Anatomy Exam 2 - Practice Questions

While playing basketball, a 23-year old male falls on his outstretched left hand with the palm down. Two days later he notes that his wrist is slightly swollen and tender but without deformity. His anatomical "snuff box" is tender to deep palpation, especially when the thumb is extended. What is the most likely diagnosis?

Wrist fracture

A 48-year old heavy smoker has a 1-week history of neck swelling, dyspnea, and the sensation of something pushing on his throat. Three weeks previously, de developed nasal stuffiness and voice hoarseness. He has a reddish-blue face, facial edema and jugular venous distention. Most likely cause:

bronchogenic lung cancer

Match the following nerve roots (A - F) to their locations on the body. A. C6 B. C7 C. T1 D. T4 E. T7 F. T10 1. Umbilicus 2. Nipple 3. xiphoid process 4. index finger

1. Umbilicus - T10 2. Nipple - T4 3. xiphoid process - T7 4. index finger - C6

1. A patient has been lying down in bed for 4 months. her normal, quiet expiration is achieved by contraction of which of the following structures? A. elastic tissue in the lungs and thoracic wall B. pectoralis minor muscles C. serratus anterior muscle D. anterior abdominal wall muscles E. external intercostal muscles

A

1. In an attempt to obtain a blood sample from a patient's median cubital vein, a nurse inadvertently procures arterial blood. The blood most likely comes from which of the following arteries? A. brachial B. radial C. ulnar D. common interosseous E. superior ulnar collateral

A

2. After initial examination, a patient is sent to radiology. Radiographs reveal that the portion of the scapula forming the tip or point of the shoulder has been fractured. This bone is the: A. acromion B. superior angle C. coracoid process D. glenoid fossa E. spine of scapula

A

4. A patient has a small tumor in the mediastinum which is confined at the level of the sternal angle. Which of the following structures would most likely be found at this level? A. bifurcation of the trachea B. beginning of the ascending aorta C. middle of the aortic arch D. articulation of the third rib with the sternum E. superior border of the superior mediastinum

A

5. Which of the following is most vulnerable during incision of the fibrous pericardium? A. Phrenic nerve B. Ligamentum arteriosum C. Inferior vena cava D. Vagus

A

6. A patient is found to have a melanoma (cancer arising in pigment cells) originating in the skin of the left forearm. After removal of the tumor from the forearm, all axillary lymph nodes lateral to the medial edge of the pectoralis minor muscle are removed. Which axillary lymph nodes would not be removed by this procedure? A. Apical B. Central C. Lateral D. Pectoral E. Subscapular

A

6. General sensation from the fibrous pericardium is supplied by which of the following? A. phrenic nerves B. intercostal nerves C. vagus nerve D. sympathetic nerves

A

7. In the axilla the pectoralis minor is a landmark, being closely related to all of the following structures except: A. cephalic vein B. cords of the brachial plexus C. lateral thoracic artery D. medial pectoral nerve E. second part of the axillary artery

A

8. A pulmonary embolism involves a blood clot that obstructs blood flow in which structure associated with the lung? A. pulmonary artery B. bronchial artery C. pulmonary vein D. bronchial artery

A

What is the most likely nerve injured?

A 17 year old football player was attempting to make a tackle with an outstretched left arm. The arm was hit with substantial force, and he now complains of severe shoulder pain and his left arm is hanging down with some external rotation. He does not move the limb due to the pain. An X-ray is negative for a fracture, but the head of the humerus is superimposed on the neck of the scapula. The shoulder is the most commonly dislocated large joint in the body, and the great majority is in an anterior direction (see figure). Typically, the dislocation is also inferior such that the humeral head is located inferior and lateral to the coracoid process. The humeral head will often have an infraglenoid and infraclavicular position. The typical mechanism is that of a violent force to the humerus that is abducted and externally rotated, resulting in extension of the joint; this action displaces the humeral head inferiorly, ths tearing the weak inferior portion of the shoulder joint capsule. This is facilitated by the fulcrum effect of the acromion. The strong flexor and adductor muscles pull the humeral head anteriorly and medially to the subcoracoid position. In general, the patient will not move the arm and will support the limb flexed at the elbow with the opposite hand. The arm will be slightly abducted and medially rotated. The usually rounded curve of the shoulder is lost, and there is a depression evident inferior to the acromion. The humeral head is palpable, if not visible, in the deltopectoral triangle. First priorities are assessment of the neural and vascular integrity of the upper limb by testing motor and sensory functions of the fingers and palpation of the radial pulse. Other injuries that may accompany a shoulder dislocation include strain on the tendons of the subscapularis and supraspinatus muscles, tears of the glenoid labrum, fracture of the greater tubercle of the humerus, trauma to the axillary nerve (as demonstrated by loss of sensation in the lateral part of the shoulder) and trauma to the axillary artery or its branches such as the posterior circumflex or subscapular arteries.

