Exam 2: Physiology of Cells and Molecules

A 45-year-old woman is concerned by a history of episodes of confusion and fainting over the past year that occur either on first arising in the morning or after exercising. The episodes are preceded or accompanied by shaking, sweating, and palpitations. The woman's husband has noticed that eating can prevent the onset of symptoms. Which of the following is the most likely cause of this patient's symptoms?

Which one of the following statements is correct regarding salivary secretion?

A 32-year-old female undergoes an appendectomy without complications, but has markedly reduced bowel sounds and an absence of flatus or defecation during the immediate postoperative period. Which of the following mechanisms best explains this decrease in bowel sounds?

A 45-year-old woman arrives at the clinic and exhibits athetoid movements. She probably has a:

A middle-aged woman has had asthma since childhood and has been a heavy smoker since her early teens. During the past few years, she has experienced progressive dyspnea (breathing difficulty) and somnolence (sleepiness). Physical examination reveals a cachectic (general ill health and malnutrition) female with shortness of breath, prolonged expirations, and frequent coughing. Laboratory data are as follows: arterial pH 7.35; arterial HCO₃^- 32 mEq/L; arterial PCO₂ 60 mmHg; and arterial PO₂, 60 mmHg. Which of the following is a likely diagnosis?

Consider a patient with pH = 7.33; [HCO₃^-] = 36 mEq/L; PCO₂ = 70 mmHg. What is the acid-base status of the patient?

A 58-year-old woman has left hemiparesis and right ptosis (droopy eyelids). She cannot adduct, elevate, or depress her right eye. The most likely cause of these findings is a lesion in which of the following sites?

A medical student complains of severe vomiting and diarrhea for 2 days since eating at the Roadkill Café. His blood pressure is 120/70 mmHg supine and 90/50 mmHg standing. His skin and mucous membranes are dry. Which of the following laboratory finding would you expect to find?

A 56-year-old obese woman suffering from heartburn and regurgitation of acid saliva after large meals is treated with cimetidine. During cimetidine treatment, her serum creatinine concentration increases significantly. The increase in serum creatinine with cimetidine treatment is most likely due to:

The primary source of estriol (E₃) during pregnancy is the:

A 46-year-old man complains of progressive muscle weakness. Laboratory studies show a serum pH of 7.6, HCO₃^- of 32 mEq/L, and an elevated plasma aldosterone concentration. The most likely cause of muscle weakness in this patient is:

A middle-aged man is evaluated for polydipsia and polyuria. His 24-hour urine volume is 7.0 L with a low osmolality, and is negative for red blood cells, leukocytes, protein, and glucose. His blood pressure and heart rate are both normal. Which of the following is a likely cause of polyuria in this patient?

A newborn presents with somewhat ambiguous external genitalia. The genitalia appear as an enlarged clitoris and a scrotum-like structure that appears to result from labial fusion. An ultrasound reveals normal ovarian development. The karyotype is 46 XX. The findings are most likely due to a deficiency in which one of the following enzymes?

Your patient has been diagnosed with malignant hyperthermia after a surgical procedure. The most common cause of malignant hyperthermia in humans is an Abnormal response to general anesthetics involving the:

A 16-year-old boy has become totally deaf in his left ear after a motor vehicle accident even though hearing in his right ear is normal. A lesion at which of the following sites is the most likely cause of this finding?

A 30-year-old female patient with hypercapnia that is not the result of compensation for an acid-base disturbance is seen in the clinic. Thus, this patient is suffering from:

A 30-year-old man complains of progressive muscle weakness and double vision (diplopia) and some difficulty in swallowing solid foods. Neurologic studies show a neuromuscular conduction defect, and diagnostic studies with an intravenous injection of edrophonium are found to rapidly increase his muscle strength. When the patient is treated with neostigmine, his status improves. The most probable target molecule in this treatment is:

In a patient recovering from cholera, pH = 7.35; [HCO₃^-] = 16 mEq/L; PCO₂ = 30 mmHg. What is the acid-base status of the patient?

A 60-year-old man develops an acute onset of confusion, ataxia, nystagmus, and hypothermia shortly after the administration of an intravenous solution containing 5% glucose and normal saline. The pathogenesis of this patient's neurologic disorder is most closely related to which of the following conditions?

A 70-year-old man complains of weakness in his right leg. Physical examination is notable for hyperactive muscle stretch reflexes, a positive Babinski sign, and diffuse areas of weakness in his right leg. Although he can accurately distinguish sharp and dull pain in the right leg he is unable to distinguish these types of pain in his left leg. The most likely cause of these findings is a lesion in the: