS solution for management. Which of the following transporters help in the absorption of glucose from GIT?

Accepted Answer

SGLT 1

Answer

GLUT 2

Answer

SGLT 2

Answer

GLUT 1

Question 10

The body fluid compartments of a patient were measured, showing the following ion concentrations:

- Sodium (Na): $10 \mathrm{mEq} / \mathrm{L}$
- Potassium (K): $140 \mathrm{mEq} / \mathrm{L}$
- Chloride (Cl): $15 \mathrm{mEq} / \mathrm{L}$

Based on these values, which fluid compartment is being described?

Accepted Answer

ICF

Answer

Plasma

Answer

Interstitial fluid

Answer

ECF

NEET-PG 2021

Anatomy

Internal Medicine

Pharmacology

Physiology