3. A 49 year old woman is diagnosed with having a large lump in the upper lateral quadrant of her right breast. Breast cancer from this region drains primarily first into which of the following nodes? A. apical nodes B. anterior (pectoral) nodes C. parasternal nodes D. supraclavicular nodes E. superficial inguinal nodes

A or somtimes B

A 65 year old man develops a myocardial infarction and is noted to have a heart rate of 40 beats per minute. The cardiologist diagnoses an occlusion of the right coronary artery. Which of the following is most likely affected? A. AV node B. BundleofHis C. Purkinjefibers D. Mitral valve

A. AV node

A 47 year old man is involved in a motor vehicle accident and receives a fatal tear at the junction of the SVC and the right atrium. This tear would likely damage the: A. SA node B. AVnode C. AVbundle D. Right bundle branch E. Left bundle branch

A. SA node

The artery which normally supplies blood to the AV node is the: A. right coronary B. rightmarginal C. posteriorinterventricular D. anterior interventricular E. circumflex artery

A. right coronary

Which artery most often supplies the SA node of the heart? A. right coronary B. rightmarginal C. posteriorinterventricular D. anterior interventricular E. circumflex artery

A. right coronary

A 23-year old woman falls onto her outstretched hand. You suspect a fracture of a carpal bone. Which of the following bones is most likely fractured? A. scaphoid B. lunate C. triquitrum D. pisiform E. capitate

A. scaphoid

A baseball player has shoulder discomfort and you suspect a rotator cuff tear. Which of the following tendons is most likely damaged? A. supraspinatus B. infraspinatus C. subscapularis D. teres major E. teres minor

A. supraspinatus

A 35 year old woman comes to your office tired and complaining of shortness of breath and fatigue. On examination, her heart rate is 120 beats/ min, and the rhythm has no discernible pattern. Auscultation of the heart indicates a systolic murmur. What is the most likely diagnosis?

Atrial fibrillation due to left atrial enlargement

1. A 45 year old woman presents with a tumor confined to the posterior mediastinum. This could result in compression of which of the following structures? A. trachea B. descending aorta C. arch of the aorta D. arch of the azygo vein E. phrenic nerve

B

2. After falling off his bike, a 10 year old boy has weakness in laterally rotating his arm. His X-ray reveals a fracture of the surgical neck of his humerus and bleeding from the point of fracture. Which of the following nerves are most likely injured as a result of this accident? A. musculcutaneous B. axillary C. radial D. median E. ulnar

B

2. During the procedure, the needle hits a nerve medial to the artery. Which of the following nerves is most likely damaged? A. radial B. median C. ulnar D. lateral antebrachial E. medial antebrachial

B

3. A 62 year old woman has an advanced lung cancer that spread into her second right intercostal space posterior to the midaxillary line. If cancer cells are carried in the venous drainage, they would first travel to which of the following veins? A. superior vena cava B. right superior intercostal vein C. right brachiocephalic vein D. azygous vein E. hemiazygous vein

B

4. A 17 year old boy is injured in an automobile accident. He has a fracture of the shaft of his humerus. Which of the following nerves is likely damaged? A. axillary B. radial C. musculcutaneous D. median E. ulnar

B

7. A 22-year-old male involved in an automobile accident presents with symptoms suggestive of myocardial contusion due to blunt trauma, specifically compression of the sternocostal surface of the heart by the sternum when his chest hit the steering wheel. Which heart chamber was most likely damaged? A. right atrium B. right ventricle C. left atrium D. left ventricle

B

7. Mitral valve stenosis (narrowing) might result in increased pressure and dilation of which blood vessel(s)? A. pulmonary arteries B. pulmonary veins C. SVC & IVC D. aorta E. coronary sinus

B

8. An autopsy of a person who suffered a heart attack due to diminished blood flow in the coronary arteries. This most likely resulted from embolization of an atherosclerotic plaque at the origin of which of the vascular structures? A. pulmonary trunk B. ascending aorta C. coronary sinus D. descending aorta E. aortic arch

B

8. If the thoracic duct is blocked or ruptured, lymphatic drainage fom which area remains normal? A. left thorax B. right thorax C. left abdomen D. right pelvis E. left lower limb

B

6. A man riding a motorcycle hit a wet spot in the road, lost control, and was thrown from his bike. He landed on the right side of his head and the tip of his shoulder, bending his head sharply to the left and stretching the right side of his neck. Subsequent neurological examination revealed that the roots of the 5th and 6th cervical nerves had been torn away from the spinal cord. Whichh of the following motions of the humerus at the shoulder would be most affected? A. adduction B.. abduction C. flexion D. extension E. medial rotation

B due to damage to the axillary and suprascapular nerves

A 65 year old woman underwent surgery to remove her uterus two days previously. She was doing well until today, when she developed shortness of breath, and she describes a sharp pain in the right side of her chest at inspiration. On physical examination, her respiratory rate is 28 breaths/min and a heart rate of 110 beats/min. What is the most likely diagnosis?

pulmonary embolism

1. A 12 year old boy is diagnosed with an upper brachial plexus injury after falling from a tree. He presents with his right upper arm at his side due to loss of abduction. The muscles primarily responsible for abduction of the arm at the shoulder are the: A. deltoid and biceps B. deltoid and supraspinatus C. deltoid and infraspinatus D. supraspinatus and infraspinatus E. corocobrachialis and supraspinatus

B. deltoid and supraspinatus

You are examining an axial cross section MRI scan of the wrist and have identified the carpal tunnel. The structure that forms the anterior wall of the tunnel is the: A. palmar aponeurosis B. flexorretinaculum C. extensorretinaculum D. deep fascia

B. flexorretinaculum

As the median nerve is about to pass through the carpal tunnel it is located: A. just lateral to the flexor carpi radialis tendon B. just medial to the flexor carpi radialis tendon C. just medial to the flexor Palmar is longus tendon D. just lateral to the flexor Palmaris longus tendon E. just medial to the flexor carpi ulnaris tendon

B. just medial to the flexor carpi radialis tendon

During a surgical procedure, a surgeon has reflected the fat pad containing the thymic remnants and notes a large venous structure crossing the midline from the left and apparently emptying into the SVC. This vessel is most likely the: A. right bracheocephalic vein B. leftbracheocephalicvein C. left internal jugular vein D. left subclavian vein E. azygous vein

B. left bracheocephalic vein

You are examining an X-ray of a patient's wrist and note dislocation of one of the carpal bones. The dislocated carpal bone is most likely the: A. scaphoid B. lunate C. triquitrum D. capitate E. hamate

B. lunate

A 44 -year old woman who has a DVT of the lower extremity suddenly gasps and collapses. She is found to be hypotensive. Resuscitative measures are attempted without success. Which of the following is the most likely diagnosis? A. myocardial infarction B. saddle embolus C. rightperipheralpulmonaryembolus D. embolic stroke

B. saddle embolus

While performing this procedure, the lower border of the lung will lie at the level of which rib in the mid-clavicular line? A. fifth B. sixth C. seventh D. eighth E. ninth

B. sixth

A 32-year old woman delivered a 10.5 lb baby vaginally after some difficulty with her labor. At delivery, the infant's head emerged but the shoulders were "stuck" behind the mother's symphysis pubis, requiring the obstetrician to apply some effort and maneuvers to free up the infant's shoulders and complete the delivery. The infant was noted to be healthy except he was not moving its right arm. What is the most likely diagnosis?

Brachial plexus injury, probably Erb's palsy

1. A 27 year old pianist with known carpal tunnel syndrome experiences difficulty in finger movements. Which of the following intrinsic muscles of her hand is affected? A. palmar interossei and adductor pollicis B. dorsal interossei and lateral two lumbricals C. lateral two lumbricals and opponens pollicis D. abductor pollicis brevis and palmar interossei E. medial two and lateral two lumbricals

C

1. A rock climber falls on his shoulder, resulting in a fracture of the lesser tubercle of the humerus. Which of the following structures would most likely have structural and functional damage? A. supraspinatus muscle B. infrapsinatus muscle C. subscapularis muscle D. teres minor muscle E. coracohumeral ligament

C

1. An elderly lady suffers a coronary occlusion and subsequently it is noted that there is a complete heart block (that is, the right and left bundles of the conduction system have been damaged). The artery most likely involved is the: A. left marginal B. left circumflex C. anterior interventricular D. posterior interventricular E. right

C

1. The first large artery that branches from the aorta is the A . left common carotid B . left subclavian C . brachiocephalic D . left internal thoracic E . first posterior intercostal

C

2. A man is unable to hold a pen between his index and middle fingers. WHich of the following nerves was likely injured? A. radial B. median C. ulnar D. musculcutaneous E. axillary

C

2. The sternal angle is located at about which vertebral level? A. T2/T3 B. T3/T4 C. T4/T5 D. T6 E. T9

C

3. A 22 year old dancer fell from the stage and complains of elbow pain and total inability to supinate her forearm. Which of the following nerves are most likely injured from this accident? A. median and ulnar B. axillary and radial C. radial and musculocutaneous D. ulnar and axillary E. musculcutaneous and median

C

3. This accident most likely leads to damage of which of the following arteries? A. axillary B. deep brachial C. posterior circumflex humeral D. thoracodorsal E. circumflex subscapular

C

3. Which of the following is found in the anterior mediastinum? A . trachea B . phrenic nerve C . thymus D . vagus E . pericardiophrenic artery

C

3. Which of the following is true about the right atrium? A. contains trabeculae carnae B. is associated with the apex of the heart C. contains the sonoatrial node D. receives the right pulmonary vein E. is hypertrophied by pulmonary stenosis

C

4. Which posterior mediastinal structure is most closely applied to the posterior surface of the pericardial sac? A. aorta B. azygous vein C. esophagus D. thoracic duct E. trachea

C

5. A 21 year old patient with a stab wound reveals laceration of the right vagus nerve proximal to the origin of the recurrent laryngeal nerve. Which of the following conditions would most likely result in this lesion? A. contraction of the bronchial muscle B. stimulation of bronchial gland secretion C. dilation of the bronchial lumen D. decrease in heart rate E. constriction of a coronary artery

C

5. A 57 year old patient has a heart murmor resulting from the inability to maintain constant tension on the cusps of the left atrioventrivicular valve. Which of the following structures is most likely damaged? A. crista terminalis B. moderator band C. chordae tendinae D. pectinate muscle E. opening for coronary sinus

C

7. The sternocostal surface of the heart is formed primarily by the anterior wall of which heart chamber? A. right atrium B. left atrium C. right ventricle D. left ventricle E. ascending aorta

C

A 45-year old woman requires an arterial blood gas specimen for management. If you are planning to draw the sample from the brachial artery, you should insert the needle: A. In the lateral aspect of the arm, between the biceps and triceps muscles B. Justlateraltothebicepstendoninthecubitalfossa C. Just medial to the biceps tendon in the cubital fossa D. Just medial to the tendon of the flexor carpi radialis muscle at the wrist E. Just medial to the tendon of the flexor carpi radialis muscle at the wrist

