Anatomy Block 1 Practice Questions- Upper Limb, Back, Etc.

This is a/an horizontal/axial MR image of a normal shoulder. The arrow points to the: A.greater tuberosity (tubercle) of the humerus. B.lesser tuberosity (tubercle) of the humerus. C.intertubercular sulcus. D.glenoid fossa (cavity). E.coracoid process.

B.lesser tuberosity (tubercle) of the humerus. The arrow is pointing to a structure on the anterior surface of the head of the humerus. It is the lesser tuberosity since it is medial to the intertubercular sulcus. The greater tuberosity is lateral to the sulcus. The glenoid fossa (or cavity) is the depression on the scapula at the site of the glenohumeral joint. This is medial and posterior to the arrow. The coracoid process of the scapula is not seen in this image.

Two muscles that medially (internally) rotate the glenohumeral joint are the: A.infraspinatus and subscapularis. B.subscapularis and pectoralis major. C.latissimus dorsi and infraspinatus. D.teres minor and teres major.

B.subscapularis and pectoralis major. The pectoralis major, subscapularis, latissimus dorsi and teres major all attach to anteriorly to the humerus and therefore medially (internally) rotate at the glenohumeral joint. The infraspinatus and teres minor attach posteriorly to the humerus and laterally (externally) rotate at the glenohumeral joint.

A subject cuts his wrist and severs the tendon of the brachioradialis muscle along with a cutaneous nerve that crosses the tendon. He has diminished sensation in an area that includes part of the thenar eminence and the dorsal surface of the thumb. The insensitive area is a part of dermatome __________ that developmentally was part of the __________ border of the embryo. A.C6 --- preaxial B.C6 --- postaxial C.C7 --- preaxial D.C7 --- postaxial

C6 --- preaxial The superficial radial nerve is located just medial to the brachioradialis tendon at the wrist. This nerve innervates parts of dermatomes 6, 7 and 8 but the area described as insensitive (part of the thenar eminence and the dorsal surface of the thumb) is within dermatome 6. The preaxial border of the embryo includes dermatome C6.

The skin of the distal part of the medial forearm is numb. This may indicate herniation of the intervertebral disc between vertebrae A.C5 and C6 B.C6 and C7 C.C7 and T1 D.T1 and T2

C7 and T1 The medial forearm is the territory of dermatome C8. Spinal nerve C8 emerges between vertebrae C7 and T1 and herniation of the intervertebral disc between these vertebrae would impinge upon it.

The intervertebral foramen between vertebrae L3 and L4 contains spinal nerve _____. The segment of spinal cord giving rise to this nerve is __________ to this intervertebral foramen. A.L3 --- superior B.L3 --- adjacent C.L3 --- inferior D.L4 --- superior E.L4 --- adjacent F.L4 --- inferior

L3 --- superior Lumbar spinal nerves emerge inferior to the vertebra with the same number. Therefore the spinal nerve between vertebrae L3 and L4 will be spinal nerve L3. Due to differential growth during development, the spinal cord is shorter than the vertebral column and the lumbar spinal cord segments are superior to the lumbar vertebrae.

The muscle labeled "3" is innervated by the __________ nerve. A.long thoracic B.lower subscapular C.medial pectoral D.lateral pectoral

Muscle "3" is the serratus anterior, innervated by the long thoracic nerve. The lower subscapular nerve innervates the subscapularis (muscle "4") and teres major (not numbered). The medial pectoral nerve innervates the sternocostal head of the pectoralis major (muscle "2") and the pectoralis minor (muscle "1"). The lateral pectoral nerve innervates the clavicular head of the pectoralis major (not visible in this plane of section).

The muscle labeled _____ has an attachment to the lesser tuberosity of the humerus. A."1" B."2" C."3" D."4"

Muscle "4" is the subscapularis that attaches to the lesser tuberosity of the humerus and subscapular fossa. Muscles "1" (pectoralis minor) and "3" (serratus anterior) do not attach to the humerus. Muscle "2" (pectoralis major) attaches to the intertubercular groove of the humerus.

A patient arrives at the emergency room bleeding profusely and screaming that he has been stabbed in the shoulder. Pressure is applied to the wound and the bleeding is brought under control. You suspect that the knife cut may have resulted in nerve damage. Flexion, extension, abduction and adduction at the glenohumeral joint are normal. Extension at the elbow joint and pronation are also normal, however, flexion at the elbow joint is greatly weakened while supination is somewhat weakened. You continue your exam by determining whether there are any other motor deficits and find that movements at the wrist joints are normal, as are movements of the fingers. Using an open safety pin, you also determine that there is a loss of sensation on the lateral surface of the forearm. All other cutaneous innervation of the upper limb is normal. From the diagram below, choose the most likely position for the nerve lesion.

