Anatomy
5 questionsWhich of the following statements about the mammary gland is false?
Which is the primary muscle causing supination of the forearm?
All are infraclavicular branches of brachial plexus except ?
What is the largest branch of the brachial plexus?
All are supplied by the anterior interosseous nerve except which of the following?
NEET-PG 2013 - Anatomy NEET-PG Practice Questions and MCQs
Question 111: Which of the following statements about the mammary gland is false?
- A. Is a modified sweat gland
- B. Extends from 2nd to 6th rib vertically
- C. Supplied by internal mammary artery
- D. Nipple is supplied by 6th intercostal nerve (Correct Answer)
Explanation: ***Nipple is supplied by 6th intercostal nerve*** - The **nipple and areola** are primarily supplied by branches of the **4th intercostal nerve**. - The 6th intercostal nerve supplies the lower part of the breast and is not the primary innervation for the nipple. *Is a modified sweat gland* - The mammary gland, or breast, is indeed a **modified apocrine sweat gland**. - This embryological origin explains its glandular structure and function of milk production. *Extends from 2nd to 6th rib vertically* - The vertical extent of the mammary gland typically ranges from the **2nd to the 6th rib**. - This anatomical positioning is consistent with its location on the anterior thoracic wall. *Supplied by internal mammary artery* - The **internal mammary artery (internal thoracic artery)** is a major blood supply to the medial aspect of the breast [2]. - Other significant arteries include the lateral thoracic and thoracoacromial arteries for the lateral aspect. The mammary gland is embedded in subcutaneous fat, although fat is absent beneath the nipple and areola [1]. Mature resting breasts lie between the skin and the pectoralis major muscle, supported by Cooper's ligaments [3].
Question 112: Which is the primary muscle causing supination of the forearm?
- A. Brachioradialis
- B. Anconeus
- C. Biceps brachii
- D. Supinator (Correct Answer)
Explanation: ***Supinator*** - The **supinator muscle** is the **primary muscle** responsible for **supination** of the forearm, rotating the palm anteriorly or superiorly. - It is a deep muscle of the **posterior compartment** of the forearm. - Its action is especially prominent when **supinating against resistance** or in very slow movements, as it works synergistically with the biceps brachii. *Biceps brachii* - While the **biceps brachii** is also a powerful **supinator** of the forearm, especially when the elbow is flexed, it is a **secondary supinator**. - It is primarily a major **flexor** of the elbow, whereas the supinator is dedicated specifically to supination. *Brachioradialis* - The **brachioradialis** is primarily a **flexor** of the forearm at the elbow joint. - It helps to bring the forearm into a **mid-prone or mid-supine position** from either full pronation or full supination, but does not actively supinate. *Anconeus* - The **anconeus** is a small muscle that assists the **triceps brachii** in **extension of the forearm** at the elbow. - It helps to **stabilize the elbow joint** and slightly abducts the ulna during pronation, but has no role in supination.
Question 113: All are infraclavicular branches of brachial plexus except ?
- A. Axillary nerve
- B. Thoracodorsal nerve
- C. Long thoracic nerve (Correct Answer)
- D. Ulnar nerve
Explanation: Long thoracic nerve - The long thoracic nerve originates directly from the roots (C5, C6, C7) of the brachial plexus, making it a supraclavicular branch. - It does not arise from the cords of the brachial plexus, which are located infraclavicularly. Ulnar nerve - The ulnar nerve arises from the medial cord of the brachial plexus, which is an infraclavicular structure. - It supplies many intrinsic hand muscles and the ulnar half of the flexor digitorum profundus. Axillary nerve - The axillary nerve is a branch of the posterior cord of the brachial plexus, classifying it as an infraclavicular branch. - It innervates the deltoid and teres minor muscles. Thoracodorsal nerve - The thoracodorsal nerve also originates from the posterior cord of the brachial plexus, making it an infraclavicular branch [1]. - It provides motor innervation to the latissimus dorsi muscle [1].
Question 114: What is the largest branch of the brachial plexus?
- A. Ulnar nerve
- B. Radial nerve (Correct Answer)
- C. Axillary nerve
- D. Median nerve
Explanation: ***Radial nerve*** - The **radial nerve** is considered the largest branch of the brachial plexus due to its extensive innervation of numerous muscles in the posterior compartment of the arm and forearm. - It arises from the **posterior cord** of the brachial plexus and innervates all the extensors of the arm and forearm, including the triceps brachii and supinator. *Ulnar nerve* - The ulnar nerve is a significant branch, but it is **smaller** in cross-sectional area and muscular distribution compared to the radial nerve. - It mainly innervates muscles of the **hand** and some forearm flexors. *Median nerve* - The median nerve is a large and clinically important nerve, formed by contributions from both the **lateral and medial cords**, but it is generally *not* considered the largest in terms of overall bulk or number of muscular branches. - It primarily innervates the **flexor muscles of the forearm** and some muscles of the hand (thenar eminence). *Axillary nerve* - The axillary nerve is one of the **smaller** terminal branches of the brachial plexus. - It primarily innervates the **deltoid** and **teres minor muscles**, and a small area of skin over the shoulder.