C. Just medial to the biceps tendon in the cubital fossa

A patient with a severe tear of the medial collateral ligament of the wrist would likely display which of the following increased wrist movements? A. flexion B. extension C. abduction D. adduction E. pronation

C. abduction

A 24-year old man is noted to have a midshaft humeral fracture after falling from a scaffold. Which of the following muscle tests would you perform to test the integrity of the radial nerve? A. flexion of the forearm at the elbow B. flexionofthehandatthewrist C. extension of the hand at the wrist D. abduction of the index, middle, ring and little fingers E. adduction of the index, middle, ring and little fingers

C. extension of the hand at the wrist

As a radiologist examining a contrast study of the pulmonary vessels, you will note how many pulmonary veins entering the left atrium? A. two B. three C. four D. five E. Six

C. four

You are explaining the anatomy of the shoulder to a young athlete who has sustained an injury to one of his shoulders. You tell him the chief stability to this joint is from the: A. glenohumeral ligaments B. acromioclavicularligament C. rotator cuff muscles D. corococlavicular ligaments E. coroacohumeral ligament

C. rotator cuff muscles

A pediatric heart surgeon has just divided the sternum in a child to repair a cardiac malformation. A lobulated gland-like structure is seen immediately obscuring the heart. This is most likely the: A. lung B. thyroid gland C. thymus D. lymph nodes E. liver

C. thymus

A 34-year old pregnant woman complains of tingling of her right index and middle fingers over 2 month's duration. She notes some weakness in her right hand and has begun to drop items such as her coffee cup. She has otherwise been healthy and denies any trauma or neck pain. What is the most likely diagnosis?

Carpal tunnel syndrome

A 34-year old pregnant woman complains of tingling of her right index and middle fingers over 2 month's duration. She notes some weakness in her right hand and has begun to drop items such as her coffee cup. She has otherwise been healthy and denies any trauma or neck pain. What is the anatomic mechanism for this condition?

Compression of the medial nerve as it passes through the carpal tunnel of the wrist. The most likely cause for this individual's symptoms is carpal tunnel syndrome. The carpal tunnel is a confined, rigid space at the wrist that contains nine tendons with their synovial sheaths and the median nerve (see figure). Any condition that further reduces the available space within the tunnel may compress the median nerve, producing numbness and pain in the areas of cutaneous distribution, muscle weakness (especially in the thumb), and muscle atrophy after long-term compression. The median nerve may be compressed in several sites along its length between the brachial plexus and the hand, but the carpal tunnel is the most common site. Carpal tunnel syndrome has been associated with endocrine conditions such as diabetes, hypothyroidism, hyperthyroidism, acromegaly, and pregnancy. Other causes include autoimmune disease, lipomas within the canal, hematomas, and carpal bone anomalies. Females are more commonly affected than males in a ratio of 3;1. initial treatment is a nighttime splint of the wrist and avoidance of excessive activity within the hand. If these symptoms do not decrease, division of the floor of the flexor retinaculum (carpal tunnel release) may be necessary.

A 32-year old man is involved in a motor vehicle accident. He has multiple injuries including a displaced fracture of the left humerus. He complains of an inability to open his left hand and loss of sensation to a portion of his left hand. What is the likely mechanism of the injury?

Crush injury of the radial nerve as it spirals around the midshaft of the humerus

1. A 29 year old man comes to the ER with a stab wound and cannot raise his arm above horizontal and exhibits a condition known as "winged scapula". Which of the following structures would most likely be damaged? A. medial cord of brachial plexus B. posterior cord of brachial plexus C. lower trunk of brachial plexus D. roots of brachial plexus E. upper trunk of brachial plexus

D

2. A 27 year old patient has an aneurysm of the aortic arch. This may compress which of the following structures? A. right vagus nerve B. left phrenic nerve C. right sympathetic trunk D. left recurrent laryngeal nerve E. left greater splanchnic nerve

D

2. During the cardiac cycle, which of the following events occurs? A. atrioventricular valves close during diastole B. aortic vlave closes during systole C. pulmonary valve opens during diastole D. blood flow in coronary arteries is maximal during diastole E. aortic valve closes at the same time as teh AV valves

D

2. The fossa ovalis (a remnant of the oval foramen and its valve) is an internal feature of the A . left atrium B . left ventricle C . conus arteriosus D . right atrium E . right ventricle

D

3. A thoracentesis is performed to aspirate and abnormal acululation of fluid in a patient with a pleural effusion. A needle should be inserted in the midaxillary line between which of the following two ribs so as to avoid puncturing the lung? A. ribs 1 and 3 B. ribs 3 and 5 C. ribs 5 and 7 D. ribs 9 and 10 E. ribs 10 and 11

D

3. Damage to the median nerve in the hand is likely to produce which of the following conditions? A. waiter's tip upper limb B. claw hand C. wrist drop D. Ape hand E. flattening of the hypothenar eminence

D

4. The projection of the heart on the anterior chest wall is such that the sternocostal or anterior surface of the heart is formed primarily by the: A . right atrium B . left atrium C . left ventricle D . right ventricle E . roots of the great vessels

