Anatomy
9 questionsAll are supplied by the anterior interosseous nerve except which of the following?
All are infraclavicular branches of brachial plexus except ?
What is the largest branch of the brachial plexus?
Which muscle will be paralyzed when the radial nerve is injured just below the spiral groove?
Which muscle receives a muscular branch from the ulnar nerve?
Which of the following statements about the mammary gland is false?
A person had injury to right upper limb, he is not able to extend fingers but able to extend wrist and elbow. Nerve injured is ?
All of the following muscles have dual nerve supply except which one?
Which of the following structures is not found in the midpalmar space?
NEET-PG 2013 - Anatomy NEET-PG Practice Questions and MCQs
Question 81: 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.
Question 82: 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 83: 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 84: Which muscle will be paralyzed when the radial nerve is injured just below the spiral groove?
- A. Extensor Digitorum
- B. Extensor Carpi Radialis Brevis (Correct Answer)
- C. Supinator
- D. Abductor Pollicis Longus
Explanation: Extensor Carpi Radialis Brevis - The radial nerve travels in the spiral groove of the humerus and gives off branches in a specific sequence. - Proximal to the spiral groove: Branches to triceps and anconeus - Within/at the spiral groove: Branches to brachioradialis and extensor carpi radialis longus (ECRL) - Just distal to the spiral groove: Branch to extensor carpi radialis brevis (ECRB) [1] - this is the first branch after exiting the spiral groove - More distally: The nerve divides into superficial and deep branches (posterior interosseous nerve) [1] - An injury just below the spiral groove would paralyze ECRB while sparing muscles innervated proximal to or within the groove (triceps, anconeus, brachioradialis, ECRL). Supinator - The supinator is innervated by the deep branch of the radial nerve (posterior interosseous nerve), which branches off more distally in the proximal forearm. - This muscle would only be affected by injuries distal to the bifurcation of the radial nerve into superficial and deep branches, not by an injury just below the spiral groove. Extensor Digitorum - The extensor digitorum is supplied by the posterior interosseous nerve, which is a continuation of the deep branch [1]. - This innervation occurs significantly distal to the spiral groove in the posterior forearm compartment. - It would be affected by posterior interosseous nerve injuries, not by lesions just below the spiral groove. Abductor Pollicis Longus - The abductor pollicis longus is innervated by the posterior interosseous nerve in the distal forearm [1]. - This is the most distal of all the options and would only be affected by posterior interosseous nerve palsy, not by radial nerve injury at the spiral groove level [1].
Question 85: Which muscle receives a muscular branch from the ulnar nerve?
- A. Both FCU and FDP (Correct Answer)
- B. FCU
- C. None of the options
- D. FDP
Explanation: ***Both FCU and FDP*** - The **flexor carpi ulnaris (FCU)** is solely innervated by the **ulnar nerve** in the forearm. - The **flexor digitorum profundus (FDP)** has dual innervation: the **ulnar nerve** supplies the medial half (tendons to ring and little fingers), while the anterior interosseous nerve (branch of median nerve) supplies the lateral half (tendons to index and middle fingers). - Both muscles receive muscular branches from the ulnar nerve, making this the most complete and accurate answer. *FCU* - While the FCU does receive innervation from the ulnar nerve (and only the ulnar nerve), this option is incorrect because the FDP also receives branches from the ulnar nerve. - Selecting only FCU ignores the dual innervation of FDP and is therefore an incomplete answer when "Both FCU and FDP" is available. *FDP* - While the medial half of FDP does receive innervation from the ulnar nerve, this option is incorrect because FCU also receives innervation from the ulnar nerve. - Selecting only FDP ignores the complete innervation of FCU and is therefore an incomplete answer when "Both FCU and FDP" is available. *None of the options* - This option is incorrect because both the **flexor carpi ulnaris** and the medial portion of the **flexor digitorum profundus** definitively receive muscular branches from the ulnar nerve. - The ulnar nerve provides motor innervation to these specific forearm muscles before continuing into the hand.
Question 86: 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 87: A person had injury to right upper limb, he is not able to extend fingers but able to extend wrist and elbow. Nerve injured is ?
