I.      Buzzer Quiz

1.       A patient with lung cancer has been complaining of hoarseness. What is the name of the nerve which might be compressed by the tumor?

n  Answer：Recurrent laryngeal nerve

n  Comment：Majority of recurrent laryngeal nerve palsy in lung cancer patients is caused by either Pancoast tumor or aortic lymph invasion of the left lung. The latter is more common.

 

2.       Ca2+ATPase(SERCA) in the sarcoplasmic reticulum is activated by the stimulation of β₁adrenergic　receptor. In this activation pathway, what is the name of the substance phosphorylated by PKA?

n  Answer：Phospholamban

 

3.       Motor neurons receive an inhibitory input from their own collateral and prevent becoming hyperactive. What is the neurotransmitter that functions in the inhibitory neuron?

n  Answer：Glycine

 

4.       Basal metabolic rate can be estimated by using oxygen consumption and carbon dioxide production. What is the dimensionless number calculated from those two factors?

n  Answer：Respiratory quotient

 

5.       In patients with anti-phospholipid antibody syndrome(APS), autoantibody to the phospholipid of mitochondrial membrane appears in the serum. The phospholipid is composed of two molecules of Phosphatidylglycerols. The appearance of the antigen may cause a false positive result in what infectious disease?

n  Answer：Syphilis

n  Comment：Anticardiolipin antibodies are produced both in patients with the antiphospholipid syndrome (APS) and in patients with syphilis. Cardiolipin is a component of the inner mitochondrial membrane, composed of two molecules of phosphatidylglycerols binding to CoQ.

 

6.       Innate immune system shows nonspecific response. However, it has a system which recognizes specific molecular patterns of pathogens. What is the name of the group of these receptors?

n  Answer：pattern-recognition receptor

 

7.       A 30-year-old woman with amenorrhea was admitted to the hospital. On MRI, pituitary adenoma was found. In this woman, what hormone is over produced?

n  Answer：Prolactin

 

8.       What is the substance which reduces energy production through glycolytic pathway in skeletal muscle during exercise?

n  Answer：Mannose-6-phosphate

n  Comment：Lysosome has mannose-6-phosphate receptor. Mannose-6-phosphate in enzyme is combined to this receptor and incorporated into Lysosome.

 

9.       Histone is a positive charge protein because it contains a lot of basic amino acids, which enables to keep stable binding to negative charge DNA. What modification weakens this electrical interaction?

n  Answer：Acetylation

n  Comment：Acetylation neutralizes positive charge of histone by converting amino group of lysin into amide, which weakens electrical interaction between histone and DNA. This enables transcription factor and RNA polymerase to bind easily to DNA.

 

10.    What is the symptom called when attenuation of spontaneous breathing and disturbance of consciousness are induced by inhalation of high concentration of O₂ in a patient with type 2 chronic respiratory failure?

n  Answer: CO₂ narcosis

 

11.    When heat production increases, blood flow to the dermis also increases, which, in turn, increases the heat loss from the skin. What is the name of the structure that opens when this phenomenon occurs?

n  Answer：arterio-venous anastomoses

n  Comment：When the heat production decreases, the stimulation of sympathetic neurons cause the arteriovenous anastomoses to constrict, which, in turn, reduces the dermal blood flow and the heat is conserved. In this way the body temperature is regulated.

 

12.    AngiotensinⅠ is mainly converted into AngiotensinⅡ by ACE mainly. However, there is another enzyme in the mast cell which has the same function. What is the name of this enzyme?

n  Answer：Chymase

 

13.    During tracheal intubation, you should push a certain structure backward against the spine to prevent esophageal intubation. What is the structure that should be compressed?

n  Answer：Cricoid cartilage

n  Comment：The pressure to the cricoid cartilage, whose posterior surface is large can collapse the esophagus between the cricoid cartilage and the spine, thereby preventing the esophageal intubation.

 

14.    Rapid correction of metabolic acidosis is not recommended in patients with hypoxia caused by carbon monoxide poisoning. What is the name of the physiological phenomenon responsible for this concept of treatment?

n  Answer：Bohr effect

 

 

15.    Vitamin K carboxylates glutamate residue of the coagulation factor Ⅱ・Ⅶ・Ⅸ・Ⅹ. What ion attaches to the carboxyglutamate residue?

n  Answer：Calcium

n  Comment：Calcium is a divalent cation. It requires double glutamate residues.

 

16.    There is characteristic gene translocation in patients with chronic myelocytic leukemia. What method is used to detect genetic anomaly in which labeled oligonucleotide probe is used?

n  Answer：FISH (Fluorescence in situ hybridization)

 

17.    Gallstone has high impedance that a characteristic artifact is seen in ultrasonography. What is the name of this artifact?

n  Answer：Acoustic shadow

 

18.    Drug eluting stent is one of the most common stents used in endovascular treatment for myocardial infarction. A patient underwent the treatment using this stent needs to receive antiplatelet treatment, because the drug eluting from the stent has inhibitory effect on a specific cell. What cell is inhibited by the drug?

n  Answer：(Vascular) endothelium

n  Comment：Vascular endothelial cell has antiplatelet function. Endothelial injury, also known as one of the Virchow’s triad, is thought to contribute to thrombosis. Therefore, a strong antiplatelet treatment is needed.

 

19.    The amount of insulin secreted from the pancreas is larger when glucose is taken orally than injected. What is the name of the group of hormones related to this physiological mechanism?

n  Answer：Incretin(GIP、GLP-1)

n  Comment：When glucose is absorbed from the mucous membrane of the digestive tract, incretins are secreted and thereby insulin is secreted from the pancreas. When glucose is taken intravenously, incretins are not secreted

 

20.    Tinnitus or otalgia, caused by a change in barometric pressure can be prevented or improved by swallowing as seen in the passengers sucking on hard candy when flying. What is the name of the nerve most related to this mechanism?

n  Answer：Mandibular nerve(V₃) or tensor veli palatini muscle nerve

n  Comment：Swallowing cause contraction of tensor veli palatini, innervated by the mandibular nerve, and help regulate the auditory tube function of ventilating the middle ear space and adapting to environmental air pressure change.

 

 

 

 

II.    Flip Quiz

1.       A 59-year-old man presented with complaints of weight gain and edema.  Answer the increase / decrease of the following examination findings in this patient.　【Picture is deleted】

①    K⁺

②    ACTH

③    Blood glucose

n  Answer： ① Decreased ② Increased ③ Increased

 

2.       Show the order of blood test findings in the recovery from iron deficiency anemia by means of administrating iron.

①      Serum ferritin

②      Reticulocyte

③      Serum iron

n  Answer：② ⇒ ③ ⇒ ①

n  Comment：In iron deficiency anemia, the value of reticulocytes is preferentially restored because iron is first used to improve anemia. After that, when the administration of the iron preparation is continued, the serum iron recovers and finally the surplus iron is stored in the liver as ferritin. Therefore, treatment of iron deficiency anemia is carried out until recovery of serum ferritin.

 

3.       According to the following examination results, what is the residual volume?

Vital capacity 4000 ml, tidal volume 500 ml, inspiratory reserve volume 2500 ml, functional residual capacity 2500 ml

n  Answer：1500 ml

 

4.       Which of the following diseases show this type of audiogram. Choose 2 answers.【Picture is deleted】

①      Acute otitis media

②      Meniere disease

③      Benign paroxysmal vertigo

④      Vestibular neuritis

⑤      Traumatic eardrum perforation

⑥      Sudden deafness

⑦      Poisoning of aminoglycosides

⑧      Acoustic trauma

n  Answer：①、⑤

n  Comment：AB(air-bone) gap positive patients show conductive hearing impairment. It is caused by the disease in external and middle ear, so ① and ⑤ are correct. ②,⑥,⑦ and ⑧ show sensorineural impairment. ③and ④ don’t cause hearing impairment.

 

 

5.       Choose three elements of Virchow’s triad that cause thrombus formation.

①      Vascular endothelial cell disorder

②      Abnormal blood flow

③      Pancytopenia

④      Increased cardiac output

⑤      Systolic hypertension

⑥      Hypercoagulability

n  Answer：①・②・⑥

 

6.       Rearrange the following statements related to the process of alcoholic hypoglycemia in correct order.

①      Reduced activity of LDH

②      Lack of oxaloacetate

③      Increased production of NADH

④      Decreased activity of gluconeogenesis

n  Answer：③ → ① → ② → ④

n  Comment：First, NADH is produced by dehydrogenation of alcohol by ADH. This reduces the conversion efficiency of lactic acid to pyruvic acid by LDH in the cytoplasm and the amount of oxaloacetate decreases. Oxaloacetic acid is an important substrate for gluconeogenesis, and the reaction of gluconeogenesis is reduced by the decrease of substrate.

 

7.       A 31 year-old man was admitted to the hospital with abdominal pain and vomiting. He ate a rice ball three hours ago during hill climbing. He has a sharp wound on his hand. Which of the following gram stain is most likely the pathogenic bacteria?　【Picture is deleted】

n  Answer：④

n  Comment：

If a patient touch food with his wounded hands, staphylococcus aureus attaches to the food. Staphylococcus aureus produces enterotoxin in the food.

Food poisoning due to staphylococcus aureus has the shortest incubation period in the bacterial food poisoning. Enterotoxin from staphylococcus aureus is heat resistance, so before meals heating is insufficiency.

 

 

 

 

 

 

 

 

 

 

 

8.       Choose three of the following diseases that show wide QRS in the electrocardiogram.

①      Atrioventricular regression tachycardia (AVRT)

②      Premature ventricular contraction (PVC)

③      Manifesting WPW syndrome

④      Atrioventricular block

⑤      Bundle branch block

⑥      Atrial fibrillation (AF)

n  Answer：②・③・⑤

n  Comment：Wide QRS refers to the state where the QRS wave is greater than 0.10 seconds in the electrocardiogram. This occurs when excitation is conducted to the ventricle without going through a normal stimulation conduction system. That is, ② which generates ectopic stimulation in the ventricle, ③ via the accessory conduction path ③, abnormal conducting system ⑤ is correct.

 

9.       Which of the following diseases cause whitish stool? Choose three answers.

①      Hypertrophic pyloric stenosis

②      Biliary atresia

③      Autoimmune hemolytic anemia

④      Pancreatic head carcinoma

⑤      Primary biliary cirrhosis(PBC)

⑥      Ischemic colitis

n  Answer：②・④・⑤

n  Comment：

Excretory disorder of bile to intestine cause whitish stool, so the disease which cause stenosis or closure of biliary duct are answers.

②：Biliary atresia often causes closure of bile duct at hepatic portal section.

④：Pancreatic head carcinoma infiltrates into common bile duct and causes obstructive jaundice.

⑤      ：PBC causes chronic non-suppurative destructive cholangitis (CNSDC) and destroys bile duct.

 

 

 

 

 

 

 

 

 

 

 

 

 

10.    Which of the following cause hydramnios? Choose three answers.

①      Pregnancy complicated with diabetes mellitus

②      Urinary obstructive of fetus

③      Premature rupture of membrane

④      Spina bifida

⑤      Congenital esophageal atresia

⑥      Oral medication of NSAIDs

n  Answer：①・④・⑤

n  Comment

① In diabetes mellitus, a rise of urinary osmotic pressure of fetus causes transference of water to renal tubules and increases production quantity of amniotic fluid in fetal kidney.

④ In the open lesion of fetus, body fluid leaks in amniotic fluid.

⑤ Occlusion of digestive tract causes malabsorption of amniotic fluid.

② In fetal urinary organs, dysplasia of kidney or occlusion of urinary tract cause disability of production and excretion of amniotic fluid.

③ In PROM, amniotic fluid is excretion and amo9unt of it decreases.

⑥ NSAIDs inhibits production of amniotic at fetal kidney.

 

11.    Which of the following are contraindication to MR vaccination. Choose two answers.

①      After splenectomy

②      Di George syndrome

③      Ventricular septal defect

④      Type 1 diabetes mellitus

⑤      X-linked severe combined immunodeficiency disease(X-SCID)

⑥      Cretinism

n  Answer：②・⑤

n  Comment：Di George syndrome and X-SCID cause immune deficiency of T cell, so injection of live-virus vaccine causes severe side effect.

 

12.    Choose three human autosomal chromosome which include smallest number of gene.

n  Answer：13,18,21

 

13.    Choose 3 of the following that cause systolic ejection murmur.

①      Aortic regurgitation(AR)

②      Aortic valve stenosis(AS)

③      Dilated cardiomyopathy(DCM)

④      Ventricular septal deficiency(VSD)

⑤      Anemia

⑥      Diabetes(DM)

n  Answer：①・②・⑤

14.    Which of the following findings are observed in patients with infarction of cerebellar hemisphere?　Choose two pictures.【Picture is deleted】

n  Answer：⑤・⑥

n  Comment：

Infarction of hemisphere of cerebellum mainly causes adiadochokinesis, dysmetria, dysarthria, intention tremor and so on.

⑤：Dysmetria

⑥：Adiadochokinesis

①：Horizontal rotating nystagmus

②：Circumduction gait

③：Romberg sign positive

④：Drunken gait

 

15.    There are three types of twin pregnancy, Monochorionic monoamniotic(MM) twins, Monochorionic Diamniotic(MD) twins and Dichorionic Diamniotic(DD) twins. Choose the most likely type of twins for each of the following cases.

※    If the answer is MM twins, please write A.

※    If the answer is MD twins, please write B.

※    If the answer is DD twins, please write C.

①      Separation of fertilized ovum five days after fertilization.

②      Each of two ovulated ova are fertilized by spermium

③      Fertilized ovum is separated ten days after fertilization

n  Answer: ① B ② C ③ A

n  Comment

Ø  In three days after fertilization, differentiation of fertilized ovum to trophoblast doesn’t arise, so each fertilized ovum has placenta and amnion.

Ø  In four to seven days after fertilization, differentiation of fertilized ovum to trophoblast is completed, so both fertilized ova share a placenta. Because development of amnion doesn’t arise, each ovum has amnion.

Ø  Eight and more days after fertilization, differentiation of trophoblast and development of amnion are completed.

 

 

III.Time Attack

①     　　　　　　　　　　　　

1.       Phrenic nerve branches from the thoracic cord.

n  Answer：False

 

 

2.       Thyroid hormone production is enhanced by excess iodine uptake.

n  Answer：False

n  Comment：Excessive iodine uptake inhibits Pendrin which transports iodine to the follicular cavity. This is called Wolff-Chaikoff effect. However, this effect lasts only 10 to 14 days.

 

3.       In CO2 narcosis, bicarbonate ion in blood decreases.

n  Answer：false

 

4.       The higher the tympanic impedance, the better the transmission of sound waves to the inner ear.

n  Answer：false

n  Comment：As the impedance becomes higher, sound waves are more likely to be reflected, so that sound waves are less likely to be transmitted to the inner ear. This statement is wrong also because compliance is the reciprocal of the impedance.

 

5.       Which factors are released from mitochondria in the intrinsic pathway of apoptosis?

P)     Fas ligand

Q)    TNF-α

R)     Cytochrome C

S)      Coenzyme Q

n  Answer：R

n  Comment：Mitochondrial injuries release cytochrome c. This factor activates caspase, an enzyme involved in apoptosis.

 

6.       Which is not included in the regulation factor of oxygen supply to the tissue?

P)     Cardiac output

Q)    Hemoglobin

R)     Venous reduced hemoglobin

S)      Arterial Oxygen Saturaation

n  Answer：R

n  Comment：Oxygen supply is calculated by cardiac output × arterial oxygen content. The arterial blood oxygen content is obtained by (1.34 × Hb × SaO 2 + 0.003 × PaO 2) × 10. 1.34 is the volume of oxygen (ml) bonded per 1 g of Hb, and 0.003 is the coefficient representing the solubility of oxygen.

 

 

 

 

 

 

 

 

7.       When does serum ALT start to increase rapidly in hepatitis B?

P)     HBe seroconversion

Q)    HBs antigen positive

R)     HBV-DNA positive

S)      IgM-HBc antibody positivve

n  Answer：P

n  Comment：HBe antibody suppresses CD8⁺ T cells. In HBe seroconversion, depletion of CD8⁺ T cells due to depletion of HBe antigen results in hepatocellular injury and ALT as a deviation

 

8.       Which malignancy is associated with pathogens of Africa type Burkitt lymphoma?

P)     Nasopharyngeal carcinoma

Q)    Hepatocellular cancer

R)     Kaposi sarcoma

S)      Stomach cancer

n  Answer：P

n  Comment：100% EBV is detected in Africa type Burkitt lymphoma. It is nasopharyngeal cancer that is associated with this pathogen.

 

9.       Which electrocardiogram change is recognized immediately after the onset of acute myocardial infarction?

P)     Negative T wave

Q)    Abnormal Q wave

R)     ST segment elevation

S)      T wave elevation

n  Answer：S

n  Comment：Hyperacute T wave is a finding observed within minutes after onset. ST rise is several hours later, abnormal Q wave is within 12 hours, negative T wave is several days after onset.

 

10.    Which is the correct mechanism of ACE inhibitors at the treatment for chronic heart failure?

P)     Decreased in blood pressure

Q)    Increase in renin activity

R)     Suppression of the interstitial remodeling

S)      Inhibition of sympathetic activity

n  Answer：R

n  Comment：The therapeutic effect of ACE inhibitor on chronic heart failure is not due to hypotensive action but by inhibition of myocardial remodeling and interstitial remodeling.

 

 

 

 

 

11.    Which lipids do not require micelle formation in the cause for absorption?

P)     Long chain fatty acid

Q)    Medium chain fatty acid

R)     Free cholesterol

S)      Vitamin D

n  Answer：Q

n  Comment：Micelle is a form required for lipid to pass through the static water layer on the intestinal epithelial surface.

 

12.    What is the name of the cavity through which the surgery of pituitary gland is performed?

n  Answer：Sphenoid sinus

 

13.    What is the electrolyte that has to be kept high in concentration in the perfusate to stop the heart during cardiac surgery?

n  Answer：potassium

Comment：Hyperkalemia must be diagnosed and treated quickly because it can lead to cardiac arrest. However, in case of a heart surgery, hyperkalemia is useful for stopping the heart during the surgery.

 

14.    What is the bacterium defined as Clostridium difficile species that produces toxin and causes tonic convulsion?

n  Answer：Clostridium tetani

n  Comment：Tetanospasmin inhibits elimination of inhibitory neurotransmitter.

 

15.    What is the physiologically active substance secreted from the placenta and keeps the fetus arterial duct opening?

n  Answer：prostaglandin E₁

 

16.    A certain drug inhibits reabsorption of glucose at the proximal tubule and is effective for diabetes mellitus. What receptor is inhibited by this drug?

n  Answer：SGLT2

n  Comment：

As a side effect, this drug can cause urinary tract infection due to high concentration of the glucose and dehydration induced by high osmotic pressure of primitive urine. In particular, dehydration of patient with diabetes mellitus can cause brain infarction.