D

4. Where should a stethescope be placed to best hear sounds from the mitral valve? A. over the medial end of the second left intercostal space B. over the medial end of the second right intercostal space C. in the left fourth intercostal space at the midclavicular line D. in the left fifth intercostal space at the midclavicular line E. over the right half of the lower end of the body of the sternum

D

4. Which of the following is not a direct branch of the axillary artery? A. anterior circumflex humeral B. posterior circumflex humeral C. thoracoacromial D. thoracodorsal E. subscapular

D

5. Following this accident, the patient would have no cutaneous sensation in which of the following areas? A. medial aspect of arm B. lateral aspect of arm C. palmar aspect of second and third digits D. area of anatomical snuffbox E. medial one and one-half fingers

D

5. Shoulder separations involve tearing of which of the following ligaments? A. glenohumeral B. corocoacromial C. tendon of long head of biceps D. acromioclavicular E. transverse scapular

D

6. Which of the following is true of the left main stem bronchus? A. has a larger diameter than the right main stem bronchus B. often receives more foreign bodies that the right main stem bronchus C. gives rise to the eparterial bronchus D. is longer than the right primary bronchus E. runs under the arch of the azygos vein

D

6. a 14 year old boy falls on his outstretched hand and has a fracture of the scaphoid bone. The fracture is most likely accompanied by a rupture of which of the following arteries? A. brachial B. ulnar C. deep palmar arterial arch D. radial artery E. anterior interosseous artery

D

9. The right bronchus is __________ than the left bronchus. A.straighter B. wider C. more likely to receive aspirated objects D. all of above

D

The blood supply to the majority of the interventricular septum is supplied by which coronary artery? A. right coronary B. rightmarginal C. posteriorinterventricular D. anterior interventricular E. circumflex artery

D. anterior interventricular

In which of the following structure is the AV bundle found? A. right atrium B. leftatrium C. interatrialseptum D. membranous interventricular septum E. muscular interventricular septum

D. membranous interventricular septum

As a surgeon exploring the thorax, you will be able to identify the right pulmonary artery by its position: A. anterior to the ascending aorta and the SVC B. anteriortotheascendingaortaandposteriortotheSVC C. posteriortothedescendingaortaandtheSVC D. posterior to the ascending aorta and the SVC E. posterior to the ascending aorta and anterior to the SVC

D. posterior to the ascending aorta and the SVC

An 18-year old patient has been improperly fitted with axillary-type crutches, which have put pressure on the posterior cord of the brachial plexus. Which of the following terminal nerves would most likely be affected? A. axillary nerve B. musculocutaneousnerve C. mediannerve D. radial nerve E. ulnar nerve

D. radial nerve

While performing this thoracentesis procedure, the lowest level of the pleural cavity will lie at the level of which rib at the end of expiration? A. seventh B. eighth C. ninth D. tenth E. eleventh

D. tenth

2. Injury to the lateral cord of the brachial plexus will also injure one of its branches, the musculocutaneous nerve. Which of the following findings would you observe in a patient with this injury? A. weakness of abduction of the arm at the shoulder B. weaknessofadductionofthearmattheshoulder C. weaknessofextensionoftheforearmattheelbow D. weakness of flexion of the forearm at the elbow E. weakness of supination of the forearm and hand

D. weakness of flexion of the forearm at the elbow

A 65 year old woman underwent surgery to remove her uterus two days previously. She was doing well until today, when she developed shortness of breath, and she describes a sharp pain in the right side of her chest at inspiration. On physical examination, her respiratory rate is 28 breaths/min and a heart rate of 110 beats/min. What is the most likely location of the primary disease?

Deep vein thrombosis of the pelvis or lower limb This woman has multiple risks for DVT or blood clot formation within the large veins. These factors include the patient's age, likely minimal physical exercise, and bedrest after a major operation. Deep vein thrombi are typically asymptomatic but may cause lower limb swelling and pain. When pelvic or lower limb veins are involved, clot material can embolize and travel through the IVC and through the right side of the heart, whence they are pumped to the lungs, and where they will lodge in branches of the pulmonary arteries. These emboli effectively block blood flow beyond this point and prevent is unoxygenated blood from reaching the alveoli. The size and number of emboli produced will determine the amount of lung tissue that will be infracted due to lack of oxygen. The most common symptom of pulmonary embolism is dyspnea, and patients are often anxious, with tachycardia and pleuritic chest pain at inspiration. The next step would be an arterial blood gas study to assess oxygen status. A chest radiograph and ventilation- perfusion scan are performed to directly determine whether an embolus is present. If present, intravenous anti-coagulants such as heparin are beneficial. Large or untreated emboli can cause death. One particularly devastating type is called saddle embolus (see figure below). This type lodges in the pulmonary trunk at the bifurcation of the right and left pulmonary arteries, thus blocking blood flow to both lungs, leading to cardiovascular collapse and death.

A 32-year old man is involved in a motor vehicle accident. He has multiple injuries including a displaced fracture of the left humerus. He complains of an inability to open his left hand and loss of sensation to a portion of his left hand. What portion of the left hand is likely to have a loss of sensation?

