NEET-PG 2015 Practice Questions

Q: Intercostal nerve is a branch of?

Ventral rami of thoracic spinal nerves. ***Ventral rami of thoracic spinal nerves*** - Intercostal nerves are direct continuations of the **ventral rami of the thoracic spinal nerves** (T1-T11) [1]. - These nerves run within the **intercostal spaces**, providing sensory and motor innervation to the thoracic wall [2]. *Brachial plexus* - The brachial plexus is formed by the **ventral rami of spinal nerves C5-T1**. - It primarily innervates the **upper limb**, not the intercostal spaces. *Dorsal rami of thoracic spinal nerves* - The dorsal rami of thoracic spinal nerves supply the **deep back muscles** and the skin over the back. - They do not contribute to the innervation of the intercostal spaces or the anterior/lateral thoracic wall. *Ventral rami of cervical spinal nerves* - The ventral rami of cervical spinal nerves form the **cervical plexus (C1-C4)** and contribute to the **brachial plexus (C5-T1)**. - They innervate structures in the neck, diaphragm, and upper limb, but not the intercostal region.

Q: What is the correct sequence of uterine blood flow?

Uterine A → Arcuate A → Radial A → Spiral A. ***Uterine A → Arcuate A → Radial A → Spiral A*** - The **uterine artery** is the primary blood supply, branching into several arteries within the myometrium. - **Arcuate arteries** encircle the uterus, giving off perpendicular branches called **radial arteries**, which then give rise to the **spiral arteries** that supply the endometrium [1]. *Uterine A → Radial A → Arcuate A → Spiral A* - This sequence is incorrect because **radial arteries** arise from **arcuate arteries**, not the other way around. - **Arcuate arteries** are larger circumferential vessels that branch into the smaller radial arteries. *Uterine A → Spiral A → Radial A → Arcuate A* - This sequence is highly incorrect as **spiral arteries** are the most distal branches supplying the endometrium, not preceding radial or arcuate arteries [1]. - The flow is from larger to smaller vessels, with **spiral arteries** being the smallest and most terminal. *Uterine A → Arcuate A → Spiral A → Radial A* - This sequence incorrectly places **spiral arteries** before **radial arteries**. - **Radial arteries** are the immediate precursors to **spiral arteries**, providing direct branches to them.

Q: What is the uppermost structure in left lung hilum?

Pulmonary artery. ***Pulmonary artery*** - In the **left lung hilum**, the **pulmonary artery** typically lies superior to the bronchus. - This anatomical position helps differentiate it from the relations in the right lung hilum, where the pulmonary artery is anterior to the bronchus. *Pulmonary vein* - The **pulmonary veins** are usually located anterior and inferior to the bronchus in both lung hila. - They tend to be the most anterior and inferior structures carrying oxygenated blood from the lungs. *Bronchial artery* - **Bronchial arteries** are smaller vessels that typically run on the posterior surface of the bronchi. - They are not considered the uppermost main structure in the hilum. *Left mainstem bronchus* - The **left mainstem bronchus** is usually found inferior to the pulmonary artery and posterior to the pulmonary veins in the left hilum. - It is a prominent structure but not the most superior.

Q: Which of the following is NOT a component of the spermatic cord?

Poupart's ligament. ***Poupart's ligament*** - **Poupart's ligament**, also known as the **inguinal ligament**, is a fibrous band extending from the anterior superior iliac spine to the pubic tubercle and forms the **inferior boundary of the inguinal canal**. - It is a boundary structure of the inguinal canal but is **not contained within the spermatic cord** itself [1]. *Genito-femoral nerve* - The **genital branch of the genitofemoral nerve** passes through the inguinal canal and supplies the **cremaster muscle** and scrotal skin [1]. - While it accompanies the spermatic cord through the canal, it is **not traditionally listed as a component of the spermatic cord** in standard anatomical classification, though some sources may include it [1]. *Vas deferens* - The **vas deferens** (ductus deferens) is a thick muscular tube that transports sperm from the epididymis to the ejaculatory duct. - It is a **primary structural component of the spermatic cord** and is the most prominent palpable structure within it. *Pampiniform plexus* - The **pampiniform plexus** is a network of 8-12 veins that surrounds the testicular artery within the spermatic cord. - This venous plexus provides a **countercurrent heat exchange mechanism** for thermoregulation of the testes and is a major component of the spermatic cord.

Q: Which protein is defective in dilated cardiomyopathy?