This patient exhibits weakness in flexion at the elbow joint and compromised supination. In addition, there is a loss of sensation over the lateral surface of forearm. This sensory deficit indicates damage to the lateral antebrachial cutaneous nerve, the terminal part of musculocutaneous nerve. Thus only A (musculocutaneous) or B (lateral cord) can be correct. If B (the lateral cord,) was cut, the median nerve would also be affected and the patient would exhibit weakened pronation (pronator teres, pronator quadratus), opposition of thumb (opponens pollicis via recurrent branch of median n.) and movement of the fingers at the interphalangeal joints. These movements are all normal. Flexion at the elbow joint is greatly weakened and damage to either A (musculocutaneous) or B (lateral cord) would affect the brachialis and biceps brachii, flexors at the elbow. Flexion is not lost since the brachioradialis is still innervated by the radial nerve however the pronator teres would be affected if B were cut. Supination is somewhat weakened because the biceps supinates. The supinator is unaffected since the deep radial nerve innervates it.

____________ a prominent characteristic of all cervical vertebrae. A.Costal facets are B.A large, massive vertebral body is C.Transverse foramina (foramina transversaria) are D.A long spinous process is

Transverse foramina (foramina transversaria) are The transverse foramina are a characteristic feature of all cervical vertebrae. A long spinous process is characteristic of vertebra C7 but not all cervical vertebrae. Costal facets are where the ribs articulate and are characteristic features of thoracic vertebrae. Large massive vertebral bodies are characteristic of the lower half of the vertebral column (i.e. lower thoracic and lumbar vertebrae).

You also suspect that the knife cut may have resulted in nerve damage. Flexion at the glenohumeral joint appears somewhat compromised, while abduction, adduction and extension are normal. To further test flexion, you ask the patient to abduct his left arm to 90° and ask him to move the arm forward while you try to prevent him from doing so (i.e., he's then flexing against resistance). With your other hand, you palpate immediately inferior to the clavicle and feel no contraction of muscle. You continue your exam by determining whether there are any other motor deficits and find that movements at the elbow and wrist joints are normal, as are movements of the fingers. Using an open safety pin, you also determine that cutaneous innervation of the upper limb is normal. From the diagram below, choose the most likely position for the nerve lesion.

Your examination reveals that the clavicular head of the pectoralis major is paralyzed. This indicates that the knife wound injured the lateral pectoral nerve, a branch of the lateral cord. Severing at site B (the lateral cord) or site C (the lateral pectoral nerve) could account for this loss of function (severing at sites A, D, E or F would not cause these symptoms). If the lateral cord were severed, the patient would have many additional muscular and cutaneous deficits (i.e. difficulty flexing at the elbow and wrist, numbness over the lateral arm and forearm). Since none of these deficits are present the knife must have severed at site C (the lateral pectoral nerve).

Flexion and extension of the thumb occur within _________ plane. A.the median sagittal (midsagittal) B.a coronal (frontal) C.a horizontal (transverse)

a coronal (frontal) Flexion and extension of the thumb occurs in the coronal plane (abduction and adduction occur in the sagittal plane). Remember that this is different from the fingers. Flexion and extension of the fingers occurs in the sagittal plane (abduction and adduction occur in the coronal plane).

Fractures of the scaphoid bone, usually from a fall on the outstretched hand, produce tenderness and swelling over the A.hypothenar eminence. B.dorsal (extensor) expansion of the index finger (2nd digit, 1st finger). C.common flexor sheath (ulnar bursa). D.anatomical "snuffbox."

anatomical "snuffbox." The scaphoid (and trapezium) lie in the floor of the anatomical snuffbox. Injury to the scaphoid results in localized tenderness in the anatomical snuffbox. The hypothenar eminence would not be affected as it is on the medial side of the palm, while the scaphoid bone is on the lateral side. The dorsal (extensor) expansion of the 2nd digit is an aponeurosis that runs from the proximal phalanx of the 2nd digit to the dorsal "hood" of the distal phalanx. This is too distal to be affected by the scaphoid fracture. The common flexor sheath contains the tendons of the flexor digitorum superficialis and profundus. It is too medial to be affected by the scaphoid fracture.

The lateral cord of the brachial plexus is located in the __________ and is formed by the union of the __________ divisions of the upper and middle trunks. A.axilla --- anterior B.axilla --- posterior C.posterior triangle of the neck --- anterior D.posterior triangle of the neck --- posterior

axilla --- anterior The cords of the brachial plexus are located in the axilla. The roots, trunks and divisions of the brachial plexus are found in the posterior triangle. The union of the anterior divisions of the upper and middle trunks forms the lateral cord. The posterior divisions of the upper and middle trunks contribute to the posterior cord along with the posterior division of the lower trunk.

