Anatomy/Kines Questions (Netters)

A 34-year-old homemaker presents with pain over her dorsal wrist and the styloid process of the radius, probably as a result of repetitive movements. The pain is exacerbated by flexing the thumb and then placing the wrist in ulnar deviation (adduction of the wrist). Inflammation of which of the following muscle groups and their tendinous sheaths is most likely the cause of this condition? A. Abductor pollicis longus and extensor pollicis brevis B. Extensor carpi radialis longus and brevis C. Extensor digitorum and extensor indicis D. Extensor pollicis longus E. Flexor pollicis longus and brevis

A. Abductor pollicis longus and extensor pollicis brevis The tendons of the abductor pollicis longus and extensor pollicis brevis muscles pass through the same tendon sheath on the dorsum of the wrist. Repetitive movements (gripping or a twisting-wringing action) can lead to pain over the styloid process of the radius

Dislocation of the shoulder places this nerve in jeopardy of injury. A. Axillary B. Dorsal scapular C. Long thoracic D. Musculocutaneous E. Radial F. Suprascapular

A. Axillary The axillary nerve (innervates the deltoid and teres minor muscles) can be injured by shoulder dislocations. This nerve passes through the quadrangular space before innervating its two muscles.

This muscle generally may not be the strongest flexor of the forearm at the elbow, but it is the strongest supinator of the hand. A. Biceps brachii B. Brachialis C. Brachioradialis D. Supinator

A. Biceps brachii The biceps brachii muscle flexes the forearm at the elbow. It also is the "power supinator" when the elbow is flexed, but it does not supinate when the elbow is extended.

This muscle's tendon has the highest rate of spontaneous rupture of any muscle tendon in the body! A. Biceps brachii B. Brachialis C. Brachioradialis E. Flexor digitorum superficialis F. Pronator teres

A. Biceps brachii The biceps brachii tendon has the highest rate of spontaneous rupture of any muscle tendon in the body. Rupture of the long head of the biceps brachii tendon is the most common

A wrestler comes off the mat holding his right forearm flexed at the elbow and pronated, with his shoulder medially rotated and displaced inferiorly. Which of his bones is most likely broken? A. Clavicle B. Humerus C. Radius D. Scapula E. Ulna

A. Clavicle Fractures of the clavicle are relatively common and occur most often in the middle third of the bone. The distal fragment is displaced downward by the weight of the shoulder and drawn medially by the action of the pectoralis major, teres major, and latissimus dorsi muscles.

A fall on an outstretched hand results in swelling and pain on the lateral aspect of the wrist. Radiographic examination confirms a Colles' fracture. Which of the following bones is most likely fractured? A. Distal radius B. Distal ulna C. Lunate D. Scaphoid E. Trapezium

A. Distal Radius The Colles' fracture (a fracture of the distal radius) presents with a classic dinner fork deformity with the dorsal and proximal displacement of the distal fragment. This is an extension-compression fracture.

An elderly woman falls on her outstretched hand and fractures the surgical neck of her humerus. Several weeks later she presents with significant weakness in abduction of her arm and some weakened extension and flexion at the shoulder. Which of the following nerves is most likely injured? A. Accessory B. Axillary C. Radial D. Subscapular E. Thoracodorsal

B. Axillary Fractures of this portion of the humerus can place the axillary nerve in danger of injury. Her muscle weakness confirms that the deltoid muscle especially is weakened, and the deltoid and teres minor muscles are innervated by the axillary nerve.

During a routine physical examination, the physician notes an absent biceps tendon reflex. Which spinal cord level is associated with this tendon reflex? A. C4-C5 B. C5-C6 C. C6-C7 D. C7-C8 E. C8-T1

B. C5-C6 The biceps tendon reflex tests the musculocutaneous nerve and especially the C5-C6 contribution. The triceps tendon reflex tests the C7-C8 spinal contributions of the radial nerve.

The tendon of this muscle may be used as a guide to find and take a radial artery pulse. A. Flexor digitorum superficialis B. Flexor carpi radialis C. Flexor pollicis longus D. Palmaris longus

B. Flexor carpi radialis Making a slight fist will cause the flexor tendons of the wrist to become prominent under the skin. The tendon of the flexor carpi radialis muscle can then be used to locate the radial artery, which lies just lateral to this tendon. Be sure to feel the pulse with your index and/or middle finger, and not your thumb. If you use your thumb, you may be sensing you own pulse and not that of your patient!

