Repeated USMLE Questions Step 1- 159

A 43-year-old man presents to your clinic for a follow up after colon biopsy taken last week. He has a history of constipation and blood in stools for 6 months. Biopsy reveals colon cancer. After you told him the bad news, he looked down and told you that constipation was not that bad. He seeks more investigations because he does not think that he has cancer.

What is the emotional stage experienced by this patient at this time?

A- Denial

B- Anger

C- Bargaining

D- Depression

E- Acceptance






Answer

The first reaction to life-threatening news is denial. Some doctors go further with more investigations to confirm the diagnosis at the patient’s request. Other stages come after and end in acceptance of the condition and following treatment.

The correct answer is A

Repeated USMLE Questions Step 1- 158

A 48 year old man presents to the emergency room with severe headache and blurred vision. His blood pressure is 230/140. Ophthalmologic examination reveals blurred optic discs with indistinct margins. An intravenous drip of sodium nitroprusside is started.

What is the mechanism of action of this medication?

A- Alpha adrenergic antagonist

B- Beta adrenergic antagonist

C- Ganglion blocker

D- ACE inhibitor

E- Direct smooth muscle vasodilator

Answer:

Sodium nitroprusside is a direct smooth muscle vasodilator. It works directly on the large arteries to lower systolic blood pressure.

The correct answer is E 

Repeated USMLE Questions Step 1- 157

A 73 year-old man with a history of senile enlarged prostate presents to the emergency room complaining of repeated falls. His wife admits that during the past 3 weeks he has had unsteady gait, urinary incontinence and memory disturbances. His medical, surgical and family histories are unremarkable. He has never smoked or taken any recreational drugs. He drinks alcohol socially. His laboratory tests are all normal. A CT scan of the head shows slightly enlarged ventricles and slightly compressed gyri.

Repeated USMLE Questions Step 1 - 156

A 9 month-old boy is brought to the clinic by his mother who is concerned that the boy developed swelling in his right scrotum. On examination, there is a scrotal mass that disappears when pushing it back to the external inguinal ring. When the boy cries, the mass is felt again protruding out of the external inguinal ring.

What is the most likely etiology of this condition?

A-Defect in the inguinal canal
B-Defect in the pelvic floor
C-Patent processus vaginalis
D-Defective closure of tunica vaginalis
E-Undescended testis






Answer:

The most important cause of inguinal hernia in infants is patent processus vaginalis which fails to be obliterated after descending of testes. Persistent lumen of tunica vaginalis causes hydrocele, not hernias.

The correct answer is C

Repeated USMLE Questions Step 1 - 155

A 23-year-old woman presents to the clinic with a complaint of pain in her left breast since last night. She is breastfeeding her 1-week-old girl. On examination, her temperature is 99.8 F, her pulse is 88/min. and her blood pressure is 120/80. Local examination of the left breast reveals a localized soft tender 1-inch area. Her past medical, surgical and family histories are unremarkable. What is the most likely diagnosis?

A- A clogged milk duct

B- A breast abscess

C- Milk engorgement

D- Mastitis

E- Inflammatory carcinoma




Answer

This is a presentation of a clogged milk duct in which the mass is localized, tender, and not erythematous or firm. There is no fever or any signs of acute inflammation. There is also no signs or family history of cancer. Abscess occurs later if this mass is infected and no treatment applied. Milk engorgement results in generalized involvement of both breasts. A clogged milk duct is diagnosed mainly by exclusion.

The correct answer is A

Repeated USMLE Questions Step 1 - 154

A 73 year old man is brought to the emergency room for dizziness and nystagmus. Examination reveals loss of sensation on the left side of his face and the right side of his body. He has hoarseness of voice and drooping of his right eyelid. The right side of the face is drier than the left side. He is referred for CT scan on his head.

What is the site of lesion responsible for hoarseness of this patient?