Dorso-lateral side of the hand and dorsum of the thumb and index and middle digits. The radial nerve is at particular risk of injury in the radial groove as it spirals around the midshaft of the humerus. Humeral fractures (see figure) involving the midshaft region are of particular concern. There is a loss of innervation of the posterior extensor muscles in the forearm, resulting in wrist drop and an inability to extend the digits at the metacarpophalangeal (MP) joints. The sensory loss on the dorsum of the hand and digits reflects the distal cutaneous distribution of the radial nerve. The triceps muscle (extensor of the elbow) is typically spared; however the patient usually will not attempt to move the limb due to pain from the fracture. The deep brachial artery has the same path as the radial nerve in the radial groove and has a similar risk for injury.

4. A 21 year old man involved in an automobile accident is brought in to the ER with a fracture of the medial epicondyle of the humerus. Which of the following nerves is most likely injured as a result of this accident? A. axillary B. musculcutaneous C. radial D. median E. ulnar

E

4. Following the accident the boy has weakness in rotating his arm laterally. Which of the following muscles are paralyzed? A. teres major and teres minor B. teres minor and deltoid C. infraspinatus and deltoid D. supraspinatus and subscapularius E. teres minor and infraspinatus

E

5. After this injury, the patient is unable to do which of the following? A. flex the proximal interphalangeal joint of his ring finger B. flex the distal interphalangeal joint of his index finger C. feel sensation on his middle finger D. abduct his thumb E. adduct his index finger

E

5. Cell bodies of the injured nerve involved in movement of the boy's arm are located in which of the following structures? A. dorsal root ganglion B. sympathetic chain ganglion C.dorsal horn of the spinal cord D. lateral horm of the spinal cord E. ventral horn of the spinal cord

E

5. Since the puncture in the previous question was through the posterior wall of the esophagus, the doctors were also very concerned about possible damage to a thin-walled vessel just behind the esophagus and between the azygos vein and aorta, i.e., the: A. hemiazygous vein B. left bronchial vein C. left pulmonary vein D. superior vena cava E. thoracic duct

E

6. You are caring for a 68-year-old male who has copious amounts of fluid in the left pleural cavity due to acute pleurisy. When you examine him as he sits up in bed (trunk upright), where would the fluid tend to accumulate? A. middle mediastinum B. hilum C. cupola D. costomediastinal recess E. costodiaphragmatic recess

E

8. After falling from a ladder, a neurologic examination of 20 year old man reveals he has a lesion of the lateral cord of the brachial plexus. Which of the following muscles is most likely weakened by this injury? A. subscapularis B. teres major C. latissimus dorsi D. teres minor E. pectoralis major

E

A thoracic surgeon has entered the right pleural cavity and excised two suspicious lymph nodes at the hilum of the right lung for frozen section pathological study. These nodes belong to which of the following lymph node groups? A. parasternal B. paratracheal C. superior tracheobronchial D. inferior tracheobronchial E. bronchopulmonary

E. bronchopulmonary

You must remove fluid from the pleural cavity of your patient. You decide to insert the aspiration needle over the top of a rib into an intercostal space inferior to the lower border of the lung in the mid axillary line at the end of normal expiration. The highest level at which this procedure might safely be done without injuring the lung is the A. fourth intercostal space B. fifthintercostalspace C. sixthintercostalspace D. seventh intercostal space E. eighthintercostalspace

E. eighth intercostalspace

If the median nerve is severed at the wrist, which of the following would still retain their function? A. flexor pollicis brevis B. abductorpollicisbrevis C. opponenspollicis D. lumbricals of the index and middle fingers E. lumbricals of the ring and little fingers

E. lumbricals of the ring and little fingers

You are evaluating an X-ray of the only bony articulation between the upper limb and the trunk. Which of the following joints are you evaluating? A. glenohumeral B. acromioclavicular C. humeroclavicular D. coracoclavicular E. sternoclavicular

E. sternoclavicular

3. A 22 year old man is stabbed in the axilla with a knife. The physician suspects injury to the lower brachial plexus. Which of the following nerves is most likely affected? A. axillary B. musculocutaneous C. vagus D. radial E. ulnar

E. ulnar

A 54 year old smoker complains of acute onset of shortness of breath and severe pain with breathing. He has physical findings for chronic obstructive pulmonary disease with a barrel chest. There are decreased breath sounds and hyperresonance to percussion on the right side. What is the anatomical disorder?

Entry of air into the pleural space, resulting in lung collapse. If air enters the pleural space through the thoracic wall or the surface of the lung itself, the negative pressure of the pleural space equilibrates with atmospheric pressure, and air movement ceases. The defect that allowed air to enter the pleural space acts like a valve by preventing air from exiting the space. Pressure increases above that of atmospheric pressure, and a tension pneumothorax (see figure) results, which is characterized by lung collapse, with displacement toward the mediastinum. If severe enough, the mediastinum and its contents may be displaced toward the intact lung and produce partial compression of this lung. The most serious consequence of these anatomical shifts is decreased venous return to the heart. This patient who has chronic obstructive pulmonary disease is at risk for spontaneous pneumothorax by the rupture of an emphysematous bleb on the surface of the lung. Spontaneous pneumothorax may also occur from lung surface blebs in some people. The typical presentation of pneumothorax is chest pain with dyspnea, decreased breath sounds, and hyperresonance on the affected side. The diagnosis is confirmed by chest radiograph. Treatment is directed toward removal of air from the pleural space with a needle or by chest tube placed in the pleural space and directed to an underwater seal.