A patient arrives in the emergency room after a car accident in which they severely damaged their elbow joint. You notice that at rest the patient holds their wrist slightly flexed and adducted. When you ask the patient to actively adduct OR flex at the wrist they always perform the two movements together and cannot separate them. When you ask the patient to extend at the wrist, they are unable to do so. This combination of deficits causes you to suspect that this person has sustained injury to the A.ulnar nerve alone. B.radial nerve alone. C.median nerve alone. D.both ulnar and median nerves. E.both radial and median nerves.

both radial and median nerves. In order to flex at the wrist without adducting or abducting, both the flexor carpi radialis (innervation = median n.) and flexor carpi ulnaris (innervation = ulnar n.) must be functioning. In order to adduct without flexing at the wrist, both the flexor carpi ulnaris (innervation = ulnar n.) and extensor carpi ulnaris (innervation = posterior interosseous/deep radial) must be functioning. Since this patient cannot separate flexion and adduction of the wrist, it indicates that the adductors at the wrist are unopposed and the abductors are compromised. The abductors at the wrist are the flexor carpi radialis (innervation = median n.) and extensor carpi radialis longus (innervation = radial n.) and brevis (innervation = posterior interosseous/deep radial n.). The inability to extend at the wrist also indicates paralysis of the extensor muscles of the forearm (innervation = radial n. and posterior interosseous/deep radial n.). Therefore, the ulnar nerve must be intact and the radial and median nerves must be injured.

The next three questions are linked. A patient arrives at the emergency room bleeding profusely and screaming that he has been stabbed. Pressure is applied to the wound and the bleeding is brought under control. Upon examination, you see that the patient has been stabbed in the region of the deltopectoral triangle (groove) on the left side. The bleeding was probably due to damage to both the __________ vein and branches of the __________ artery. A.basilic --- lateral thoracic B.basilic --- thoracoacromial C.cephalic --- lateral thoracic D.cephalic --- thoracoacromial

cephalic --- thoracoacromial The cephalic vein is located superficially in the deltopectoral triangle, where it pierces the clavipectoral fascia and joins the axillary vein. The basilic vein penetrates the deep fascia is located superficially on the medial side of the inferior arm and then joins with the brachial veins to form the axillary vein. The basilic vein does not pass through the deltpectoral triangle. Both the deltoid and acromial branches of the thoracoacromial artery are found in the deltopectoral triangle. The lateral thoracic artery descends along the axillary border of the pectoralis minor and follows it onto the thoracic wall. It is too inferior to be in the deltopectoral triangle.

A patient's subclavian artery is ligated just lateral to the anterior scalene muscle between the suprascapular artery and the thyrocervical trunk. In this patient, the dorsal scapular and transverse cervical arteries are branches of the thyrocervical trunk. The suprascapular artery is a direct branch of the subclavian. To fill the distal subclavian & axillary arteries, the flow of blood reverses direction in both the ________ arteries. A.transverse cervical and posterior intercostal B.dorsal scapular and circumflex scapular C.suprascapular and dorsal scapular D.circumflex scapular and suprascapular E.dorsal scapular and transverse cervical F.posterior intercostal and circumflex scapular

circumflex scapular and suprascapular Blood flow will reverse in arteries distal to the ligation, including the circumflex scapular and suprascapular arteries. Blood flow in arteries proximal to the ligation will not reverse direction (i.e. thyrocervical trunk, dorsal scapular, transverse cervical, posterior intercostals).

The tapering inferior part of the spinal cord is called the A.conus medullaris (medullary cone). B.lumbosacral enlargement. C.filum terminale. D.cauda equina. E.denticulate ligament.

conus medullaris (medullary cone) The tapering inferior part of the spinal cord is called the conus medullaris. The lumbosacral enlargement is superior to the conus medullaris and extends from the T11 to L1 segments of spinal cord. The filum terminale starts at the inferior end of the conus medullaris and descends with the spinal nerve roots in the cauda equina and attaches to the coccyx. The cauda equina is a bundle of spinal nerve ventral and dorsal roots caudal to the end of the spinal cord. Denticulate ligaments are lateral extensions of the pia mater that hold the spinal cord in position within the subarachnoid space.

