1.
Dr Meisenberg
An elderly patient who takes aspirin for chronic arthritis complains about frequent pain in the stomach that can be relieved only by eating. One possible solution to the patient’s problem is to
Correct Answer
E. Switch to a drug that has higher potency on COX-2 relative to COX-1
Explanation
Switching to a drug that has higher potency on COX-2 relative to COX-1 would be a possible solution to the patient's problem. This is because COX-1 is responsible for producing prostaglandins that protect the stomach lining, while COX-2 is responsible for producing prostaglandins that cause inflammation and pain. By using a drug with higher potency on COX-2, it would help to reduce inflammation and pain without affecting the stomach lining as much, thus relieving the frequent stomach pain experienced by the patient.
2.
A routine laboratory test for cardiovascular risk factors in a normal 60-year-old man shows that his levels of both T3 and T4 are only about 20% of normal. TSH is in the normal range, and the thyroid gland is of normal size without palpable masses. There are no clinical signs of abnormal thyroid function. Which of the following proteins is most likely deficient in this patient?
Correct Answer
C. Thyroxin-binding globulin in the blood
Explanation
In this scenario, the patient's levels of both T3 and T4 are significantly lower than normal, indicating a deficiency in the production of thyroid hormones. However, the TSH levels are within the normal range, suggesting that the problem lies outside the thyroid gland itself. The absence of clinical signs of abnormal thyroid function and normal size of the thyroid gland also support this. Thyroxin-binding globulin is a protein that binds to and transports thyroid hormones in the blood. Therefore, a deficiency in thyroxin-binding globulin in the blood is the most likely explanation for the low levels of T3 and T4 in this patient.
3.
A deficiency of aromatase would most likely cause
Correct Answer
A. Virilization of a genetic female
Explanation
Aromatase is an enzyme that converts androgens (male hormones) into estrogens (female hormones). A deficiency of aromatase would result in a decrease in estrogen levels and an increase in androgen levels. In a genetic female, this imbalance would cause virilization, which is the development of male characteristics such as deepening of the voice, increased body hair, and enlargement of the clitoris. Therefore, the correct answer is virilization of a genetic female.
4.
A health food freak whose diet consists mainly of raw cabbage and cassava will most likely develop a deficiency of
Correct Answer
E. Thyroid hormones
Explanation
A health food freak whose diet consists mainly of raw cabbage and cassava will most likely develop a deficiency of thyroid hormones. This is because both raw cabbage and cassava contain goitrogens, which are substances that can interfere with the production of thyroid hormones. Goitrogens can inhibit the uptake of iodine by the thyroid gland, leading to a decreased production of thyroid hormones. Therefore, a diet high in raw cabbage and cassava can result in a deficiency of thyroid hormones.
5.
Dr Martin
Genetic testing of a baby boy reveals a small deletion on chromosome 22. This deletion, called Di George Syndrome, results in defects of migration of neural crest cells. In this syndrome the thymus and inferior parathyroid glands are poorly developed. Which of the pharyngeal pouches was most likely affected?
Correct Answer
C. Third
Explanation
The third pharyngeal pouch is most likely affected in Di George Syndrome. This is because the thymus and inferior parathyroid glands, which are derived from the third pouch, are poorly developed in individuals with this syndrome.
6.
A new born has a unilateral atrophy of the muscles of the cheeks and upper lip including, but not inclusive of zygomaticus major and minor; levator labii superioris and levator anguli oris. The above muscles are derived from which of the listed embryonic resources.
Correct Answer
E. Maxillary prominence
Explanation
The correct answer is Maxillary prominence. The muscles mentioned in the question, such as zygomaticus major and minor, levator labii superioris, and levator anguli oris, are derived from the maxillary prominence during embryonic development. The maxillary prominence is one of the facial prominences that form the different structures of the face.
7.
Dr Kalliecharan
Which of the following statements is characteristic of the pituitary gland?
Correct Answer
D. BasopHils produce FSH and LH
Explanation
Basophils are a type of cells found in the anterior pituitary gland. They are responsible for producing and secreting follicle-stimulating hormone (FSH) and luteinizing hormone (LH). FSH and LH play crucial roles in the regulation of the reproductive system. FSH stimulates the growth and maturation of ovarian follicles in females and sperm production in males. LH triggers ovulation in females and stimulates testosterone production in males. Therefore, the statement that basophils produce FSH and LH is characteristic of the pituitary gland.
8.
Which of the following statements is characteristic of the thyroid gland?
Correct Answer
C. Thyroid follicular cells respond to TSH
Explanation
Thyroid follicular cells respond to TSH. This means that when the thyroid-stimulating hormone (TSH) is released by the pituitary gland, it binds to receptors on the thyroid follicular cells, stimulating them to produce and release thyroid hormones (T4 and T3). This is an important characteristic of the thyroid gland as it plays a crucial role in regulating metabolism and growth in the body.
9.
Which of the hormones is produced primarily in the paraventricular nucleus?