Question 115: All are supplied by the anterior interosseous nerve except which of the following?
- A. Flexor carpi ulnaris (Correct Answer)
- B. Pronator quadratus
- C. Flexor digitorum profundus (lateral half)
- D. Flexor pollicis longus
Explanation: ***Flexor carpi ulnaris*** - The **flexor carpi ulnaris** (FCU) is innervated by the **ulnar nerve**, not the anterior interosseous nerve [1]. - This is the correct answer as it is NOT supplied by the AIN. *Pronator quadratus* - The **pronator quadratus** IS supplied by the **anterior interosseous nerve**. - This deep muscle is responsible for **pronation of the forearm** and is one of the three muscles innervated by the AIN. *Flexor digitorum profundus (lateral half)* - The **lateral half of flexor digitorum profundus** (to index and middle fingers) IS supplied by the **anterior interosseous nerve**. - The medial half (to ring and little fingers) is supplied by the ulnar nerve. *Flexor pollicis longus* - The **flexor pollicis longus** (FPL) IS supplied by the **anterior interosseous nerve**. - This muscle is responsible for **flexion of the thumb's interphalangeal joint** and is one of the three muscles innervated by the AIN.
Pathology
2 questionsWhich of the following statements is true regarding light microscopy findings in minimal change disease?
Which of the following is not a germ cell tumor?
NEET-PG 2013 - Pathology NEET-PG Practice Questions and MCQs
Question 111: Which of the following statements is true regarding light microscopy findings in minimal change disease?
- A. Foot process effacement is observed under electron microscopy, not light microscopy.
- B. Anti-GBM antibodies are associated with Goodpasture syndrome, not minimal change disease.
- C. No significant changes are seen under light microscopy. (Correct Answer)
- D. IgA deposits are characteristic of IgA nephropathy, not minimal change disease.
Explanation: ***No change seen*** - In minimal change disease, **light microscopy** typically shows no significant changes, which is a key characteristic of the condition [1]. - The disease primarily affects the **podocytes** leading to **nephrotic syndrome**, while light microscopy does not reveal any abnormalities [1]. *Loss of foot process seen* - Loss of foot processes is actually observed under **electron microscopy**, not light microscopy. - Light microscopy remains normal, differentiating minimal change disease from other glomerular diseases. *IgA deposits seen* - IgA deposits are associated with **IgA nephropathy**, which is a different condition characterized by mesangial deposition. - Minimal change disease does not have **immunofluorescence** findings, and thus shows no such deposits on light microscopy [1]. *Anti GBM Abs seen* - Anti-GBM antibodies are characteristic of **Goodpasture syndrome**, which presents with significant changes in glomerular structure. - In minimal change disease, there are no **anti-GBM antibodies** or major changes visible under light microscopy. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, pp. 927-928.
Question 112: Which of the following is not a germ cell tumor?
- A. Embryonal carcinoma
- B. Endodermal sinus
- C. Seminoma
- D. Leydig cell tumor (Correct Answer)
Explanation: ***Leydig cell tumor*** - Leydig cell tumors are classified as **sex-cord stromal tumors**, not germ cell tumors [1]. - These tumors are derived from **Leydig cells** which produce androgens, affecting the endocrine function rather than germ cell lineage [1]. *Endodermal sinus* - Endodermal sinus tumors, or **yolk sac tumors**, are indeed germ cell tumors characterized by **alpha-fetoprotein (AFP)** production [2]. - They typically arise in the testis or ovaries and are known for rapid growth and aggressiveness. *Embryonal carcinoma* - Embryonal carcinoma is a type of **germ cell tumor** commonly associated with elevated levels of **beta-hCG** [2]. - It primarily affects the testes in males and can occur in the ovaries, and it is known for its aggressive behavior. *Seminoma* - Seminomas are classic examples of **germ cell tumors**, noted for their sensitivity to radiation and chemotherapy [3]. - They usually present with **increased beta-hCG** levels and can coexist with non-seminomatous germ cell tumors [3]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Diseases Of The Urinary And Male Genital Tracts, pp. 510-514. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lower Urinary Tract and Male Genital System, pp. 979-980. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lower Urinary Tract and Male Genital System, pp. 980-982.
Pharmacology
3 questionsWhich beta-1 antagonist is used in congestive cardiac failure?
Which of the following is not a recognized use of alpha-2-agonists?
Which of the following is not a cardioselective beta blocker?