Destruction of the ventral ramus of spinal nerve C8 would result in A.weakness of the deltoid muscle. B.a decrease in the number of axons in the ulnar nerve. C.a loss of cutaneous sensation in the lateral forearm. D.weakness in flexion at the shoulder joint.

decrease in the number of axons in the ulnar nerve. The axons in the ventral ramus of C8 get incorporated into the ulnar, median and radial nerves, and there would be a decrease in the number of axons in all of them (therefore B is correct). There would be no weakness in the deltoid since is innervated by the axillary nerve (C5, 6). The skin of the lateral forearm would not be affected because it is innervated by the lateral cutaneous nerve of the forearm (C5,6,[7]), which is the terminal part of musculocutaneous nerve. The flexors at the shoulder joint (clavicular head of the pectoralis major, deltoid, coracobrachialis) are innervated by the lateral pectoral nerve (C5, 6, 7), axillary nerve (C5, 6) and the musculocutaneous nerve (C5, 6, [7]) and would not be affected by damage to the ventral ramus of C8.

A physician places a card between a patient's 1st (index) and 2nd (middle) fingers. The patient is asked to hold the card tightly while the physician tries to pull the card away. The physician has tested the integrity of the ______ nerve. A.deep branch of the ulnar B.superficial branch of the ulnar C.median D.deep branch of the radial E.superficial branch of the radial

deep branch of the ulnar The dorsal and palmar interossei are innervated by the deep branch of the ulnar nerve. The superficial branch of the ulnar nerve supplies palmaris brevis and sensation to skin of the 4th (little) and medial part of the 3rd (ring) finger. The median nerve supplies the thenar muscles (except adductor pollicis and deep head of flexor pollicis brevis), the lumbricals of the 1st and 2nd fingers, and provides sensation to skin of the lateral 3 and one-half digits. The deep radial nerve innervates the posterior compartment of the forearm. The superficial branch of the radial nerve has an entirely cutaneous distribution.

An untreated pinprick in the index finger (1st finger, 2nd digit) may result in an infection that leads to pain, tenderness and inflammation in the ________________. If the synovial membrane of this structure were to rupture, the infection and accompanying symptoms would most likely spread to the _____________ space. A.common flexor sheath --- midpalmar B.common flexor sheath --- thenar C.digital synovial sheath of the index finger --- midpalmar D.digital synovial sheath of the index finger --- thenar

digital synovial sheath of the index finger --- thenar The digital synovial sheath surrounding the flexor digitorum superficialis and profundus in the index finger can be punctured by a deep pinprick. The common flexor sheath is the synovial sheath that encloses the flexor tendons in the carpal tunnel and typically communicates with the digital synovial sheath of the little (4th) finger, as well as the synovial sheath of the flexor pollicis longus. There are two fascial spaces deep to the palmar aponeurosis. The thenar space is the lateral space that contains the flexor pollicis longus tendon and the other flexor tendons of the index finger. The midpalmar space is the medial space that contains the flexor tendons of the medial three digits.

There are cell bodies of sensory general afferent (GA) neurons in A.paravertebral (sympathetic chain) ganglia. B.dorsal root (spinal) ganglia. C.the ventral horn of the spinal cord. D.the intermediolateral nucleus (horn) of the spinal cord.

dorsal root (spinal) ganglia Dorsal root ganglia contain the cell bodies of sensory general afferent (GA) neurons. Paravertebral ganglia contain the cell bodies of postsynaptic sympathetic general visceral efferent (GVE) neurons. The ventral horn of the spinal cord contains the cell bodies of general somatic efferent (GSE) neurons. The intermediolateral nucleus of the spinal cord contains cell bodies of presynaptic sympathetic general visceral efferent (GVE) neurons.

A patient has a fracture of the proximal end of the radius that completely severs the deep branch of the radial nerve close to its origin. On the affected side this patient would A.be completely unable to flex at the wrist joint. B.be completely unable to extend at the elbow joint. C.be unable to feel heat or cold on the dorsal surface of the forearm. D.exhibit a weakness in supination.

exhibit a weakness in supination The radial nerve divides in the cubital fossa into the deep and superficial radial nerves. The deep branch penetrates and supplies the supinator muscle to reach the posterior compartment of the forearm to supply the muscles in that compartment. Damage to the deep radial nerve results in an inability to extend at the wrist or the MP joints, and a weakness in supination (Answer D). This function will not be eliminated since the biceps brachii will be unaffected. The deep radial nerve does not have a cutaneous distribution, so there would be no sensory deficits. Flexion at the wrist (anterior compartment of the forearm) would not be compromised since the median and/or ulnar nerves are unaffected. Extension at the elbow joint would not be compromised because the triceps is innervated by the radial nerve in the upper arm.