Correct Answer
B. Oxytocin
Explanation
Oxytocin is produced primarily in the paraventricular nucleus. Oxytocin is a hormone that plays a crucial role in social bonding, childbirth, and lactation. It is released during moments of intimacy and is often referred to as the "love hormone." The paraventricular nucleus is a region in the hypothalamus, which is responsible for regulating various physiological processes, including hormone production. Therefore, it is logical that oxytocin, being a hormone, is primarily produced in this specific nucleus.
10.
Characteristics of pinealocytes include which one of the following?
Correct Answer
A. They produce melatonin
Explanation
Pinealocytes are cells found in the pineal gland, and one of their main functions is to produce melatonin. Melatonin is a hormone that helps regulate the sleep-wake cycle and is primarily produced during periods of darkness. Therefore, the statement "They produce melatonin" accurately describes one of the characteristics of pinealocytes.
11.
Dr Dhiman
A 34-year-old man complains of loss of taste and general sensation over anterior two-third of the tongue after having an oral surgery. Which of the following nerves most likely damage during the surgery?
Correct Answer
D. Lingual nerve
Explanation
During the oral surgery, the lingual nerve is most likely damaged. The lingual nerve is responsible for providing taste and general sensation to the anterior two-thirds of the tongue. Therefore, if this nerve is damaged, it can result in loss of taste and general sensation in that area of the tongue. The other nerves listed do not specifically innervate the anterior two-thirds of the tongue, making them less likely to be the cause of the patient's symptoms.
12.
Dr Barremkala
A 22-year-old woman presents to her physician with a neck swelling. She said the swelling started growing suddenly for past 1 week and it started to hurt and she can’t breathe. On Inspection physician identified it as a solitary swelling which moved up on deglutition. On palpation he found the swelling was firm in consistency and it was not attached to the skin. The following statements concerning this swelling would LEAST LIKELY suggest a diagnosis of the thyroid gland swelling?
Correct Answer
C. The swelling is located superficial to the sternothyroid muscle
Explanation
The swelling is located superficial to the sternothyroid muscle suggests a diagnosis of a thyroid gland swelling. The thyroid gland is located deep to the sternothyroid muscle, so a swelling located superficially to this muscle would not be related to the thyroid gland.
13.
Dr Grogan
A 20-year-old patient has muscle weakness and cramps. The evaluation of the patient reveals normoglycemia after random glucose testing and a fasting glucose test. Creatine Kinase is elevated in the patient’s blood. Which glycogen storage disorder best fits with this presentation?
Correct Answer
D. McArdle, Type V
Explanation
The patient's symptoms of muscle weakness and cramps, along with elevated Creatine Kinase levels in the blood, suggest a glycogen storage disorder. McArdle, Type V glycogen storage disorder, also known as muscle phosphorylase deficiency, is characterized by an inability to break down glycogen in muscle cells. This leads to muscle weakness, cramps, and elevated Creatine Kinase levels. The absence of abnormal glucose levels rules out other glycogen storage disorders such as Von Gierke (Type I), Pompe (Type II), Hers (Type VI), and Cori (Type III).
14.
A patient is diagnosed as deficient in the liver cell responsiveness to glucagon activity: An intramuscular glucagon injection resulted in no influence on glucose levels in blood. What enzymatic deficiency in the patient’s liver would be consistent with this ‘glucagon insensitivity’?
Correct Answer
A. Adenylate cyclase deficiency
Explanation
The correct answer is Adenylate cyclase deficiency. Adenylate cyclase is an enzyme involved in the production of cyclic adenosine monophosphate (cAMP), which is a secondary messenger that mediates the effects of glucagon. Glucagon binds to its receptor on liver cells, activating adenylate cyclase and leading to an increase in cAMP levels. This, in turn, triggers a cascade of events that ultimately result in the release of glucose from the liver. If a patient has a deficiency in adenylate cyclase, the production of cAMP would be impaired, leading to a lack of response to glucagon and no influence on glucose levels in the blood.
15.
Dr Selfridge
A 32 year old woman sees you for a complete history and physical examination. She tells you that her father recently died of complications of type II diabetes. On examination her BMI is 32 and her fasting blood glucose is 102 mg/dl. Which of the following is her most important risk factor for developing type II diabetes?
Correct Answer
E. Obesity
Explanation
Obesity is the most important risk factor for developing type II diabetes in this case. The woman's high BMI of 32 indicates that she is significantly overweight, which increases her risk of developing diabetes. Additionally, her fasting blood glucose level of 102 mg/dl is slightly elevated, further indicating a higher risk. Family history, such as her father's death from complications of type II diabetes, also suggests a genetic predisposition to the disease. While factors such as a high fat diet, sedentary lifestyle, high hip to waist ratio, and sugared beverage consumption can contribute to obesity and increase the risk of diabetes, obesity itself is the most significant risk factor in this scenario.
16.
Drs Wright/Thomas
A 42-year-old woman complains to her endocrinologist that she feels jittery and that her heart feels like it is racing. She has also lost some weight, which she is not complaining about. Six months earlier, the woman underwent a thyroidectomy and she has been on thyroxine replacement therapy since that time. Her physician suspects that her thyroxine dose may be too high. Which of the following laboratory findings would support that hypothesis?