Angina pectoris leads to referred pain, which radiates down the arm. What nerve is responsible for this? A. Axillary B. Medial brachial cutaneous C. Medial antebrachial cutaneous D. Musculocutaneous E. Radial F. Ulnar

B. Medial brachial cutaneous Referred pain from myocardial ischemia can be present along the medial aspect of the arm, usually on the left side, and is referred to this area by the medial brachial cutaneous nerve (T1). The intercostal brachial nerve (T2) may also contribute to this sensation.

This is the deepest muscle in the forearm anterior muscle compartment innervated by the median nerve. A. Flexor pollicis longus B. Pronator quadratus C. Pronator teres D. Supinator

B. Pronator quadratus The pronator quadratus muscle extends between the distal ulna and radius, is innervated by the median nerve, and is the deepest of the anterior compartment muscles of the forearm. It pronates the forearm and hand.

A pulse may be taken at several locations on the upper limb. One such location is in the anatomical snuffbox, between the extensor pollicis brevis and longus tendons; at this location one may palpate the radial artery. In taking this pulse, the artery is pressed against which of the following bones? A. Capitate bone B. Scaphoid bone C. Trapezium bone D. Trapezoid bone E. Triquetrum bone

B. Scaphoid bone The radial pulse in the anatomical snuffbox may be palpated by pressing the artery against the underlying scaphoid tarsal. Most arterial pulses are felt by pressing the artery against an underlying bony structure.

Although innervated by the radial nerve, this muscle is actually a flexor of the forearm at the elbow. A. Biceps brachii B. Brachialis C. Brachioradialis D. Flexor carpi radialis E. Flexor carpi ulnaris F. Flexor digitorum superficialis G. Flexor pollicis longus H. Palmaris longus I. Pronator quadratus J. Pronator teres K. Supinator

C. Brachioradialis The brachioradialis muscle lies on the margin between the anterior and posterior compartment muscles of the forearm; it is considered along with the extensor/supinator muscles of the posterior compartment and is hence innervated by the radial nerve. It flexes the forearm at the elbow, especially when the forearm is in midpronation.

During your introductory course to clinical medicine, you are asked to take the radial pulse of your classmate. Which of the following muscle tendons can you use as a guide to locate the radial artery? A. Adductor pollicis longus B. Brachioradialis C. Flexor carpi radialis D. Flexor pollicis longus E. Palmaris longus

C. Flexor carpi radialis The radial pulse can be easily taken at the wrist where the radial artery lies just lateral to the tendon of the flexor carpi radialis muscle.

Which of the following tendons is most vulnerable to inflammation and sepsis in the shoulder joint? A. Glenoid labrum B. Infraspinatus C. Long head of biceps D. Long head of triceps E. Supraspinatus

C. Long head of biceps The long head of the biceps tendon passes through the shoulder joint and attaches to the supraglenoid tubercle of the scapula. An infection in the joint could involve this tendon.

Despite injury to the radial nerve in the arm, a patient is still capable of supination of the forearm. What nerve allows for this? A. Axillary B. Median C. Musculocutaneous D. Radial E. Ulnar

C. Musculocutaneous While the supinator muscle is denervated (loss of radial nerve), the biceps brachii muscle is innervated by the musculocutaneous nerve and is a powerful supinator when the elbow is flexed.

A baseball pitcher delivers a 97-mph fastball to a batter and suddenly feels a sharp pain in his shoulder on release of the ball. The trainer examines the shoulder and concludes that the pitcher has a rotator cuff injury. Which muscle is most vulnerable and most likely torn by this type of injury? A. Infraspinatus B. Subscapularis C. Supraspinatus D. Teres major E. Teres minor

C. Supraspinatus The supraspinatus muscle is most often torn in rotator cuff injuries. Repeated abduction and flexion can cause the tendon to rub on the acromion and coracoacromial ligament, leading to tears or rupture.

Which of the following muscle-nerve combinations is tested when spreading the fingers against resistance? A. Abductor digiti minimi muscle and median nerve B. Abductor pollicis brevis muscle and radial nerve C. Abductor pollicis longus muscle and median nerve D. Dorsal interossei muscle and ulnar nerve E. Palmar interossei muscle and ulnar nerve

D. Dorsal interossei muscle and ulnar nerve The dorsal interossei are innervated by the ulnar nerve and abduct the fingers (the little finger and thumb have their own abductors). This action is easily tested in a patient; dorsal interossei abduct the fingers (DAB) and palmar interossei adduct the fingers (PAD).