 

17.    In order to elongate nucleotide, what does DNA polymerase require?

n  Answer：RNA primer

 

 

 

 

18.    A 48 year-old woman with breast cancer complains the limitation in upper limb lifting after surgery. Which nerve might be injured during the surgery?

n  Answer：long thoracic nerve

n  Comment：Serratus anterior muscle, which forms the lateral side of the breast is innervated by the long thoracic nerve. The muscle is essential for anteversion of the arm and keep the scapula pressed against the thorax.

 

19.    What is the component of arterial blood gas that is not stable in diffusion disorders but increases in alveolar hypoventilation?

n  Answer：carbon dioxide

n  Comment：According to the Fick’s law of diffusion, CO2 is more soluble than O2 and thereby diffuse easily. When a patient has an impaired diffusion of the lungs, arterial CO2 pressure do not increase.

 

20.    A patient has been suffering from small cell lung carcinoma. He has noticed disturbance in gait and muscle weakness. What is the transporter that is most likely impaired in this patient?

n  Answer：voltage-gated(dependent) calcium channel(VGCC / VDCC)

n  Comment：This patient is most likely to be diagnosed Lambert-Eaton syndrome.

 

21.    What is the enzyme secreted by the kidneys where serum concentration is low in patients with primary aldosteronism and high in patients with secondary aldosteronism?

n  Answer：Renin

n  Comment：In secondary aldosteronism, the renin-angiotensin-aldosterone system activates to complement the decreased renal blood flow(or GFR)

 

22.    In horizontal eye movement, which nerve fibers conduct impulses from parapontine reticular formation(PPRF) to the nucleus of the oculomotor nerve?

n  Answer：Medial longitudinal fasciculus(MLF)

n  Comment：MLF syndrome is a disorder that the affected eye, which is the opposite side of impaired MLF, shows impairment of adduction.

 

23.    After death, blood does not generally coagulate. What factor inhibits coagulation?

n  Answer：tissue plasminogen activator(t-PA)

n  Comment：Collapse of vascular endothelial cells causes releasing t-PA, which activates plasminogen activator.

 

24.    What is the common substance which is increased in the blood in obstructive jaundice, normal pregnancy and adolescence?

n  Answer：ALP(Alkaline phosphatase)

 

25.    Name of the cell which releases the factor that causes involution of Muller duct in the fetus with 46XY.

n  Answer：Sertoli cell

 

②     　　　　　　　　　　　　

1.       Diplopia occurs due to ophthalmic nerve failure.

n  Answer：False

 

2.       Insulin is administered orally.

n  Answer：False

n  Comment：Since insulin is a peptide hormone, it is decomposed by proteolytic enzymes when administered orally.

 

3.       Urinary bilirubin is positive in hemolytic anemia.

n  Answer：false

n  Comment：It is indirect bilirubin that increases in hemolytic anemia. Indirect bilirubin is lipid soluble so it can not be filtered through glomeruli. Therefore, urinary bilirubin is negative.

 

4.       Biliary vomiting occurs in hypertrophic pyloric stenosis.

n  Answer：false

n  Comment：In the narrowing of the pylorus, the bile flowing from the papilla of  Vater into the intestinal tract is less likely to flow back into the stomach. Therefore, the bile is not included in the vomit.

 

5.       Which of the following decreases with aging?

P)     Systolic blood pressure

Q)    Diastolic blood pressure

R)     Pulmonary residual volume

S)      Serum creatinine

n  Answer：Q

n  Comment：Elastic fibers in elastic blood vessels are decreased with aging. Systolic blood pressure rises, but diastolic blood pressure decreases due to decreased Windkessel function.

 

6.       Which factor triggers hyperkalemia?

P)     Discontinuation of α blocker

Q)    Discontinuation of β blocker

R)     Decrease in body temperature

S)      Administration of sodium bicarbonate

n  Answer：Q

n  Comment：

Q) β agonist transfers potassium into cells.

S) Alkalization of blood by sodium bicarbonate similarly moves potassium into cells.

 

 

7.       Rituximab is effective for which one of the following disease?

P)     Diffuse large B-cell lymphoma

Q)    Mycosis fungoides

R)     Classical Hodgkin lymphoma

S)      Acute lymphocytic leukemia(ALL)

n  Answer：P

n  Comment：Rituximab is an anti-CD20 monoclonal antibody. Since CD20 is a B cell marker, P) is correct. Hodgkin lymphoma is also a B cell type tumor, but classical Hodgkin lymphoma is negative for CD 20 (CD 15, CD 30 is positive).

 

8.       Which test is useful even in patients taking insulin therapy?

P)     C-peptide(CPR)

Q)    HOMA-β

R)     HOMA-R

S)      Insulin secretion index(IRI)

n  Answer：P

n  Comment：Q), R), S) are influenced by blood insulin level, therefore, the test items are not accurate in patients taking insulin therapy.

Since C peptide is produced by degrading proinsulin, the ability of insulin secretion by the pancreas can be evaluated even under insulin administration.

 

9.       Which radiopharmaceuticals is useful in evaluating myocardial viability and shows enhancement of accumulation to the ischemic myocardium?

P)     ¹⁸F-FDG

Q)    ¹²³I-BMIPP

R)     ^99mTc-Pyrophosphoric acid

S)      ²⁰¹TICI

n  Answer：P

n  Comment：

Ø  P) ¹⁸F-FDG is a radiopharmaceutical that reflects carbohydrate metabolism. Oxygen-free glycolytic system is accelerated during ischemia and increased accumulation is observed. ¹⁸F-FDG is useful for evaluating myocardial viability (survival evaluation).

Ø  Q) It is a radiopharmaceutical reflecting fatty acid metabolism. Oxygen is necessary to produce ATP from fatty acids, therefore, accumulation is less observed during ischemia.

Ø  S) shows the same kinetics as K + and is taken up into the cell via Na + / K + ATPase. During ischemia, accumulation is less observed as ATP decreases.