Correct Answer
B. Abnormally low thyroid-stimulating hormone levels
Explanation
Explanation (by Dr. Wright): Only choice B is consistent with excess exogenous thyroxine in the plasma. Negative feedback to the hypothalamus and pituitary will result in decreased secretion of TSH, leading to abnormally low plasma levels.
As the woman has no thyroid to sequester iodide, what is absorbed will be excreted, mostly in the urine, so choice A is incorrect. Thyrotropin is another name for TSH, which is abnormally low, not high, so choice C is incorrect. Hyperparathyroidism may or may not be present but it is not relevant to the hypothesis that her thyroxin dose is too high so choice D is not the best answer. Similarly, hyperglycemia is not directly relevant to the hypothesis, so choice E is not the best answer either.
17.
Wright
The nature of feedback loops is a central feature of hypothalamo-pituitary physiology. For which hormone secreted by the pituitary does a signal from the peripheral nervous result in increased secretion?
Correct Answer
D. Prolactin
Explanation
Explanation (by Dr. Wright): Choice D is correct. Suckling at the breast provides a feed-forward sensory signal to the hypothalamus, leading to secretion of additional prolactin to stimulate production of new milk.
All of the other pituitary choices involve more classic endocrine feedback loops, either primarily negative feedback (somatotropin aka Growth Hormone), Thyrotropin aka TSH or Corticotropin aka ACTH); Parathyroid hormone is not a pituitary hormone
18.
A patient with a posterior pituitary disorder secretes too little vasopressin, leading to a decrease in blood pressure. Assuming normal anterior pituitary function, how might the hormones of the adrenal gland respond to this challenge at the level of the kidney?
Correct Answer
D. 4
Explanation
Explanation (Dr. Wright): Blood pressure is low in the first place, for two reasons: Because of excess diuresis, from lack of antidiuretic hormone (ADH, aka vasopressin), and from the lack of the normal tonic constricution of arterioles by vasopressin (aka ADH).
Low blood pressure secondary to hypotension will result in sympathetic nervous stimulation activation and secretion of epinephrine, which will constrict arterioles within the kidney to increase resistance to flow and increase systemic blood pressure. The low blood pressure will also activate the renin-angiotensin system, which will result in the production of angiotensin II, a potent vasoconstrictor in its own right, and the primary signal that stimulates the production of aldosterone. The increased aldosterone will have a strong effect in water retention to maintain plasma volume. Cortisol, as a weak mineralocorticoid, will be secreted as part of the stress response, but in this context its effects will be weak.
The only combination of strong epinephrine vasoconstriction effect, strong aldosterone mineralocorticoid effect, and weak cortisol mineralocorticoid effect is E.
19.
Dr Thomas
A 26-year-old man reports to his physician that he is thirsty all the time and has been drinking a lot of water, which results in his having to urinate so frequently that it is disruptive to his daily activities. In addition, he has to get up frequently during the night to urinate. History reveals that the man sustained a head injury in a motorcycle accident one week earlier. Which of the following drugs is most likely to relieve his symptoms of thirst and diuresis?
Correct Answer
E. Desmopressin
Explanation
The man’s symptoms are consistent with central diabetes insipidus; insufficient vasopressin secretion, possibly secondary to his recent head injury. Desmopressin is a vasopressin analog that would provide replacement therapy for this man. None of the other choices are related to vasopressin or directly to water balance.
20.
A 46-year-old woman is diagnosed with type 2 diabetes mellitus. Her mother also has type 2 diabetes. The woman is found to have a BMI of 32. In addition to receiving nutritional counseling and being referred to an educational support group focused on lifestyle changes to address type 2 diabetes, the woman is prescribed metformin. Which of the following mechanisms of action is likely to be most important in mediating the therapeutic effects of this drug in this patient?
Correct Answer
B. Decreased hepatic gluconeogenesis
Explanation
The liver is the primary target of metformin, where it enhances insulin action to decrease gluconeogenesis and to decrease glycogenolysis; both effects contribute to suppressing circulating glucose.
A) Is an action of thiazolidinediones which are more selective for non-hepatic tissues
C) Is an exenatide effect
D) This is a sulfonylurea action
E) Is an acarbose action
21.
Which of the following is an example of a receptor antagonist action?
Correct Answer
D. Pegvisomant interacting with growth hormone receptors decreases hepatic IGF-1 formation
Explanation
A) Calcium is an allosteric activator of the calcium-sensing receptor; this activation results in decreased PTH secretion
B) Dopamine activation of D2 receptors decreases prolactin secretion; drugs that are dopamine antagonists increase prolactin secretion
C) This is an agonist action
D) Correct: pegvisomant is a growth hormone receptor antagonist. It competes with growth hormone for binding at GH receptors, thus decreasing the ability of GH to stimulate IGF-1 synthesis
E) Somatostatin decreases growth hormone secretion; octreotide is a somatostatin analog which is an agonist at the somatostatin receptor