NEET-PG 2013 - Pharmacology NEET-PG Practice Questions and MCQs
Question 111: Which beta-1 antagonist is used in congestive cardiac failure?
- A. Atenolol
- B. Metoprolol (Correct Answer)
- C. Esmolol
- D. Bisoprolol
Explanation: ***Metoprolol*** - **Metoprolol succinate** (extended-release formulation) is a selective **beta-1 antagonist** proven to reduce mortality and hospitalizations in **chronic heart failure with reduced ejection fraction (HFrEF)**. - It works by **reducing heart rate, myocardial oxygen demand**, and preventing adverse cardiac remodeling through inhibition of chronic sympathetic activation. - Along with **bisoprolol and carvedilol**, it is one of the **three beta-blockers with proven mortality benefit** in heart failure trials. *Atenolol* - While atenolol is a selective beta-1 antagonist, it **lacks evidence for mortality benefit** in heart failure. - It has **high hydrophilicity** and renal elimination, leading to less favorable pharmacokinetics compared to metoprolol. - More commonly used for **hypertension and angina** rather than heart failure management. *Esmolol* - **Esmolol** is an ultra-short-acting selective beta-1 antagonist used for **acute control of heart rate** in perioperative and critical care settings. - Its **very short half-life (9 minutes)** makes it unsuitable for chronic management of heart failure. - Administered only **intravenously** and requires continuous infusion. *Bisoprolol* - While **bisoprolol is also approved** for heart failure and has proven mortality benefit (CIBIS-II trial), this question likely expects **metoprolol** as the answer given the historical context. - Both bisoprolol and metoprolol are acceptable answers, but **metoprolol** has been more widely studied and is more commonly cited in Indian medical exams. - Bisoprolol has **greater beta-1 selectivity** than metoprolol but similar clinical outcomes in heart failure.
Question 112: Which of the following is not a recognized use of alpha-2-agonists?
- A. Glaucoma
- B. Hypertension
- C. Sedation
- D. Benign Hyperplasia of prostate (Correct Answer)
Explanation: ***Correct Answer: Benign Hyperplasia of prostate*** - Alpha-2-agonists are **NOT** used to treat **benign prostatic hyperplasia (BPH)**; this condition is typically managed with **alpha-1-blockers** (e.g., tamsulosin, alfuzosin) or 5-alpha-reductase inhibitors. - Alpha-1-blockers relax the smooth muscle in the prostate and bladder neck, improving urine flow, which involves a different receptor mechanism than alpha-2-agonists. - Alpha-2-agonists would not provide therapeutic benefit for BPH. *Incorrect: Glaucoma* - Alpha-2-agonists (e.g., **brimonidine**, **apraclonidine**) **are** used to treat **glaucoma** by reducing aqueous humor production and increasing uveoscleral outflow. - This action helps to **lower intraocular pressure**, a primary goal in glaucoma management. *Incorrect: Hypertension* - Central-acting alpha-2-agonists (e.g., **clonidine**, **methyldopa**) **are** used as **antihypertensive agents**. - They reduce sympathetic outflow from the central nervous system, leading to decreased heart rate, vasodilation, and consequently, **lower blood pressure**. *Incorrect: Sedation* - Alpha-2-agonists like **dexmedetomidine** and **clonidine** **are** commonly used for **sedation** in critically ill patients, especially in intensive care units. - They produce sedation, analgesia, and anxiolysis without causing significant respiratory depression, making them valuable in certain clinical settings.
Question 113: Which of the following is not a cardioselective beta blocker?
- A. Nebivolol
- B. Atenolol
- C. Betaxolol
- D. Oxprenolol (Correct Answer)
Explanation: ***Oxprenolol*** - **Oxprenolol** is a non-selective beta-blocker with **intrinsic sympathomimetic activity (ISA)**, meaning it blocks both β1 and β2 receptors and partially stimulates them. - Its non-selective action means it affects both the heart (β1) and other organs like the lungs (β2), making it less suitable for patients with respiratory conditions. *Nebivolol* - **Nebivolol** is a highly cardioselective beta-blocker that primarily blocks **β1 receptors** and also has **vasodilatory properties** due to nitric oxide release. - Its high selectivity translates to fewer β2-mediated side effects, such as bronchoconstriction. *Atenolol* - **Atenolol** is a **cardioselective beta-blocker** that predominantly blocks **β1 receptors** at therapeutic doses. - This selectivity makes it a common choice for cardiovascular conditions, reducing the risk of bronchospasm compared to non-selective agents. *Betaxolol* - **Betaxolol** is a **cardioselective beta-blocker** primarily used for the treatment of hypertension and glaucoma. - It selectively blocks **β1 adrenergic receptors**, minimizing effects on the lungs compared to non-selective beta-blockers.