This person's thumb is fully __________. This movement occurs in the __________ plane. (picture of thumbs up) A.abducted --- coronal B.abducted --- sagittal Correct C.extended --- coronal D.extended --- sagittal

extended --- coronal Flexion and extension of the thumb occurs in the coronal plane, while abduction and adduction occur in the sagittal plane. In the picture the thumb is fully extended. Remember to always refer to anatomical position, not the way it looks in the picture.

The __________ muscles cross the metacarpophalangeal (MP) joint of the thumb. A.abductor pollicis longus and opponens pollicis B.opponens pollicis and flexor pollicis brevis C.flexor pollicis brevis and extensor pollicis brevis D.extensor pollicis brevis and abductor pollicis longus

flexor pollicis brevis and extensor pollicis brevis The flexor pollicis brevis and the extensor pollicis brevis cross the MP joint of the thumb, as their distal attachment is on the base of the proximal phalanx of the thumb. The abductor pollicis longus and opponens pollicis do not cross the MP joint, as they attach to the first metacarpal.

The radial nerve lies on the posterior surface of the humerus between the humeral attachments of the __________ heads of the triceps and is accompanied by the ________. A.long & lateral --- deep artery of the arm (profunda brachii) B.long & lateral --- brachial artery C.long & medial --- deep artery of the arm (profunda brachii) D.long & medial --- brachial artery E.lateral & medial --- deep artery of the arm (profunda brachii) F.lateral & medial --- brachial artery

lateral & medial --- deep artery of the arm (profunda brachii) Only the lateral and medial heads of the triceps have proximal attachments to the humerus. The radial groove lies in between these attachments. The proximal attachment of the long head is to the infraglenoid tubercle of the scapula. The deep artery of the arm (profunda brachii) accompanies the radial nerve through the radial groove in the humerus. The brachial artery is in the anterior compartment.

The nerve that innervates all or most of the clavicular head of the pectoralis major is a branch of the ________ cord of the brachial plexus. It ________ have cutaneous branches that innervate the skin over the clavicle. A.lateral --- does B.lateral --- does not C.medial --- does D.medial --- does not

lateral --- does not The lateral pectoral nerve, a branch of the lateral cord, primarily innervates the clavicular head of the pectoralis major while the medial pectoral nerve, a branch of the medial cord, only innervates the sternocostal head of the pectoralis major. Neither the lateral nor medial pectoral nerves have a cutaneous component. The supraclavicular branches of the cervical plexus innervate the skin over the clavicle.

The __________ muscle is probably torn when a gymnast experiences sudden lumbar pain and muscle spasm while doing pulls-ups (chin-ups) on a high bar (extension against resistance). A.erector spinae B.deltoid C.latissimus dorsi D.trapezius E.serratus anterior

latissimus dorsi The latissimus dorsi is an extensor at the shoulder joint and an important climbing muscle. It functions whether the arm is moving and the trunk is stable, or vice versa. When performing chin-ups the arm is stable and the trunk is moving against gravity (extension against resistance. The erector spinae, deltoid, trapezius and serratus anterior do not cause extension at the shoulder joint.

The pectoralis minor is innervated by the ________ pectoral nerve and has an attachment to the _______. A.medial --- coracoid process B.medial --- bicipital groove of the humerus C.lateral --- coracoid process D.lateral --- bicipital groove of the humerus

medial --- coracoid process The medial pectoral nerve innervates the pectoralis minor and the sternocostal head of the pectoralis major. The lateral pectoral nerve innervates the clavicular head of pectoralis major. The pectoralis minor has an attachment to the coracoid process of the scapula. The pectoralis major has an attachment to the intertubercular (bicipital) groove of the humerus.

The presence of an anomalous, unilateral accessory rib articulating with vertebra C7 and attaching on rib 1 causes increasing pain, tingling and/or numbness along the medial side of the arm, forearm and hand of an elderly patient. There are no other cutaneous sensory deficits. Furthermore, examination revealed weakness in initiating pronation against resistance and weakness in flexion of the proximal (PIP) and distal (DIP) interphalangeal joints of the fingers and the interphalangeal joint of the thumb. There is no muscle weakness when extending the neck and upper part of the vertebral column. These neurological signs indicate that the rib may be stretching and exerting pressure on some axons of the __________. (All symptoms are from one injury site only) A.dorsal root of spinal nerve C7 B.dorsal ramus of spinal nerve C7 C.medial cord of the brachial plexus D.middle trunk of the brachial plexus E.dorsal root of spinal nerve C8 F.dorsal ramus of spinal nerve C8