- A. Median
- B. Ulnar
- C. Radial
- D. Posterior interosseous (Correct Answer)
Explanation: ***Posterior interosseous*** - This nerve supplies the muscles responsible for **finger extension**, such as the **extensor digitorum**, **extensor indicis**, and **extensor digiti minimi**. - A lesion here would spare wrist and elbow extension because the nerves to the **extensor carpi radialis longus/brevis** and **triceps brachii** branch off the radial nerve proximal to the origin of the posterior interosseous nerve. *Radial* - A more proximal **radial nerve injury** would result in the inability to extend the wrist (leading to **wrist drop**), fingers, and thumb, which is not seen here as wrist extension is preserved. - It also innervates the **triceps brachii**, and a high radial nerve injury would affect elbow extension; this patient can extend their elbow. *Median* - The **median nerve** primarily innervates muscles responsible for **flexion** of the wrist and fingers, as well as **thumb opposition** and **pronation**. - Its injury would not directly lead to an inability to extend the fingers, but rather weakness in flexion and specific thumb movements. *Ulnar* - The **ulnar nerve** innervates most of the **intrinsic hand muscles** and the **flexor carpi ulnaris**, leading to weakness in finger abduction/adduction and flexion of the 4th and 5th digits. - It does not control finger extension, so an injury would not cause this specific deficit.
Question 88: All of the following muscles have dual nerve supply except which one?
- A. Pectoralis major
- B. Flexor digitorum profundus
- C. Biceps brachii (Correct Answer)
- D. Subscapularis
Explanation: ***Biceps brachii*** - The **biceps brachii** muscle is solely innervated by the **musculocutaneous nerve (C5, C6, C7)**. - This muscle is a prime mover for forearm supination and elbow flexion and does not receive nerve supply from any other nerve. *Subscapularis* - The **subscapularis** muscle has a dual nerve supply from both the **upper and lower subscapular nerves (C5, C6)**. - This dual innervation ensures motor control of the subscapularis, which is an important medial rotator of the humerus. *Pectoralis major* - The **pectoralis major** muscle receives a dual nerve supply from both the **medial and lateral pectoral nerves** [1]. - The **lateral pectoral nerve** primarily supplies the clavicular head, while the **medial pectoral nerve** supplies both the sternocostal head and a portion of the clavicular head [1]. *Flexor digitorum profundus* - The **flexor digitorum profundus** muscle has a dual nerve supply from the **median nerve** (innervating the lateral half for digits 2 and 3) and the **ulnar nerve** (innervating the medial half for digits 4 and 5). - This dual innervation allows for independent or coordinated flexion of the distal phalanges of the fingers.
Question 89: Which of the following structures is not found in the midpalmar space?
- A. 2nd lumbrical
- B. 1st lumbrical (Correct Answer)
- C. FDP of 4th finger
- D. FDP of 3rd finger
Explanation: ***1st lumbrical*** - The **1st lumbrical** is typically found within the **thenar space** or the **central compartment of the palm**, not the midpalmar space [1]. - Its position is associated with the **index finger's flexor tendons**, which do not traverse the midpalmar space. *2nd lumbrical* - The **2nd lumbrical** is located in the **midpalmar space**, situated on the radial side of the **flexor digitorum profundus (FDP) tendon** to the third digit [1]. - It arises from the radial side of the **FDP tendon** of the **middle finger** [1]. *FDP of 3rd finger* - The **flexor digitorum profundus (FDP) tendon** to the **third finger** (middle finger) passes through the **midpalmar space** [1]. - These tendons, along with their associated lumbricals, are key components of the **midpalmar space**. *FDP of 4th finger* - The **flexor digitorum profundus (FDP) tendon** to the **fourth finger** (ring finger) also travels through the **midpalmar space** [1]. - The midpalmar space contains the **FDP tendons** for the middle, ring, and little fingers, as well as their corresponding lumbricals (2nd, 3rd, and 4th).
Pathology
1 questionsWhich of the following statements is true regarding light microscopy findings in minimal change disease?
NEET-PG 2013 - Pathology NEET-PG Practice Questions and MCQs
Question 81: 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.