While playing basketball, a 23-year old male falls on his outstretched left hand with the palm down. Two days later he notes that his wrist is slightly swollen and tender but without deformity. His anatomical "snuff box" is tender to deep palpation, especially when the thumb is extended. What is the most likely anatomical defect?

Fracture of the narrow middle of the scaphoid carpal bone. This young man tripped while playing basketball and stretched out his right hand to protect himself. His hand, with the palm down and probably deviated to the side of the radius, took the brunt of the fall, resulting in significant impact force to the wrist. This results in pain and swelling of the wrist, especially on the radial side, with point tenderness deep in the anatomical snuffbox. This is the common mechanism for a fracture of the scaphoid carpal bone (see figure). Radiologic confirmation of the fracture is important (see figure). The scaphoid bone has a unique blood supply, and proper reduction and alignment of the segments is necessary to decrease the risk of avascular necrosis. A fall on an outstretched hand in a way that produces hyperextension of the wrist may result in dislocation of the lunate bone. The lunate is usually displaced anteriorly into the carpal tunnel and may impinge on the median nerve. The lunate is the most commonly displaced carpal bone. A fall on an outstretched palm may also result in a transverse fracture of the distal radius or a Colle's fracture. A Colle's fracture produces a dorsal displacement of the distal segment, resulting in a "dinner fork" deformity. In a Smith's fracture, there is trauma to the dorsal aspect of the flexed wrist, and the wrist is deformed with the distal radial fragment displaced ventrally in a "spade" deformity.

A 17 year old football player was attempting to make a tackle with an outstretched left arm. The arm was hit with substantial force, and he now complains of severe shoulder pain and his left arm is hanging down with some external rotation. He does not move the limb due to the pain. An X-ray is negative for a fracture, but the head of the humerus is superimposed on the neck of the scapula. What is the most likely diagnosis?

Glenohumeral joint dislocation.

A 68-year-old man complains of severe burning and stinging pain across the right side of his waist over a period of 2 days. Today, he noted a rash breaking out in the same area. On examination, there is a red rash with blisters staring on his back and curving down and across his waist region. What is the most likely diagnosis?

Herpes Zoster infection

A 32-year old man is involved in a motor vehicle accident. He has multiple injuries including a displaced fracture of the left humerus. He complains of an inability to open his left hand and loss of sensation to a portion of his left hand. What is the most likely diagnosis?

Injury to the radial nerve as it spirals around the humerus, resulting in an inability to extend the wrist or fingers and loss of sensation of the hand.

A 35 year old woman comes to your office tired and complaining of shortness of breath and fatigue. On examination, her heart rate is 120 beats/ min, and the rhythm has no discernible pattern. Auscultation of the heart indicates a systolic murmur What is the underlying etiology?

Mitral stenosis due to rheumatic heart disease. This 35-year old woman most likely has atrial fibrillation with tachydcardia that is irregularly irregular. Instead of the electrical impulse originating from the sinoatrial (SA) node of the right atrium and depolarizing both atria in a regular, orderly manner, this patient's atria have constant stimulation, leading to almost continual atrial contraction that visually resembles a "bag f worms". The irregular character of the pulse is the result of inconsistent transmission of the electrical impulse to and through the atrioventricular (AV) node and then onto the two ventricles. One common cause of atrial fibrillation is left atrial enlargement. In this patient, the history of childhood fever and joint pain is the result of streptococcally caused rheumatic fever. If untreated, the microorganism can cause inflammation of the mitral valve, leading to mitral stenosis. Over the course of years, the mitral stenosis is likely to worsen, leading to atrial enlargement, fibrillation and pulmonary edema with intolerance to physical exertion. Treatment in this patient would focus on decreasing her heart rate with an agent that acts on the AV node such as digoxin. Oxygen and diuretics would relieve her pulmonary symptoms. An ultimate goal will be the conversion of her cardiac contractions to a normal sinus rhythm. Anticoagulation is often warranted in the face of long-term atrial fibrillation because of the likelihood of intracardiac thrombus and the possibility of emboli after conversion to sinus rhythm, called the "atrial stunning" effect. Surgical correction of the mitral stenosis is also important.

A 59-year old hypertensive male smoker comes to the ER with tight chest pressure, shortness of breath and palpitations after exertion. His heart rate is 55 beats/min and regular. The electrocardiogram shows bradycardia, first degree heart block, and ST- segment elevation . What is the most likely diagnosis?

Myocardial infarction

A 54 year old smoker complains of acute onset of shortness of breath and severe pain with breathing. He has physical findings for chronic obstructive pulmonary disease with a barrel chest. There are decreased breath sounds and hyperresonance to percussion on the right side. What is the most likely diagnosis?

Pneumothorax

A 68-year-old man complains of severe burning and stinging pain across the right side of his waist over a period of 2 days. Today, he noted a rash breaking out in the same area. On examination, there is a red rash with blisters staring on his back and curving down and across his waist region. What is the anatomical explanation?