A- Inferior cerebellar peduncle

B- Spinal nucleus of fifth cranial nerve

C- Nucleus Ambiguus

D- Lateral spinothalamic tract






Answer

Nucleus ambiguus contains the cell bodies of the nerves that innervate soft palate, larynx and pharynx. Lesions of the nucleus ambiguus affect one or more of nerve supply to these organs. Hoarseness of voice in this case is most probably due to defect of the innervation to the larynx caused by lesion of the nucleus ambiguus.

The correct answer is C

Repeated USMLE Questions Step 1 - 153

A 67 year old man is brought to the emergency room by his colleagues for a possible heart attack. One hour ago, he felt excruciating chest pain, shortness of breath and nausea. ECG shows elevation of ST segment in leads 11, 111 and aVF. Therapy is initiated and the patient starts feeling better. ER physician explains to the patient mechanism of action of different drugs used in the treatment.

Which of these drugs is responsible for rapid reperfusion in this patient?

A- Aspirin

B- tPA

C- Ticlopidine

D- Argatroban






Answer

tPA is the only drug of the above choices which mechanism of action is mainly reperfusion of the affected site.

The correct answer is B

Repeated USMLE Questions Step 1 - 152

A 17 year-old girl visits the clinic with her mother who is concerned that her daughter had not menstruated yet and her breast had not been significantly developed. She also notes that her daughter is color blind. The girl denies any sexual relationship or using any recreational drugs. Examination reveals normally appearing girl with small non-developed breasts. There is lack of pubic hair and her vagina and cervix are not fully developed. She is 5f5in tall and weighs 130 Ib. Cardiac, chest and abdominal examinations are unremarkable.

What is the most likely initial diagnosis?

A-Androgen insensitivity disorder

B- Early pregnancy

C- Kallmann’s syndrome

D- Kartagener’s syndrome

E- Turner’s syndrome

Answer






This patient has primary amenorrhea, delayed secondary sexual development and color blindness. All these features are characteristic of Kallmann’s syndrome. It is a hereditary disorder of GnRH synthesis. Androgen sensitivity disorder is characterized by the development of breasts and female external genitalia in an XY candidate. This patient has primary amenorrhea and under-developed secondary sexual characteristics which exclude pregnancy. Kartagener’s syndrome characterized by recurrent respiratory tract infections due to lack of cilia and infertility in men due to defective sperm movement. Turner’s syndrome is characterized by amenorrhea and lack of secondary sexual characteristics. It is excluded in this case because it causes dysmorphic body shape and short stature which are not available in this case.

The correct answer is C

Repeated USMLE Questions Step 1 -151

A 2-year-old boy originally from Egypt is diagnosed with anemia after he took antibiotics for the treatment of otitis media. He has two brothers and one sister. One of his brothers was diagnosed with anemia when he was two years old. His parents were given a list of food and drugs that could be associated with this type of anemia. What is the mode of inheritance of this condition?

A-Autosomal dominant

B-Autosomal recessive

C-X-linked recessive

D-Mitochondrial

E-Multifactorial






Answer

This is a case of glucose-6-phosphate dehydrogenase (G6PD) deficiency which is common in Africa and Mediterranean region. It is x-linked recessive disorder.

The correct answer is C

Repeated USMLE Questions Step 1- 150

You receive a phone call from the nurse of a nursing home telling you that your patient refused to take her medications for the third day. She is 75 years old, competent and has disability of both lower limbs.

What is your best response to the nurse’s concern?

A- Ask the patient for the reason of refusal and don’t force her to take her medications

B- Get help of the staff in the nursing home to force the patient to take her medications as you are responsible for any complications that could happen to her if she doesn’t take her medications.

C- Call her family and address this issue with them to find the best way to solve this problem to avoid any blame if something happens to her

D- Tell the patient that if she doesn’t take her medications then, there is no need to take any future appointments

Answer





Competent patients have the right to refuse to take their medications. Health care provider can only interfere in this situation by asking for the reason of refusal. Other choices are all false. We can't force patients to take their medications as it is considered violation of their right to refuse medication. Calling family is considered HIPAA violation. Heath care providers have obligation to see their patients.

The correct answer is A