NEET-PG 2013 - Anatomy Practice Questions

Q: Sacrotuberous ligament is pierced by

Perforating cutaneous nerve. ***Perforating cutaneous nerve*** - The **perforating cutaneous nerve** typically pierces the sacrotuberous ligament to innervate the skin over the medial part of the lower gluteal region. - This nerve originates from the **S2 and S3 anterior rami**. *Posterior femoral cutaneous* - The **posterior femoral cutaneous nerve** runs inferior to the piriformis muscle, superficial to the sacrotuberous ligament, but does not pierce it. - It supplies the skin on the posterior thigh and popliteal fossa. *Superior gluteal nerve* - The **superior gluteal nerve** exits the pelvis through the greater sciatic foramen, superior to the piriformis muscle, and does not interact with the sacrotuberous ligament in this manner. - It innervates the **gluteus medius, gluteus minimus**, and **tensor fasciae latae muscles**. *Sciatic nerve* - The **sciatic nerve** exits the pelvis via the greater sciatic foramen, inferior to the piriformis muscle, and passes superficial to the sacrotuberous ligament. - It does not pierce the ligament, but rather lies in close proximity to its inferior border.

Q: Which muscle will be paralyzed when the radial nerve is injured just below the spiral groove?

Extensor Carpi Radialis Brevis. 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].

Q: Which muscle receives a muscular branch from the ulnar nerve?

Both FCU and FDP. ***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.

Q: All of the following muscles have dual nerve supply except which one?

Biceps brachii. ***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.

Q: All are infraclavicular branches of brachial plexus except ?

Long thoracic nerve. 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].

Q: What is the largest branch of the brachial plexus?

Radial nerve. ***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.

Q: 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 ?

Posterior interosseous. ***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.

Q: How many ossification centers develop at the distal end of the humerus?

3. ***3*** - The distal end of the humerus develops **three primary ossification centers**: the capitellum, trochlea, and medial epicondyle [1]. - These centers appear sequentially and their ossification pattern is important for assessing **skeletal maturity** in children using the CRITOE mnemonic [1]. - The capitellum appears at 1 year, medial epicondyle at 5 years, and trochlea at 9 years. *2* - This number is too low and only accounts for the **capitellum and medial epicondyle**, missing the trochlea. - While these are the first two to appear, there is an additional primary ossification center (trochlea) that develops later. *5* - This number is incorrect; there are only **three primary ossification centers** at the distal humerus, not five. - This may cause confusion with other joints or by counting secondary ossification centers. *4* - This number is incorrect; while the lateral epicondyle does ossify, it is not consistently counted as a **primary ossification center**. - The standard anatomical teaching recognizes **three primary centers**: capitellum, trochlea, and medial epicondyle.

Q: Which muscle is attached to the lateral surface of the greater trochanter?

Gluteus medius. ***Gluteus medius*** - The **gluteus medius** inserts onto the **lateral surface of the greater trochanter** of the femur. - Its primary actions include **abduction** and **internal rotation** of the hip. *Gluteus maximus* - The **gluteus maximus** inserts primarily into the **iliotibial tract** and the **gluteal tuberosity** of the posterior femur, not the lateral greater trochanter. - Its main roles are **hip extension** and **external rotation**. *Gluteus minimus* - The **gluteus minimus** inserts onto the **anterior part of the lateral surface (anterolateral aspect)** of the greater trochanter, anterior to the gluteus medius insertion. - Like the gluteus medius, it also contributes to **hip abduction** and **internal rotation**. *Piriformis* - The **piriformis** muscle inserts onto the **superior and medial aspect of the greater trochanter**. - Its main actions are **external rotation** and **abduction** of the hip, particularly when the hip is flexed.

Q: Line from midinguinal point to adductor tubercle represents?

Femoral artery. The line from the **midinguinal point** to the **adductor tubercle** accurately maps the anatomical course of the **femoral artery** in the thigh. This anatomical landmark is crucial for palpating the **femoral pulse** and locating the artery for clinical procedures like catheter insertion. *Inferior epigastric artery* - The **inferior epigastric artery** originates from the external iliac artery and ascends superiorly in the anterior abdominal wall [1]. - Its course is significantly more medial and superior, far from the line described. *Superior epigastric artery* - The **superior epigastric artery** is a terminal branch of the internal thoracic artery, descending into the rectus sheath in the upper abdomen [1]. - Its location is entirely within the anterior abdominal wall, high above the inguinal region. *None of the options* - This option is incorrect because the line from the midinguinal point to the adductor tubercle clearly represents the anatomical course of the femoral artery. - The other arteries listed are not found along this specific anatomical path.

Question 1

Sacrotuberous ligament is pierced by

Accepted Answer

Perforating cutaneous nerve

Answer

Posterior femoral cutaneous nerve

Answer

Superior gluteal nerve

Answer

Sciatic nerve

Question 2

Which muscle will be paralyzed when the radial nerve is injured just below the spiral groove?

Accepted Answer

Extensor Carpi Radialis Brevis

Answer

Extensor Digitorum

Answer

Supinator

Answer

Abductor Pollicis Longus

Question 3

Which muscle receives a muscular branch from the ulnar nerve?

Accepted Answer

Both FCU and FDP

Answer

FCU

Answer

None of the options

Answer

FDP

Question 4

All of the following muscles have dual nerve supply except which one?

Accepted Answer

Biceps brachii

Answer

Pectoralis major

Answer

Flexor digitorum profundus

Answer

Subscapularis

Question 5

All are infraclavicular branches of brachial plexus except ?

Accepted Answer

Long thoracic nerve

Answer

Axillary nerve

Answer

Thoracodorsal nerve

Answer

Ulnar nerve

Question 6

What is the largest branch of the brachial plexus?

Accepted Answer

Radial nerve

Answer

Ulnar nerve

Answer

Axillary nerve

Answer

Median nerve

Question 7

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 ?

Accepted Answer

Posterior interosseous

Answer

Median

Answer

Ulnar

Answer

Radial

Question 8

How many ossification centers develop at the distal end of the humerus?

Accepted Answer

3

Answer

2

Answer

5

Answer

4

Question 9

Which muscle is attached to the lateral surface of the greater trochanter?

Accepted Answer

Gluteus medius

Answer

Gluteus maximus

Answer

Gluteus minimus

Answer

Piriformis

Question 10

Line from midinguinal point to adductor tubercle represents?

Accepted Answer

Femoral artery

Answer

Inferior epigastric artery

Answer

Superior epigastric artery

Answer

None of the options

NEET-PG 2013 — Anatomy