Dystrophin. ***Dystrophin*** - **Dystrophin** is a crucial protein in the **muscle cell membrane** that anchors the cytoskeleton to the extracellular matrix. - Defects in dystrophin lead to sarcolemmal fragility, causing muscle damage and can result in **dilated cardiomyopathy**, especially in conditions like **Duchenne muscular dystrophy** [1]. *Myosin* - **Myosin** is a fundamental **motor protein** involved in muscle contraction, forming the thick filaments. - While mutations in myosin can cause various cardiac conditions, like hypertrophic cardiomyopathy, direct primary defects in myosin are not typically identified as the cause of dilated cardiomyopathy [2]. *Troponin* - **Troponin** is a protein complex that regulates muscle contraction by controlling the interaction between actin and myosin, particularly in response to calcium. - Although troponins are vital for cardiac function and are released during myocardial injury, their primary defect is not typically implicated in the etiology of dilated cardiomyopathy [2]. *Tropomyosin* - **Tropomyosin** is a protein that winds around actin filaments and, along with troponin, regulates the binding of myosin to actin. - While essential for muscle contraction, direct defects in tropomyosin are not a common genetic cause of dilated cardiomyopathy. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Peripheral Nerves and Skeletal Muscles, pp. 1244-1245. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, p. 574.

Q: What is a distinguishing feature of reticulocytes?

Presence of residual RNA and ribosomes. ***Presence of residual RNA and ribosomes*** - This is the **defining and most distinguishing feature** of reticulocytes that differentiates them from mature red blood cells. - Reticulocytes contain residual **ribosomal RNA** and other organelles that are lost when they mature into erythrocytes. - This residual RNA forms a **reticular (network-like) pattern** when stained with supravital stains like **new methylene blue** or **brilliant cresyl blue**, which is the basis for their name and identification. - The presence of RNA allows for **reticulocyte counting**, an important marker of bone marrow erythropoietic activity. *Slightly larger in size than RBCs* - While reticulocytes may be slightly larger (polychromatophilic appearance), size variation is **not specific** and overlaps significantly with mature RBCs. - Size is not a reliable distinguishing feature and is not used for identification or counting. *Mature in bone marrow* - Reticulocytes are **released from the bone marrow** as immature red cells and complete their maturation in the **peripheral circulation** over 24-48 hours. - They do not fully mature in the bone marrow; their presence in peripheral blood is normal. *Constitute approximately 1% of the red cells* - Normal reticulocyte count is **0.5-2%** (or approximately 1%) of total red blood cells in healthy adults. - This is a **population characteristic** indicating normal erythropoietic activity, not a distinguishing cellular feature.

Q: Which sympathomimetic drug is primarily known to increase heart rate?

Isoprenaline. ***Isoprenaline*** - **Isoprenaline** (isoproterenol) is a non-selective beta-adrenergic agonist, with a strong affinity for **β1 and β2 receptors** [1]. - Its activation of **β1 receptors** in the heart leads to a significant increase in **heart rate (positive chronotropy)** and contractility (positive inotropy) [1]. - It is the **most potent chronotropic agent** among sympathomimetics and is primarily known for increasing heart rate [2]. *Phenylephrine* - **Phenylephrine** is a selective **α1 adrenergic agonist** that causes vasoconstriction [4]. - It increases blood pressure but typically causes **reflex bradycardia** (decreased heart rate) due to baroreceptor activation. - Does NOT directly increase heart rate. *Noradrenaline* - **Noradrenaline** (norepinephrine) primarily acts on **α1 receptors** causing vasoconstriction, and to a lesser extent on **β1 receptors** [3]. - While it can stimulate β1 receptors, its predominant effect is to increase **mean arterial pressure** through vasoconstriction, often causing **reflex bradycardia** [3]. *Adrenaline* - **Adrenaline** (epinephrine) acts on **α1, β1, and β2 receptors** [4]. While it does increase heart rate via **β1 receptor** stimulation, it also causes significant **vasoconstriction** (via α1) and **vasodilation** (via β2). - Its cardiovascular effects are more complex and dose-dependent compared to isoprenaline's specific chronotropic action.

Q: Which of the following is a long-acting beta-2 agonist?

Formoterol. ***Formoterol*** - **Formoterol** is a **long-acting beta-2 agonist (LABA)** commonly used in the treatment of asthma and COPD. - It provides **bronchodilation** for up to 12 hours due to its high lipophilicity, allowing it to remain in the cell membrane and continuously activate beta-2 receptors. *Isoprenaline (non-selective adrenergic agonist)* - **Isoprenaline** is a **non-selective beta-adrenergic agonist**, meaning it activates both beta-1 and beta-2 receptors. - It is **short-acting** and primarily used as a vasodilator or to stimulate heart rate, not as a long-acting bronchodilator. *Ephedrine (non-selective adrenergic agonist)* - **Ephedrine** is a **mixed-acting sympathomimetic amine** that increases the release of norepinephrine and directly stimulates alpha and beta receptors. - It has a short duration of action and is primarily used as a decongestant or bronchodilator in emergency situations, not as a long-acting agent. *Salbutamol (short-acting beta-2 agonist)* - **Salbutamol** is a **short-acting beta-2 agonist (SABA)**, providing rapid onset but a short duration of action (typically 4-6 hours). - It is used for **relieving acute bronchospasm** and is not considered a long-acting medication for maintenance therapy.