When asked to make a fist, the patient is unable to flex the first three fingers into the palm, and the fourth and fifth fingers are partially flexed at the MCP and DIP joints. What nerve could be damaged? A. Axillary B. Medial brachial cutaneous C. Medial antebrachial cutaneous D. Median E. Radial F. Ulnar

D. Median This suggests a lesion to the median nerve. The thenar muscles are affected, as are the long flexors of the digits (flexor digitorum superficialis muscle and profundus muscle to the index and middle fingers). Unopposed extension of the first three fingers occurs, and absence of flexion at the PIP joints of fingers 4 and 5 is evident. The thumb is adducted against the index finger. The position of the hand is that of a "papal" or "benediction" sign.

A patient with a midshaft compound humeral fracture presents with bleeding and clinical signs of nerve entrapment. Which of the following nerves is most likely injured by the fracture? A. Axillary B. Median C. Musculocutaneous D. Radial E. Ulnar

D. Radial The radial nerve spirals around the posterior aspect of the midhumeral shaft and can be stretched or contused by a compound fracture of the humerus. This nerve innervates all the extensor muscles of the upper limb (posterior compartments of the arm and forearm).

A football player has a dislocated shoulder. The trainer is able to reduce the dislocation, but the player still has significant pain over his dorsal shoulder and cannot abduct his arm in a normal manner. Which of the following muscles has most likely been injured by the dislocation? A. Coracobrachialis muscle B. Long head of the biceps muscle C. Long head of the triceps muscle D. Supraspinatus muscle E. Teres major muscle

D. Supraspinatus muscle The supraspinatus muscle is often injured by shoulder dislocation, which usually occurs in an anteroinferior direction. The supraspinatus muscle is critical for initiating the first 15 degrees of abduction at the shoulder before the deltoid muscle takes over.

The most common type of shoulder dislocation is... (Part of a diagram -- just making this a normal question)

Dislocation of the head of the humerus often happens in an anterior and slightly inferior direction, with the head coming to lie just beneath the coracoid process (a subcoracoid dislocation). When this happens, the axillary and/or musculocutaneous nerves may be injured.

A fracture of the first rib appears to have damaged the inferior trunk of the brachial plexus where it crosses the rib. Which of the following spinal nerve levels would most likely be affected by this injury? A. C4-C5 B. C5-C6 C. C6-C7 D. C7-C8 E. C8-T1

E. C8-T1 The inferior trunk of the plexus crosses over the first rib, where it is vulnerable to injury. It arises from the C8 and T1 anterior rami of the spinal nerves.

The two heads of this muscle can compress the median nerve in the proximal forearm. A. Biceps brachii B. Brachialis C. Brachioradialis D. Flexor digitorum superficialis E. Pronator teres

E. Pronator teres The median nerve passes beneath the bicipital aponeurosis and then between the humeral and ulnar heads of the pronator teres muscle. This is the second most common site for median nerve compression after carpal tunnel compression at the wrist.

A football player has a complete fracture of his radius just proximal to the insertion of the pronator teres muscle. As a result of the actions of the muscles attached to the proximal and distal fragments of the radius, which of the following combinations accurately reflects the orientation of the proximal and distal radial fragments? A. Proximal extended, and distal pronated B. Proximal extended and pronated, and distal supinated C. Proximal flexed, and distal pronated D. Proximal flexed, and distal supinated E. Proximal flexed and supinated, and distal pronated

E. Proximal flexed and supinated, and distal pronated The proximal fragment will be flexed and supinated by the biceps brachii and supinator muscles, while the distal fragment will be pronated by the action of the pronator teres and pronator quadratus muscles.

A fracture of the clavicle results in some internal bleeding. Which of the following vessels is most likely the cause of the bleeding? A. Axillary vein B. Cephalic vein C. Internal jugular vein D. Internal thoracic vein E. Subclavian vein

E. Subclavian vein The most superficial of the listed structures to the clavicle is the subclavian vein, which passes between it and the first rib. The other vessels do not have this relationship. The subclavian artery also parallels the vein but lies on a deeper plane and is not one of the choices.