 

 

 

 

10.    Which pharmaceutical is effective for a patient with acute decompensated heart failure who is taking a β blocker?

P)     Dobutamine

Q)    Milrinone

R)     Donepezil

S)      Adrenaline

n  Answer：Q

n  Comment：Since milrinone is an agent that increases the intracellular cAMP concentration without inhibiting PDE III, not via β receptor, it is an effective prescription for patients with acute decompensated heart failure who are taking β-blockers

 

11.    Which vitamin is poorly absorbed in patients with insufficient bile secretion?

P)     Vitamin B₁

Q)    Vitamin B₆

R)     Vitamin D

S)      Vitamin C

n  Answer：R

n  Comment：Since vitamin D is a fat-soluble vitamin, it requires micelle formation by bile acid for absorption.

 

12.    What is the main component of amino acid in collagen fibers

n  Answer：glycine

n  Comment：The primary structure in collagen consists of repetitious amino acid sequence of [-Gly-X-Y-].

 

 

13.    What is the name of the mechanism by which the cell’s response to a hormone reduces due to the chronic exposure to the hormone?

n  Answer：down regulation

 

14.    What is the condition in which deoxyhemoglobin in capillary vessels increases up to 5g/dL or more?

n  Answer：Cyanosis

 

15.    What is the organ which metabolizes ammonia by administration of BCAA in a patient with hepatic cirrhosis?

n  Answer：Skeletal muscle

n  Comment：Ammonia combines with glutamate produced in skeletal muscle and is changed into glutamine by glutamine synthetase.

 

16.    What is the substance which is produced in follicular epithelial cell and becomes thyroid hormone by adding iodide ion to tyrosine residue?

n  Answer：Thyroglobulin

 

17.    The expression of allele in a certain genetic locus differs from person to person What is this phenomenon?

n  Answer：Genome imprinting

n  Comment：Genome like this can express only either allele. If that genome takes irreversible damage, child may suffer from the hereditary disease. Prader-Willi syndrome is notorious, whose responsible chromosome causing the disease is No.15, derived from father.

 

18.    What is the name of the transporter that causes over drive suppression induced by higher firing rate of sinoatrial node is hyperstimulated?

n  Answer：Na⁺/K⁺ATPase

n  Comment：Na⁺/K⁺ATPase pumps 3 Na+ outside of the cell for every 2 K+ pumped into the cell. This produces the electrical current outward and inhibits the production of action potential.

 

19.    In the cardiac myocytes with ischemia, generation of action potential is suppressed（ischemic preconditioning ）. This is due to deficiency of a substance in the cell. What is the name of the substance in the cell that causes this phenomenon?

n  Answer：ATP

n  Comment：ATP sensitive potassium channel opens when the concentration of ATP lowers in a cell. It produces the electric current outward and the firing rate of the cell decreases.

 

20.    What is the superficial reflex of which the center is located at S3 ～ S5?

n  Answer：Anal reflex

 

21.    What is the name for the diastolic murmur that is associated with pulmonary hypertension?

n  Answer：Graham-Steel murmur

n  Comment：The Graham steel murmur occurs in diastole due to a high velocity regurgitation across the pulmonary valve, which is usually a consequence of pulmonary hypertension

 

22.    A patient is conscious but has quadriplegia and bulbar paralysis. The intact movements are vertical eye movement and blinking. What is the name of the structure that is most likely damaged?

n  Answer：Pons

n  Comment：Locked in syndrome, caused by impairment of pons, is a condition in which a patient is conscious but cannot move. The patient’s nucleus of oculomotor nerve in the midbrain is intact, thereby he is able to move the eyes vertically.

 

23.    Esophagus achalasia is a disorder that shows dysphagia and diminished esophageal peristalsis. What is the structure impaired in the patients with this disorder?

n  Answer：Auerbach’s plexus

n  Comment：Auerbach’s plexus regulates the peristalsis of smooth muscles in the gastrointestinal tract.

 

 

24.    Pancytopenia due to liver cirrhosis is related to hyperfunction of which organ?

n  Answer：Spleen

n  Comment：Portal hypertension leads to congestion of blood in the splenic vein, resulting in splenomegaly and destruction of blood cells.

 

25.     Paroxysmal nocturnal hemoglobinuria(PNH) is a disease caused by hyoersensitivity to complements due to lack of CD55 and CD59. What is the substance in the cell membrane impaired in patients with PNH?

n  Answer：Phosphatidylinositol

n  Comment：PNH patient has GPI deficiency.

 

 

③     　　　　　　　　　　　　

1.       Pyramidal tract disorder causes enhancement of muscle tonus.

n  Answer：True

 

2.       In type 1 diabetes, the value of serum C peptide increases.

n  Answer：False

n  Comment：In type 1 diabetes, the absolute deficiency of insulin is present, so the C peptide from cleavage of proinsulin decreases.

 

3.       In tumors with SDH gene mutations, VEGF expression is enhanced.

n  Answer：true

n  Comment：Hypoxia-inducible factor (HIF-1α) is ubiquitinated by VHL, α-ketoglutarate, etc., while it is stabilized by succinic acid。Therefore, succinate dehydrogenase (SDH) mutation increases succinic acid, and HIF-1α stabilizes, thereby increasing VEGF expression.

 

4.       The internal intercostal muscle acts mainly in resting exhalation.

n  Answer：false

n  Comment：During resting exhalation, exhalation occurs only by relaxation of the diaphragm / intercostal muscle. Internal intercostal muscle is used during effort exhalation.

 

5.       In which of the following cases does urinary Na excretion amount shows less than 20 mEq / L?

P)     Overdose of diuretic

Q)    Diarrhea

R)     SIADH

S)      Addison’s disease

n  Answer：Q

n  Comment：With diarrhea, Na and water reabsorption in the kidneys is accelerated by loss of circulating plasma volume.

6.       Which in the substance whose production is reduced with the aspirin dilemma?

P)     LTB₄

Q)    PGI₂

R)     TXA₂

S)      PGE₂

n  Answer：Q

n  Comment： Aspirin dilemma refers to a phenomenon that a low dose of Aspirin shows antiplatelet behavior by inhibiting TXA2 production. When a high dose of Aspirin is administered, antiplatelet behavior is suppressed for PGI2 production is reduced.

 

7.       Which bacteria can cause endotoxin shock?

P)     Staphylococcus aureus

Q)    Escherichia coli

R)     Streptococcus pyogenes

S)      Clostridium perfringens

n  Answer：Q

n  Comment：Endotoxin (endotoxin) is distributed on the cell wall of Gram negative bacteria.

P, R and S are all Gram positive bacteria.