medial cord of the brachial plexus Pain, tingling and/or numbness along the medial side of the arm, forearm and hand indicates involvement of spinal levels C8 (5th digit, medial side of hand, and forearm) and T1 (middle of forearm to axilla). Pronation is compromised indicating involvement of a branch of the median nerve that innervates the pronator teres (C6, C7) and/or the anterior interosseous nerve (C8, T1), a branch of the median nerve that innervates the pronator quadratus. Weakness in flexion of the PIP joints of the fingers indicates involvement of the flexor digitorum superficialis innervated by the median nerve (C7, C8, and T1), while compromised flexion at the DIP joints of the fingers indicates involvement of the flexor digitorum profundus and the ulnar (C8, T1) and median nerves (C8, T1). Flexion of the interphalangeal joint of the thumb is accomplished by the flexor pollicis longus innervated by the anterior interosseous nerve (C8, T1). Normal extension of the neck and upper vertebral column indicates the intrinsic muscles of the back and the dorsal rami of cervical spinal nerves are intact. Damage to a dorsal root or ramus, as well as the middle trunk, would account for some but not all of this patient's symptoms. All symptoms can be explained by damage to the medial cord proximal to the emergence of the medial cutaneous nerves of the arm and forearm.

Edema (swelling) in the carpal tunnel exerts pressure on the ___________ nerve and the ____________ tendons, resulting in severe pain and disability in the wrist and hand. A.median --- extensor digitorum B.median --- flexor digitorum profundus C.ulnar --- extensor digitorum D.ulnar --- flexor digitorum profundus

median --- flexor digitorum profundus The carpal tunnel is formed anteriorly by the flexor retinaculum and posteriorly by the carpal bones. It transmits the median nerve and the tendons of flexor pollicis longus, flexor digitorum profundus and flexor digitorum superficialis muscles. The ulnar nerve lies anterior to the flexor retinaculum and the extensor digitorum tendons lie posterior to the carpal bones; therefore neither is in the carpal tunnel.

Imagine a radiograph of a normal elbow in the AP projection. The __________ will have their shadows at least partially superimposed on this image. A.olecranon and trochlea B.head of the radius and the medial epicondyle of the humerus C.coronoid process of the ulna and capitulum D.lateral epicondyle of the humerus and the shaft of the radius

olecranon and trochlea Structures must be anterior and posterior to one another in the same transverse plane in order to be superimposed in an AP radiograph. This is true of the olecranon (on the posterior proximal ulna) and the trochlea (on the anterior distal humerus). The medial epicondyle of the humerus is supero-medial to the head of the radius. The coronoid process of the ulna is infero-medial to the capitulum of the humerus. The lateral epicondyle of the humerus is superior to the shaft of the radius.

A physician places a card between a patient's 1st (index) and 2nd (middle) fingers. The patient is asked to hold the card tightly while the physician tries to pull the card away. To hold the card tightly, the patient must contract the _________ interosseous muscle of the index finger and the _______ interosseous muscle of the middle finger. A.dorsal --- dorsal B.dorsal --- palmar C.palmar --- palmar D.palmar --- dorsal

palmar --- dorsal Abduction of the fingers involves moving away from the axial line that is through the 2nd (middle) finger. Adduction involves movement of the fingers towards the axial line. The dorsal interossei abduct and the palmar interossei adduct the fingers. Both interossei attached to the 2nd (middle) finger are considered dorsal interossei, since in both cases the finger is moving away from the axial line. In order to hold a card tightly between the 1st (index) and 2nd (middle) fingers, the index finger must adduct (palmar interosseous) and the middle finger must abduct (dorsal interosseous).

The __________ lies directly anterior to the axillary artery. A.anterior scalene B.posterior cord of the brachial plexus C.long thoracic nerve D.pectoralis minor muscle

pectoralis minor muscle The pectoralis minor lies directly anterior to the axillary artery. The anterior scalene lies directly anterior to the subclavian artery. The posterior cord lies posterior to the axillary artery. The long thoracic nerve bears no relationship to the axillary artery. It is initially posterior to the subclavian artery in the posterior triangle of the neck and is then found on the external surface of the serratus anterior.

The upper and lower subscapular nerves both arise from the ______________ cord of the brachial plexus. They can be differentially identified based on the innervation of the ________________ muscle. A.lateral --- subscapularis B.lateral --- teres major C.posterior --- subscapularis D.posterior --- teres major E.medial --- subscapularis F.medial --- teres major

posterior --- teres major The upper subscapular and lower subscapular nerves both arise from the posterior cord. While they both innervate the subscapularis, only the lower subscapular nerve innervates the teres major

The anterior boundary of the posterior triangle of the neck is formed by the A.medial one-third of the clavicle. B.anterior border of the trapezius muscle. C.posterior border of the sternocleidomastoid muscle. D.inferior belly of the omohyoid muscle.

posterior border of the sternocleidomastoid muscle. The anterior boundary of the posterior triangle is the posterior border of the sternocleidomastoid. The middle third of the clavicle between the trapezius and the sternocleidomastoid is the inferior boundary (base) of the posterior triangle. The anterior border of the trapezius is the posterior boundary of the posterior triangle. The inferior belly of the omohyoid is contained within the posterior triangle. It subdivides the posterior triangle into the occipital and omoclavicular (subclavian) triangles.