An 81-year-old man presents with pain in his shoulder; it is especially acute upon abduction. Further examination reveals intramuscular inflammation that has spread over the head of the humerus. Which of the following structures is most likely inflamed? A. Biceps brachii tendon (long head) B. Glenoid cavity C. Glenoid labrum D. Infraspinatus muscle E. Subdeltoid bursa

E. Subdeltoid bursa The subdeltoid bursa lies between the underlying supraspinatus tendon and the deltoid muscle, both of which are involved in abduction at the shoulder. Inflammation of these muscle tendons (neither is listed as an option) and the secondary inflammation of subdeltoid bursa is common

Following an assembly line worker's complaint of tingling pain in her wrist with muscle weakness and atrophy, her physician makes a diagnosis of carpal tunnel syndrome. Which of the following muscles is most likely to be atrophied? A. Adductor pollicis B. Dorsal interossei C. Flexor digitorum superficialis D. Lumbricals 3 and 4 E. Thenar

E. Thena The thenar muscles are located at the base of the thumb and are innervated by the median nerve, which passes through the carpal tunnel and is prone to injury in excessive repetitive movements at the wrist.

A patient presents with numbness over his medial hand and atrophy of the hypothenar muscles after an injury several days ago over his medial humeral epicondyle. Which of the following nerves most likely was injured? A. Anterior interosseous B. Musculocutaneous C. Recurrent branch of median D. Superficial radial E. Ulnar

E. Ulnar The ulnar nerve is subcutaneous as it passes around the medial epicondyle of the humerus. In this location, it is vulnerable to compression injury against the bone ("funny bone") or entrapment in the cubital tunnel (beneath the ulnar collateral ligament).

Cubital tunnel syndrome is the second most common compression neuropathy after carpal tunnel syndrome. Cubital tunnel syndrome occurs as which of the following nerves passes deep to a ligament and between the two heads of one of the flexor muscles of the wrist? A. Axillary nerve B. Median nerve C. Musculocutaneous nerve D. Radial nerve E. Ulnar nerve

E. Ulnar nerve The ulnar nerve passes under the ulnar collateral ligament at the elbow and then between the two heads of the flexor carpi ulnaris muscle. This injury is referred to as cubital tunnel syndrome and is not uncommon.

A knife cut results in a horizontal laceration to the thoracic wall extending across the midaxillary and anterior axillary lines just above the level of the T4 dermatome. Which of the following patient presentations will the emergency department physician most likely observe on examining the patient? A. Tingling along anterolateral forearm B. Supinated forearm C. Weakened elbow extension D. Weakened elbow flexion E. Winged scapula

E. Winged scapula This laceration probably severed the long thoracic nerve, which innervates the serratus anterior muscle. During muscle testing, the scapula will "wing" outwardly if this muscle is denervated.

Following a difficult forceps delivery, a newborn infant is examined by her pediatrician, who notes that her right upper limb is adducted and internally rotated. Which of the following components of her brachial plexus was most likely injured during the difficult delivery? A. Lateral cord B. Medial cord C. Posterior cord D. Roots of inferior trunk E. Roots of middle trunk F. Roots of superior trunk

F. Roots of the superior trunk Tension of the upper portion of the brachial plexus, specifically the superior trunk, can be injured by a forceps delivery. The adducted and internally rotated limb suggests an injury to the C5-C6 spinal roots known as Erb's palsy or Erb-Duchenne paralysis. Abduction, lateral rotation, and flexion of the arm may be weakened or lost.

What nerve is most likely responsible for claw hand? A. Axillary B. Medial brachial cutaneous C. Medial antebrachial cutaneous D. Median E. Radial F. Ulnar

F. Ulnar "Claw hand" is a typical deformity of the ulnar nerve. The last two digits may be hyper-extended at the MCP joint (because of the unopposed action of the extensor digitorum muscle, which is innervated by the radial nerve), flexed at the PIP joint (because of the action of the flexor digitorum superficialis muscle, which is innervated by the median nerve), and extended at the DIP joint (because of the loss of action by the flexor digitorum profundus muscle, which is innervated by the ulnar nerve, and the action of the unopposed extensor expansion).

This bone is one of the first to begin to ossify (by intramembranous ossification), but it is usually the last one to fuse, at some time in the third decade of life. (Part of a diagram -- just making this a normal question)

The clavicle is a bit unusual because it ossifies by intramembranous ossification, is one of the first bones to ossify, and is one of the last bones to fuse. All of the other bones of the appendicular skeleton ossify by endochondral bone formation.

Just above this bony feature lies the muscle that initiates abduction at the shoulder. What is the bony feature? What muscle initiates shoulder abduction? (Part of a diagram -- just making this a normal question)

The spine of the scapula separates the infraspinous and supraspinous fossae. The supraspinatus muscle lies superior to the spine and initiates abduction of the arm at the shoulder.