 

8.       Which one of the following diseases does not cause an increase in blood ALP?

P)     Basedow disease

Q)    Obstructive jaundice

R)     Pregnancy

S)      Myocardial infarction

n  Answer：S

n  Comment：

Ø  P) In Basedow disease bone resorption is accelerated, bone type ALP rises.

Ø  Q) Since ALP is also a biliary tree enzyme, it is elevated in biliary tract diseases.

Ø  R) Placental ALP increases in pregnancy.

Ø  S) ALP is not an escape enzyme in myocardial infarction.

 

9.       Which condition may cause U wave increase in the electrocardiogram?

P)     Serum Ca: 13mg/dL

Q)    Serum K: 7.0mEq/L

R)     Serum Ca: 6.0mg/dL

S)      Serum K: 2.0mEq/L

n  Answer：S

n  Comment：U wave rise is one of the characteristic changes in ECG in hypokalemia. Negative U waves may be found in ischemic heart disease.

 

10.    Which of the following becomes the indication for emergency surgery?

P)     Coronary vasospastic angina

Q)    Cardiogenic cerebral embolism

R)     False lumen open aortic dissection(Stanford A)

S)      Unruptured aortic aneurysm

n  Answer：R

n  Comment：Stanford A type aortic dissection has dissociation in the ascending aorta and emergency operation is performed for there is a high possibility of cardiac tamponade happening. However, in case of the false chamber obstructive type, options for conservative treatment is allowed.

 

11.    Which higher metabolism is active in Zone 1 than in Zone 3 in liver lobe of Rapaporto?

P)     Drug metabolism

Q)    Gluconeogenesis

R)     Alcohol metabolism

S)      Glycolysis

n  Answer：Q

n  Comment：Zone 1 is the portal region, Zone 3 is the central region, the partial pressure of oxygen is higher in the former. Therefore, mitochondria is also dominant in Zone 1, metabolism performed in ATP-dependent metabolism and mitochondria is dominated by Zone 1.

 

12.    What is the name of the muscle that originates at the coracoid process and bends the forearm upward toward the upper arm?

n  Answer：biceps brachii

n  Comment：The short head of the biceps brachii originates at the coracoid process and the long head originates at supraglenoid tubercle.

 

13.    What is the name of protein that monitors blood estrogen level and plays an important role in GnRH secretion from the hypothalamus?

n  Answer：kisspeptin

 

14.    The volume of myocyte can be increased by strength training. What is the name of this physiological change?

n  Answer：Hypertrophy

n  Comment：Muscle atrophy is the opposite concept of musccle hypertrophy. When muscles aren’t used, they rapidly begin to weaken and atrophy. The example of this would be the skeletal muscles atrophy after a long period of bed rest.

 

15.    What is the phenomenon called when engorgement of the jugular vein is found at inspiration phase in a patient suffering from constrictive pericarditis?

n  Answer：Kussmaul sign

 

16.    In the proximal tubule, what ion moves into the proximal cell with reabsorption of glucose?

n  Answer：Sodium

n  Comment：In the proximal tubule, glucose is reabsorbed through SGLT2. A new drug which target is this receptor is developed there days.

 

17.    A change of pH in the erythrocyte causes shift of oxygen dissociation curve. What is the name of this phenomenon?

n  Answer：Bohr effect

 

18.    When a patient with Diabetic ketoacidosis is injected with short-acting insulin, what electrolyte decreases in the blood?

n  Answer：Potassium

n  Comment： Insulin activates Na⁺/K⁺ATPase. Therefore. potassium ion in the blood is transported into the cell.

 

19.    Beta blockers and calcium channel blockers are contraindicated for pseudo ventricular tachycardia(VT). This is because they slow the electric conduction of which part of the heart?

n  Answer：atrioventricular node

n  Comment：Beta blockers and calcium channel blockers have inhibitory effect on atrioventricular resulting in electric conduction via accessory pathway. This may cause clinical deterioration.

 

20.    Where does ovum go right after it is released from the ovary?

n  Answer：Abdominal cavity

n  Comment：As soon as the ovum is released from the ovary into the abdominal cavity, it is catched by the fimbria of fallopian tube and enters the fallopian tube.

 

21.    28 year-old man was admitted to the hospital because of femoral fracture due to a traffic accident. 5 days after his admission, he had hemiplegia and dysarthria. What is the mechanism for his neural disorder?

n  Answer：fatty embolism

n  Comment：Fat embolism is often seen in orthopedic patients after femoral fracture.

 

22.    A person with the visual acuity of 0.04 is able to distinguish the Landolt-C for 0.1 how many meters away from it?

n  Answer：2m

n  Comment：When a tested subject can point out the break of the largest C on test type 5m away from the chart, the subject has the visual acuity of 0.1. If the subject cannnot point out any beak of the Cs, he is allowed to get closer to the chart and calculate the visual acuity by using the formula 0.1*distance from the chart/5m.

 

23.    What is the organ which is supplied by the celiac trunk in adults but doesn’t derive from mesoderm?

n  Answer：Spleen

24.    In order to distinguish ovarian teratoma torsion from ectopic pregnancy, what hormone should be examined?

n  Answer：human chorionic gonadotropin(hCG)

n  Comment：hCG is positive in patients with ectopic pregnancy, but negative in patients with teratoma torsion.

 

25.    CPAP(continuous positive airway pressure) increases the lung volume at the end of passive expiration. What is this lung volume called?

n  Answer：Functional residual capacity

n  Comment：PEEP can increase ERV by recruiting alveoli which would have otherwise been collapsed. FRC is calculated by addition of residual volume to ERV.

 

 

④     　　　　　　　　　　　　

1.       Internal anal sphincter is innervated by the pudendal nerve.

n  Answer：False

n  Comment：Internal anal sphincter is dominated by parasympathetic nerve (pelvic splanchnic nerve).

 

2.       Gastrin secreted from G cells promotes contraction of lower esophageal sphincter and pyloric sphincter

n  Answer：False

 

3.       The activity of gluconeogenesis in hepatocytes is high in the central region of the hepatic lobule.

n  Answer：false

n  Comment：Liver lobule has high oxygen partial pressure in the portal region. Therefore, mitochondria are abundant in the portal vein area. Since gluconeogenesis requires ATP supplied from fatty acids, the activity of gluconeogenesis is higher in the portal region.

 

4.       Decompensated liver cirrhosis causes pancytopenia.

n  Answer：true

n  Comment：Portal hypertension causes blood to stagnate in the spleen and destruction of blood cell components is accelerated.