In this radiograph, region "A" is more __________ than region "B", because it is __________ than region "B." A.radiolucent --- thicker B.radiolucent --- denser C.radiopaque --- thicker D.radiopaque --- denser

radiopaque --- denser A tissue that absorbs a relatively large fraction of the x-ray beam passing through it is described as radiopaque (looks whiter/lighter in an x-ray), while a tissue that absorbs a relatively small fraction of the x-ray beam passing through it is described as radiolucent (looks blacker/darker in an x-ray). Absorption of x-rays by tissue is proportional to tissue density and thickness: the denser or thicker the tissue, the more x-rays it will absorb. The areas shown in A and B in this image are of similar thickness, therefore they differ in density. Bone is denser than soft tissue (i.e. muscle, blood).

Weeks after a nasty fall forward onto both hands, a patient arrives in the doctor's office complaining of clumsiness with the right thumb. The patient has no problem holding paper between any two fingers and has no difficulty in flexing the metacarpophalangeal (MP) joints and extending the interphalangeal (IP) joints of the fingers. Flexion and abduction of the thumb are weak and the thenar eminence is flat. However, sensation is normal over the thenar eminence, and extension and adduction of the thumb are normal. The nerve most likely affected is the A.recurrent branch of the median nerve. B.palmar cutaneous branch of the median nerve. C.median nerve in the cubital fossa. D.deep ulnar nerve E.deep radial (posterior interosseous) nerve.

recurrent branch of the median nerve. Flatness of the thenar eminence indicates that the thenar muscles have undergone atrophy. The abductor pollicis brevis, flexor pollicis brevis and opponens pollicis are innervated by the recurrent branch of the median nerve and they abduct and flex the thumb and medially rotate the 1st metacarpal during opposition. These muscles would be affected if the median nerve was damaged in the cubital fossa but the patient would then have problems flexing the metacarpophalangeal (MP) joints and would not be able to extend the interphalangeal (IP) joints of the index and middle fingers. In addition, there would be a sensory deficit on the palm of the hand. There are no sensory deficits so the palmar cutaneous branch of the median nerve is intact. If the deep ulnar nerve were affected the patient would not be able to flex the MP joints and extend the IP joints due to paralysis of the palmar and dorsal interossei muscles and the medial two lumbricals and the patient would not be able to hold the paper between their fingers. Injury of the deep radial nerve would result in difficulty extending the thumb (extensor pollicis brevis and longus). It would also compromise abduction of the thumb (abductor pollicis longus) that this patient exhibits, but there would be no effect extension and abduction of the thumb and could not completely explain the patient's symptoms.

The tissue normally supplied by the damaged artery does not become necrotic (death resulting from local deprivation of blood supply), because there are sufficient direct anastomoses between it and other arteries such as the __________ artery. A.superior (supreme) thoracic B.dorsal scapular C.thoracodorsal D.scapular circumflex

superior (supreme) thoracic In order for an artery to anastomose, it must supply an adjacent area (in this case, adjacent to the deltopectoral region). The superior thoracic artery branches from the axillary artery proximal to the thoracodorsal artery and supplies the first two intercostal spaces. It is supplying an area adjacent to that supplied by the pectoral branches of the thoracoacromial artery. The dorsal scapular artery runs deep to levator scapulae to reach the scapula and supply the rhomboids. It supplies the dorsal aspect of the scapula far from the deltopectoral triangle. The thoracodorsal artery supplies the latissimus dorsi muscle and the lateral thoracic wall. It is inferior to the deltopectoral triangle. The circumflex scapular artery curves around the axillary border of scapula to enter the infraspinous fossa. It anastomoses with arteries on the dorsal aspect of the scapula and is also far from the deltopectoral triangle.

The __________ nerves carry pain sensation from the glenohumeral joint. A.axillary and median B.median and ulnar C.ulnar and suprascapular D.suprascapular and axillary

suprascapular and axillary According to Hilton's Law, joints are innervated by articular branches of the nerves supplying the muscles that act on the joint and the skin over the joint. The axillary nerve innervates the teres minor and deltoid, both of which act at the glenohumeral joint. The suprascapular nerve innervates the supraspinatus and infraspinatus, both of which act at the glenohumeral joint. The median and ulnar nerves do not innervate any muscles that act at the glenohumeral joint.

