HSC 4558 Exam 4 V3 | HSC 4558 Pathophysiology II | Actual Q&A with
Rationale (HSC4558 Exam 4) | University of Central Florida
1. A 24-year-old patient presents with polyuria, polydipsia, and weight loss. Laboratory
results reveal an absolute deficiency of insulin production. Which of the following best
describes the pathogenesis of this condition?
A. Peripheral insulin resistance and beta cell exhaustion
B. Excessive glucagon secretion from alpha cells
C. Autoimmune destruction of pancreatic beta cells
D. Chronic inflammation of the exocrine pancreas
Answer: C
Explanation: Type 1 Diabetes Mellitus is characterized by the autoimmune-mediated
destruction of the insulin-producing beta cells in the Islets of Langerhans. This leads to an
absolute insulin deficiency, requiring the patient to depend on exogenous insulin for
survival. The lack of insulin prevents glucose uptake into cells, resulting in the classic triad
of polyuria, polydipsia, and polyphagia.
2. Which clinical manifestation is uniquely associated with Graves’ disease compared to other
forms of hyperthyroidism?
A. Weight loss despite increased appetite
B. Tachycardia
C. Heat intolerance
D. Exophthalmos
Answer: D
Explanation: Graves’ disease is an autoimmune disorder where thyroid-stimulating
immunoglobulins (TSI) mimic TSH and overstimulate the thyroid gland. Exophthalmos, or
bulging of the eyes, is caused by fibroblasts in the orbital tissue reacting to the autoimmune
process. While tachycardia and heat intolerance are common to all hyperthyroid states,
exophthalmos and pretibial myxedema are specific to Graves’ disease.
3. A patient with a history of small cell lung cancer presents with weight gain, a ‘buffalo
hump,’ and purple striae on the abdomen. What is the most likely pathophysiological
classification of this patient’s condition?
A. Primary Adrenal Insufficiency
B. Pituitary-dependent Cushing’s Disease
,C. Conn’s Syndrome
D. Ectopic Cushing’s Syndrome
Answer: D
Explanation: Ectopic Cushing’s syndrome occurs when non-pituitary tumors, such as small
cell lung cancer, secrete adrenocorticotropic hormone (ACTH). This leads to bilateral
adrenal hyperplasia and excessive cortisol production, manifesting as the classic symptoms
of hypercortisolism. This differs from Cushing’s Disease, which specifically refers to a
pituitary adenoma secreting ACTH.
4. Hashimoto’s thyroiditis is characterized by which of the following laboratory profiles?
A. High T3, High T4, Low TSH
B. Normal T4, Normal TSH
C. Low T4, Low TSH
D. Low T4, High TSH
Answer: D
Explanation: Hashimoto’s thyroiditis is the most common cause of hypothyroidism in
iodine-sufficient areas and involves the autoimmune destruction of the thyroid gland. As
the thyroid gland fails to produce adequate T4, the pituitary gland increases TSH
production via a negative feedback loop to stimulate the thyroid. This results in the
characteristic high TSH and low free T4 levels observed in primary hypothyroidism.
5. Which condition is defined by a primary deficiency in both cortisol and aldosterone due to
adrenal cortex destruction?
A. Secondary Adrenal Insufficiency
B. Cushing’s Syndrome
C. Addison’s Disease
D. Diabetes Insipidus
Answer: C
Explanation: Addison’s disease, or primary adrenal insufficiency, involves the destruction
of all layers of the adrenal cortex, often due to an autoimmune process. This leads to a
deficiency in glucocorticoids (cortisol), mineralocorticoids (aldosterone), and androgens.
The loss of aldosterone leads to hyponatremia, hyperkalemia, and severe dehydration,
which can result in an adrenal crisis.
6. A patient exhibits high volumes of dilute urine and profound thirst following a head injury
that damaged the posterior pituitary. Which hormone is deficient?
A. Oxytocin
, B. Aldosterone
C. Antidiuretic Hormone (ADH)
D. Renin
Answer: C
Explanation: Neurogenic diabetes insipidus is caused by a deficiency in the synthesis or
release of Antidiuretic Hormone (ADH) from the posterior pituitary. Without ADH, the
distal tubules and collecting ducts in the kidney are unable to reabsorb water, leading to
the excretion of large volumes of dilute urine. This condition results in significant serum
hyperosmolality and compensatory polydipsia.
7. In the Syndrome of Inappropriate Antidiuretic Hormone (SIADH), which electrolyte
imbalance is most concerning?
A. Hyperkalemia
B. Hyponatremia
C. Hypocalcemia
D. Hypernatremia
Answer: B
Explanation: SIADH involves the excessive release of ADH, which causes the kidneys to
retain water despite normal or low serum osmolality. This excessive water retention leads
to dilutional hyponatremia, as the sodium in the blood becomes overly diluted by the
increased plasma volume. Severe hyponatremia can lead to cerebral edema, seizures, and
neurological deterioration if not managed carefully.
8. Hyperparathyroidism typically leads to which of the following skeletal complications?
A. Increased bone density
B. Osteopetrosis
C. Pathologic fractures
D. Excessive collagen synthesis
Answer: C
Explanation: Hyperparathyroidism results in excessive secretion of parathyroid hormone
(PTH), which stimulates osteoclast activity to release calcium from the bones into the
blood. This chronic resorption of bone minerals weakens the skeletal structure,
significantly increasing the risk of osteoporosis and pathologic fractures. Patients often
present with ‘bones, stones, abdominal groans, and psychic moans’ due to hypercalcemia.