 

5.       Where is the distribution of approximately 65% of the total blood volume distributed?

P)     Capillary

Q)    Artery

R)     Vein

S)      Lung

n  Answer：R

n  Comment：Of the total blood volume, 65% is in the vein, about 10% is in the artery / heart, about 3% is in the capillary blood vessel and about 12% is distributed in the lung. Therefore veins are also called capacitance vessels.

6.       Which base is not affected in folate deficiency?

P)     Adenine

Q)    Uracil

R)     Thymine

S)      Guanine

n  Answer：Q

n  Comment：Folic acid is essential for synthesis of purine base (A · G). Regarding pyrimidine bases, thymine requires folic acid in the process of biosynthesis from uracil, but folic acid is unnecessary for uracil biosynthesis itself.

 

7.       O antigen is located in which part of bacterium?

P)     Flagella

Q)    Cell wall

R)     Capsule

S)      Ribosome

n  Answer：Q

n  Comment：O antigen is derived from cell wall LPS, H antigen is flagellum, K antigen is from capsule.

 

8.       Which electrolyte decreases in DiGeorge syndrome?

P)     Na⁺

Q)    Ca²⁺

R)     K⁺

S)      Mg²⁺

n  Answer：Q

n  Comment：In DiGeorge syndrome, hypoplasia of the parathyroid and thymus occurs.

 

9.       Which disease causes PQ shortening?

P)     Hypocalcemia

Q)    Propranolol

R)     Manifesting WPW syndrome

S)      Atrioventricular block

n  Answer：R

n  Comment：In Manifesting WPW syndrome, stimulation from the accessory conduction path not through the AV node is conducted to the ventricle. This will shorten the PQ interval because there is no atrioventricular delay.

 

 

 

 

 

10.    Which of the following is expected from the ECF below?

P)     Type 1st atrioventricular block

Q)    Wenkebach type 2nd atrioventricular block

R)     Molitz type 2nd atrioventricular block

S)      Complete atrioventricular block

n  Answer：Q

n  Comment：In Wenkebach type 2 QRS wave drops after gradual extension of PQ interval.

 

11.    Which of the following increases in aspirin asthma?

P)     IgE

Q)    Prostaglandin

R)     FEV1%

S)      Leukotriene

n  Answer：S

n  Comment：Aspirin asthma is not allergic. It is caused by relative hyperproduction of SRS-A (Slow Reacting subbstance of Anaphylaxis, LTC 4, LTD 4, LTE 4) by COX inhibition. Symptoms are often severe.

 

12.    What is the name of the substance produced by osteoblasts that protects bone from resorption by binding to RANKL?

n  Answer：Osteoprotegerin

 

13.    What is the name of the substance generated by glutaminase in the kidney and plays an important role in excretion of protons?

n  Answer：Ammonia(NH₃)

 

14.    Microtubules repeat slow growth and rapid shrinkage. What is this characteristic process called?

n  Answer：Dynamic instability

 

15.    What is the hormone secreted from ventricle and increases due to an increase in venous return?

n  Answer：brain natriuretic peptide(BNP)

 

16.    Which part in the brain causes episode amnesia in the Mild Cognitive Inpairment(MCI)?

n  Answer：Hippocampus

 

17.    What is the name of the phenomenon which makes the timing of genetic expression earlier when inheriting a certain genome?

n  Answer：Anticipation

 

 

 

18.    A patient has been suffering from paraplegia after the replacement of thoracic aortic aneurysm. During the surgical treatment, the dominant thoracolumbar segmental artery was occluded. What is the artery called?

n  Answer：The artery of Adamkiewicz

n  Comment：The artery of adamkiewicz arises from the 9^th ~ 12^th intercostal artery and it supplies blood to the anterior part of the spinal cord. The replacement surgery of descending aorta may cause occlusion of the artery.

 

19.    Thyroid hormone activate Uncoupled protein-1(UCP-1) and decreases the concentration gradient of what electrolyte?

n  Answer：Protons (H⁺)

n  Comment：Uncoupling of oxidative phosphorylation and electron transport system promotes re-oxidation of NADH・FADH2 and thereby activates TCA cycle, which subsequently produces heat.

 

20.    Administration of what electrolyte is useful for the treatment of ventricular fibrillation subsequent to Torsade de pointes?

n  Answer：Magnesium (sulfate)

n  Comment：Magnesium decreases the resting membrane potential and thereby inhibits depolarization of the cell. Note that patients with renal disorder should not be administered magnesium.

 

 

21.    A high temperature period is observed for more than one month in a 29-year-old woman What is the most likely the diagnosis?

n  Answer：Pregnancy

n  Comment：The high temperature phase of a woman’s basal body temperature is created by progesterone secreted from the corpus lutenum. When pregnancy occurs, hCG is produced and it maintains the function of corpus lutenum. When you examine female patient in a reproductive age group, you should always keep in mind to check whether the patient is pregnant or not.

 

22.    What type of involuntary movement is provoked by an impairment of glutamatergic neurons of the basal ganglia?

n  Answer：Ballism

n  Comment：Rhw glutamatergic nerves in the basal ganglia exist only in the subthalamic nucleus.

 

23.    What electrolyte is often deficit in patients with malabsorption?

n  Answer：Ca²⁺

n  Comment：Malabsorption is a disorder that fatty acids and calcium ions form salt in the gastrointestinal tract, thereby calcium is not absorbed.

 

24.    What is the name of the receptor high in number in the liver and increases frequency of gallstone during pregnancy.

n  Answer：LDL receptor

25.    What is the name of the method which can detect specific arrangement of DNA to prove HTLV-1 infection?

n  Answer：Southern blotting

 

 

⑤     　　　　　　　　　　　　

1.       Autonomic nerves to vascular smooth muscles are parasympathetic dominant.

n  Answer：False

n  Comment：The parasympathetic nerve is not directly distributed in the vascular smooth muscle. The parasympathetic nerve distributed in vascular endothelial cells promotes the production of nitric oxide (NO) in vascular endothelial cells and causes the relaxation of vascular smooth muscle.

 

2.       Secretin contracts the gall bladder and relaxes the sphincter of Oddi.

n  Answer：False

 

3.       Catamenial pneumothorax rarely occurs under taking oral contraceptives.

n  Answer：true

n  Comment：Menstruation related pneumothorax is a disease in which ectopic endometrium exists in the diaphragm. Oral contraceptives are also called "pseudopregnancy therapy", and ectopic endometrium does not fall off as blood progesterone concentration increases.