Reaction of the varicella virus and infection of the skin following the dermatomal distribution, in this case T11 or T12. This 68 year old man has clinical symptoms consistent with herpes zoster, aso known as shingles. The chicken pox virus remains latent and may become reactivated years later due to illness, stress or age. The varicella virus is reactivated from the dorsal root ganglia and initially causes a burning pain that follows the distribution of a dermatome, most commonly T3 through L3. Usually 2 to 3 days after the pain, a rash erupts that is erathematous and vesicular, and has a reddish blister-like appearance (see figure). Treatment of this condition may include corticosteroid therapy, which can help to decrease the inflammation and pain. Even after the skin lesions have healed, the patient can have significant pain called postherpetic neuralgia. The pain can persist for months or even years. Treatment of postherpetic neuralgia is difficult, and therapies include topical lidocaine gel, capsaicin cream, antoconvulsant agents, or even nerve blocks

A 59-year old hypertensive male smoker comes to the ER with tight chest pressure, shortness of breath and palpitations after exertion. His heart rate is 55 beats/min and regular. The electrocardiogram shows bradycardia, first degree heart block, and ST- segment elevation . What anatomical structures are most likely affected?

Right coronary artery and left anterior descending artery. This patient's 2-hour history of worsening chest pain, dyspnea, and palpitations after physical exertion is classic for a myocardial infarction. The pain of angina due to myocardial ischemia is typically deep, visceral, and squeezing in nature. It frequently radiates to the neck or left arm. The electrocardiogram (ST-segment elevation - see figure) is highly suspicious for myocardial infarction.Leads V1 and V2 are used to evaluate the anterior portion of the heart, which is supplied by the left anterior descending artery. Bradycardia and first degree heart block (increased PR interval) indicate right coronary artery disease.

A 48-year old heavy smoker has a 1-week history of neck swelling, dyspnea, and the sensation of something pushing on his throat. Three weeks previously, de developed nasal stuffiness and voice hoarseness. He has a reddish-blue face, facial edema and jugular venous distention. Anatomical structures likely involved:

SVC, trachea, and right mainstem bronchus The SVC receives venous drainage from the head, neck, upper limb and thorax. Located in the upper mediastinum, this thin-walled vessel is susceptible to pressure from external sources. The most common cause of such external compression is malignancy, usually from a right-sided lung tumor (see figure). Such tumors can also compress the trachea, producing dyspnea, and may involve the recurrent laryngeal nerve, producing hoarsness, as in this patient. The stellate sympathetic ganglion may be compressed, leading to Horner's syndrome, the clinical quartet of unilateral meiosis (constricted pupil), facial anhydrosis (dryness), and ptosis (drooping eyelid), and facial redness. The development of SVC syndrome is often an emergency because the trachea may be obstructed, leading to respiratory compromise. The priority in treatment is directed toward the airway, with oxygen and possibly diuretic agents, and corticosteroid agents to relieve the edema. A chest radiograph, CT scan (see figure), and a tissue biopsy, in that order, would be the next diagnostic steps. Most patients who have lung cancer are treated with radiotherapy. Although patients who have SVC syndrome often respond well to radiation treatment, the overall prognosis is nearly always poor due to the advanced extent of the cancer. Superior vena cava syndrome The patient was a 35-year-old man with a 3-year history of progressive upper-extremity and fascial swelling. The patient had undergone treatment for histoplasmosis in the past. CT scan shows a narrowed superior vena cava with adjacent calcified lymph nodes and posterior soft tissue thickening.

A 32-year old woman delivered a 10.5 lb baby vaginally after some difficulty with her labor. At delivery, the infant's head emerged but the shoulders were "stuck" behind the mother's symphysis pubis, requiring the obstetrician to apply some effort and maneuvers to free up the infant's shoulders and complete the delivery. The infant was noted to be healthy except he was not moving its right arm. What is the likely anatomical mechanism for this disorder?

Stretching of nerve roots C5 and C6 by an abnormal increase in the angle between the neck and the shoulder During delivery, particularly a large infant, shoulder dystocia (see figure- left) may occur. In this situation, the fetal head emerges, but the shoulder becomes wedged behind the maternal symphysis pubis. An obstetrician will use maneuvers such as flexing of the maternal hips against the maternal abdomen or fetal maneuvers such as pushing the fetal shoulders into an oblique position. These actions are designed to allow delivery of the fetal shoulders without excessive traction on the fetal neck. Despite such carefully executed maneuvers, infants may be born with stretch injuries to the brachial plexus, resulting in nerve palsies. The most common of these is an upper brachial plexus stretch injury in which the nerve roots C5 and C6, as well as the axillary and musculocutaneous nerves derived from them, are affected (see figure - right), resulting in the infant's arm being limp and to its side (waiter's tip position). Most such injuries resolve spontaneously.

A 32-year old woman delivered a 10.5 lb baby vaginally after some difficulty with her labor. At delivery, the infant's head emerged but the shoulders were "stuck" behind the mother's symphysis pubis, requiring the obstetrician to apply some effort and maneuvers to free up the infant's shoulders and complete the delivery. The infant was noted to be healthy except he was not moving its right arm. What is the most likely etiology for this condition?

Stretching of the upper brachial plexus during delivery

A 48-year old heavy smoker has a 1-week history of neck swelling, dyspnea, and the sensation of something pushing on his throat. Three weeks previously, de developed nasal stuffiness and voice hoarseness. He has a reddish-blue face, facial edema and jugular venous distention. Most Likely diagnosis:

Superior vena cava syndrome