Q: Labour pain in uterus is carried by

Sympathetic nerves. ***Sympathetic nerves*** - Pain signals from the **uterus** during the first stage of labor (cervical dilation and uterine contractions) are transmitted via **visceral afferent fibers that accompany the sympathetic nerves** through the **hypogastric plexus**. - These fibers synapse in the **thoracolumbar spinal cord** at **T10-L1 segments**, leading to referred pain in these dermatomes. - The pathway is: Uterus → Uterine plexus → Superior hypogastric plexus → Sympathetic chain → T10-L1 dorsal roots. *Splanchnic nerve* - While visceral afferents do travel with splanchnic nerves in the thoracoabdominal region, for **uterine pain** specifically, the standard medical terminology refers to **sympathetic nerves** and the **hypogastric plexus** as the primary pathway. - Splanchnic nerves typically refer to thoracic sympathetic contributions (T5-T12) to upper abdominal viscera. *Pudendal nerve* - The **pudendal nerve (S2-S4)** primarily innervates the perineum, external genitalia, and pelvic floor structures. - It transmits pain during the **second stage of labor**, particularly with stretching of the perineum and vaginal distension, but **not from the uterus itself**. *Parasympathetic nerves* - **Parasympathetic innervation (S2-S4 via pelvic splanchnic nerves)** to the uterus influences motor function but does **not transmit nociceptive (pain) signals** during labor. - These nerves are involved in visceral reflexes and efferent control, not the primary afferent pain pathway.

Q: Which of the following is considered a poor prognostic factor for schizophrenia?

Poor premorbid adjustment. **Poor premorbid adjustment** - **Poor premorbid adjustment**, indicated by difficulties in social, academic, or occupational functioning before the onset of psychosis, is a consistent predictor of a worse outcome in schizophrenia. - This suggests a more pervasive and entrenched neurodevelopmental vulnerability impacting the individual's ability to cope and integrate socially. *Blunted affect (negative symptom)* - While **blunted affect** is a negative symptom often associated with poorer outcomes than positive symptoms, it is typically considered a *symptom* of the illness rather than a primary prognostic *factor* like premorbid adjustment. - Its presence contributes to disability, but it is not as strong an independent prognostic indicator as the life trajectory prior to illness onset. *Male sex (generally poorer prognosis)* - **Male sex** is generally associated with an **earlier age of onset** and often a **more severe course** of schizophrenia. - However, compared to significant functional impairment before disease onset, it is not as strong an individual predictor of overall long-term prognosis. *Presence of depression (often associated with better outcomes)* - The **presence of depressive symptoms** in schizophrenia is often associated with a **better prognosis**. - This is because depressive features can sometimes indicate a more preserved capacity for emotional experience and insight, which can align with higher functioning.

Question 1

Intercostal nerve is a branch of?

Accepted Answer

Ventral rami of thoracic spinal nerves

Answer

Brachial plexus

Answer

Dorsal rami of thoracic spinal nerves

Answer

Ventral rami of cervical spinal nerves

Question 2

What is the correct sequence of uterine blood flow?

Accepted Answer

Uterine A → Arcuate A → Radial A → Spiral A

Answer

Uterine A → Radial A → Arcuate A → Spiral A

Answer

Uterine A → Spiral A → Radial A → Arcuate A

Answer

Uterine A → Arcuate A → Spiral A → Radial A

Question 3

What is the uppermost structure in left lung hilum?

Accepted Answer

Pulmonary artery

Answer

Pulmonary vein

Answer

Bronchial artery

Answer

Left mainstem bronchus

Question 4

Which of the following is NOT a component of the spermatic cord?

Accepted Answer

Poupart's ligament

Answer

Genito-femoral nerve

Answer

Vas deferens

Answer

Pampiniform plexus

Question 5

Which protein is defective in dilated cardiomyopathy?

Accepted Answer

Dystrophin

Answer

Tropomyosin

Answer

Myosin

Answer

Troponin

Question 6

What is a distinguishing feature of reticulocytes?

Accepted Answer

Presence of residual RNA and ribosomes

Answer

Slightly larger in size than RBCs

Answer

Mature in bone marrow

Answer

Constitute approximately 1% of the red cells

Question 7

Which sympathomimetic drug is primarily known to increase heart rate?

Accepted Answer

Isoprenaline

Answer

Phenylephrine

Answer

Noradrenaline

Answer

Adrenaline

Question 8

Which of the following is a long-acting beta-2 agonist?

Accepted Answer

Formoterol

Answer

Isoprenaline

Answer

Ephedrine

Answer

Salbutamol

Question 9

Labour pain in uterus is carried by

Accepted Answer

Sympathetic nerves

Answer

Pudendal nerve

Answer

Parasympathetic nerves

Answer

Splanchnic nerve

Question 10

Which of the following is considered a poor prognostic factor for schizophrenia?

Accepted Answer

Poor premorbid adjustment

Answer

Male sex

Answer

Presence of depression

Answer

Blunted affect

NEET-PG 2015

Anatomy

Pathology

Pharmacology

Physiology

Psychiatry