 

4.       When hot water is injected into the right ear canal, a leftward nystagmus occurs。

n  Answer：false

 

5.       Which of the following is not correct as the effect of aspirin administration?

P)     Decrease in glomerular filtration rate(GFR)

Q)    Induction of stomach / duodenal ulcer

R)     Increased body heat production

S)      Induction of asthma

n  Answer：R

n  Comment：

P) Detection of a decrease in glomerular filtration amount (GFR) in dense plaque causes prostaglandin activation and promotion of renin secretion by activation of COX-2. Therefore, aspirin decreases GFR.

R) Aspirin inhibits PGE 2 production and suppresses body heat production.

S) Inhibition of COX enhances relative leukotriene production.

 

 

 

 

 

6.       Which of the following can cause hypertonic hyponatremia?

P)     Congestive heart failure

Q)    SIADH

R)     Diabetes mellitus

S)      Addison’s disease

n  Answer：R

n  Comment：In order to increase the osmotic pressure in hyponatremia, effective osmotic substances other than Na + must be loaded. Among the choices, In patients with DM, a large amount of glucose is present in the blood, which can form effective osmotic pressure.

 

7.       Which antibiotics is recommended to administer sufficient amount once a day?

P)     Penicillins

Q)    Macrolide

R)     New quinolone series

S)      Tetracyclines

n  Answer：R

n  Comment：New quinolone and aminoglycoside antibiotics are concentration-dependent antibiotics, the higher the maximum blood concentration, the more effective the drug. On the contrary, the antimicrobial agent of other options is time-dependent, and the longer the time the blood concentration is MIC or more, the higher the effect is. That is, frequent administration is better for their drugs.

 

8.       Bullous pemphigoid was observed in patients undergoing diabetes treatment. Which pharmaceutical has this serious side effect?

P)     DPP-4 inhibitor

Q)    Thiazolidine

R)     Giguanide

S)      Sulfonylurea

n  Answer：P

n  Comment：It was discovered in recent years as a serious side effect of DPP-4 inhibitor, and the Ministry of Health, Labor and Welfare is ringing a warning bell.

 

9.       Which of the following items in blood test changes within 4 hours after onset of acute myocardial infarction?

P)     ESR

Q)    CRP

R)     ALT

S)      Troponin T

n  Answer：S

 

 

10.    Which of the following may cause prolongation of the QRS wave in the electrocardiogram?

P)     Primary hyperparathyroidism

Q)    Diarrhea

R)     Paroxysmal supraventricular tachycardia(PSVT)

S)      Administration of ACE inhibitor

n  Answer：S

n  Comment：ACE inhibitors may cause hyperkalemia. In hyperkalemia, tent-like T-wave · QRS wave extension, P wave disappearance etc. are observed.

 

11.    Which finding is NOT observed in hyperventilation syndrome?

P)     Orthopnea

Q)    Chvostek’s sign

R)     Cheyne-Stokes breathing

S)      Torso’s sign

n  Answer：R

n  Comment：In hyperventilation syndrome, positive charges bound to negative charged proteins are lost due to excess H + excretion. Therefore, free Ca²⁺(calcium ions) in blood bind instead of the lost positively charged (H +). In this way, free calcium ions, which are physiologically functional are lost, causing hypocalcemia.

 

12.    Continuous partial contraction is recorded in the skeletal muscles even during resting state. What is this contraction called?

n  Answer：Muscle tone

n  Comment：Injury of upper motor neuron causes hypertonia. Injury of lower motor neuron causes hypotonia.

 

13.    M1macrophage produces nitric oxide by means of iNOS. What is the substrate for iNOS?

n  Answer：arginin

 

14.    What is the phenomenon that systolic blood pressure decreases below 10mmHg in a patient suffering from cardiac tamponade?

n  Answer：Kussmaul pulse

 

15.    What is the chemical mediator causes systemic symptoms of cardiac myxoma?

n  Answer：Interleukin 6

 

16.    Which gram-negative spirillum may cause Guillain-Barre syndrome?

n  Answer：Campylobacter spp.

 

17.    Which hormone is secreted by small adipocyte and promotes insulin sensitivity of the cell?

n  Answer：Adiponectin

18.    A smoking woman has a higher risk of cardiovascular disorders when she takes birth control pill. This is due to what substance in the pill?

n  Answer：Estrogen

n  Comment：Estrogen has an anticoagulant effect. This effect becomes prominent when the vascular wall is damaged by smoking and might cause a thrombosis.

 

19.    A 41 year-old man who underwent sigmoid colectomy suffers from erectile dysfunction and dysuria. What is the nerve damaged in the surgery?

n  Answer：pelvic splachnic nerve / erectile nerve

n  Comment：Erection and urination are controlled by the parasympathetic pelvic splachnic nerve. Lymph dissection during sigmoid colectomy may damage the nerve.

 

20.    Injury of which cranial nerve causes difficulty in pronouncing labials?

n  Answer：Facial nerve

n  Comment：Labials are pronounced by orbicular muscle of mouth

 

21.    Unlike Adult hemoglobin, Fetal hemoglobin(HbF) is not able to bind to 2.3-BPG. This is due to a lack of a molecule that exists in Adult hemoglobin(HbA). What is the molecule?

n  Answer：β-globin

n  Comment：Fetus hemoglobin has a higher oxygen affinity due to the lack of 2,3-BPG binding site.

 

22.    6 year-old boy who put on an eye patch on his left eye for a long time is suffering from impaired eyesight which is resistant to visual acuity correction. What does occur on his left eye?

n  Answer：Amblyopia

Comment：Development of visual cortex by imaging on retina is necessary to develop normal vision. In patients with amblyopia, binocular vision is impaired, thereby the vision of the affected eye do not develop. The patient should receive appropriate treatment by age 10.

 

23.    Free iron catalyzes the active oxygen formation and causes cytopathy. What is the name of the active oxygen?

n  Answer：hydroxyl radicals

n  Comment：Free irons catalyze Fenton reaction and produce hydroxyl radicals. Free irons should be bound to blood protein, such as transferrin to be chemically stable.

 

24.    What is the substance which is produced from p53 and inhibits cell cycle?

n  Answer：p21

 

25.    Name the amino acid which combines A chain with B chain of insulin.

n  Answer：Cysteine