The subacromial (subdeltoid) bursa lies immediately superior to the tendon of the __________ muscle. This bursa __________ communicate with the cavity of the glenohumeral joint. A.subscapularis --- does B.subscapularis --- does not C.supraspinatus --- does D.supraspinatus --- does not

supraspinatus --- does not The subacromial bursa is located between the acromion, coracoacromial ligament and deltoid superiorly and the supraspinatus tendon and glenohumeral joint capsule inferiorly. The subscapular bursa is located between the tendon of the subscapularis muscle and the neck of the scapula. The subacromial bursa does not communicate with the glenohumeral joint, while the subscapular bursa does communicate with the glenohumeral joint.

A sudden occlusion of the deep brachial (profunda brachii) artery at its origin would initially result in diminished blood flow A.to the lateral head of the triceps. B.to the short head of the biceps. C.into the deep palmar arch. D.into the common interosseous artery.

to the lateral head of the triceps The deep brachial (profunda brachii) artery branches off the brachial artery near its origin in the upper arm and accompanies the radial nerve along the radial groove in the humerus. The proximal attachment of the lateral head of the triceps is just superior to the radial groove, thus the initial portion of the profunda brachii would normally supply branches to this muscle. The deep brachial (profunda brachii) artery is in the posterior (extensor) compartment of the arm and not likely to supply the short head of the biceps that is in the anterior (flexor) compartment. The deep palmar arch and the common interosseous artery are branches of the radial and ulnar arteries, respectively. The radial and ulnar arteries are branches of the brachial artery and would not be affected by occlusion of the deep brachial (profunda brachii) artery

This is an image from an MRI exam of a normal wrist in the coronal plane. The first metacarpal is marked with an asterisk. The black dot is placed over the A.lunate. B.trapezoid. C.trapezium. D.capitate.

trapezium The carpal bone that articulates with the first metacarpal is the trapezium. The trapezoid and capitate articulate with the second and third metacarpals, respectively. The lunate is in the proximal row of carpal bones and does not articulate with a metacarpal.

Fractures of the olecranon are usually transverse. The proximal fragment is pulled superiorly by the _____________ muscle. A.biceps brachii B.triceps brachii C.supinator D.extensor carpi ulnaris

triceps brachii The muscle attached to the proximal portion of the olecranon is the triceps. The distal attachment of biceps brachii is the radial tuberosity and bicipital aponeurosis. Both the supinator and extensor carpi ulnaris attach to the ulna but inferiorly to the olecranon.

The lumbrical to the ring (3rd) finger is innervated by a branch of the ________ nerve that also innervates the part of the flexor digitorum ________ that has its distal attachment on the same finger. A.median --- superficialis B.median --- profundus C.ulnar --- superficialis D.ulnar --- profundus

ulnar --- profundus The lumbrical to the 3rd (ring) finger is innervated by the deep branch of the ulnar nerve. The ulnar nerve also innervates the medial part of the flexor digitorum profundus that has a distal attachment to finger 3. The median nerve innervates all of the flexor digitorum superficialis as well as the lateral part of the flexor digitorum profundus.

The flexor digiti superficialis and profundus form in the primitively __________ compartment of the limb bud and are innervated by nerves formed from ________ divisions of the brachial plexus. A.dorsal --- anterior B.dorsal ---- posterior C.ventral --- anterior D.ventral --- posterior

ventral --- anterior Muscles in the ventral compartments of the upper limb form within the ventral compartments of the limb bud. The ventral compartments are innervated by nerves formed from anterior divisions of the brachial plexus.

Postsynaptic (postganglionic) sympathetic axons are located in the __________ of spinal nerve C5. A.ventral and dorsal roots B.dorsal root and ventral ramus C.ventral and dorsal rami D.dorsal ramus and ventral roo

ventral and dorsal rami Both the ventral and dorsal rami of spinal nerve C5 contain postsynaptic sympathetic axons. Postsynaptic sympathetic axons are never found in the ventral or dorsal roots at any level of the spinal cord.

Postsynaptic (postganglionic) sympathetic axons are located in the __________ of spinal nerve C5. A.ventral and dorsal roots B.dorsal root and ventral ramus C.ventral and dorsal rami D.dorsal ramus and ventral root

ventral and dorsal rami Both the ventral and dorsal rami of spinal nerve C5 contain postsynaptic sympathetic axons. Postsynaptic sympathetic axons are never found in the ventral or dorsal roots at any level of the spinal cord.