Rationale (HSC4558 Exam 4) | University of Central Florida
1. A 24-year-old patient presents with polyuria, polydipsia, and weight loss. Laboratory
results reveal an absolute deficiency of insulin production. Which of the following best
describes the pathogenesis of this condition?
A. Peripheral insulin resistance and beta cell exhaustion
B. Excessive glucagon secretion from alpha cells
C. Autoimmune destruction of pancreatic beta cells
D. Chronic inflammation of the exocrine pancreas
Answer: C
Explanation: Type 1 Diabetes Mellitus is characterized by the autoimmune-mediated
destruction of the insulin-producing beta cells in the Islets of Langerhans. This leads to an
absolute insulin deficiency, requiring the patient to depend on exogenous insulin for
survival. The lack of insulin prevents glucose uptake into cells, resulting in the classic triad
of polyuria, polydipsia, and polyphagia.
2. Which clinical manifestation is uniquely associated with Graves’ disease compared to other
forms of hyperthyroidism?
A. Weight loss despite increased appetite
B. Tachycardia
C. Heat intolerance
D. Exophthalmos
Answer: D
Explanation: Graves’ disease is an autoimmune disorder where thyroid-stimulating
immunoglobulins (TSI) mimic TSH and overstimulate the thyroid gland. Exophthalmos, or
bulging of the eyes, is caused by fibroblasts in the orbital tissue reacting to the autoimmune
process. While tachycardia and heat intolerance are common to all hyperthyroid states,
exophthalmos and pretibial myxedema are specific to Graves’ disease.
3. A patient with a history of small cell lung cancer presents with weight gain, a ‘buffalo
hump,’ and purple striae on the abdomen. What is the most likely pathophysiological
classification of this patient’s condition?
A. Primary Adrenal Insufficiency
B. Pituitary-dependent Cushing’s Disease
,C. Conn’s Syndrome
D. Ectopic Cushing’s Syndrome
Answer: D
Explanation: Ectopic Cushing’s syndrome occurs when non-pituitary tumors, such as small
cell lung cancer, secrete adrenocorticotropic hormone (ACTH). This leads to bilateral
adrenal hyperplasia and excessive cortisol production, manifesting as the classic symptoms
of hypercortisolism. This differs from Cushing’s Disease, which specifically refers to a
pituitary adenoma secreting ACTH.
4. Hashimoto’s thyroiditis is characterized by which of the following laboratory profiles?
A. High T3, High T4, Low TSH
B. Normal T4, Normal TSH
C. Low T4, Low TSH
D. Low T4, High TSH
Answer: D
Explanation: Hashimoto’s thyroiditis is the most common cause of hypothyroidism in
iodine-sufficient areas and involves the autoimmune destruction of the thyroid gland. As
the thyroid gland fails to produce adequate T4, the pituitary gland increases TSH
production via a negative feedback loop to stimulate the thyroid. This results in the
characteristic high TSH and low free T4 levels observed in primary hypothyroidism.
5. Which condition is defined by a primary deficiency in both cortisol and aldosterone due to
adrenal cortex destruction?
A. Secondary Adrenal Insufficiency
B. Cushing’s Syndrome
C. Addison’s Disease
D. Diabetes Insipidus
Answer: C
Explanation: Addison’s disease, or primary adrenal insufficiency, involves the destruction
of all layers of the adrenal cortex, often due to an autoimmune process. This leads to a
deficiency in glucocorticoids (cortisol), mineralocorticoids (aldosterone), and androgens.
The loss of aldosterone leads to hyponatremia, hyperkalemia, and severe dehydration,
which can result in an adrenal crisis.
6. A patient exhibits high volumes of dilute urine and profound thirst following a head injury
that damaged the posterior pituitary. Which hormone is deficient?
A. Oxytocin
, B. Aldosterone
C. Antidiuretic Hormone (ADH)
D. Renin
Answer: C
Explanation: Neurogenic diabetes insipidus is caused by a deficiency in the synthesis or
release of Antidiuretic Hormone (ADH) from the posterior pituitary. Without ADH, the
distal tubules and collecting ducts in the kidney are unable to reabsorb water, leading to
the excretion of large volumes of dilute urine. This condition results in significant serum
hyperosmolality and compensatory polydipsia.
7. In the Syndrome of Inappropriate Antidiuretic Hormone (SIADH), which electrolyte
imbalance is most concerning?
A. Hyperkalemia
B. Hyponatremia
C. Hypocalcemia
D. Hypernatremia
Answer: B
Explanation: SIADH involves the excessive release of ADH, which causes the kidneys to
retain water despite normal or low serum osmolality. This excessive water retention leads
to dilutional hyponatremia, as the sodium in the blood becomes overly diluted by the
increased plasma volume. Severe hyponatremia can lead to cerebral edema, seizures, and
neurological deterioration if not managed carefully.
8. Hyperparathyroidism typically leads to which of the following skeletal complications?
A. Increased bone density
B. Osteopetrosis
C. Pathologic fractures
D. Excessive collagen synthesis
Answer: C
Explanation: Hyperparathyroidism results in excessive secretion of parathyroid hormone
(PTH), which stimulates osteoclast activity to release calcium from the bones into the
blood. This chronic resorption of bone minerals weakens the skeletal structure,
significantly increasing the risk of osteoporosis and pathologic fractures. Patients often
present with ‘bones, stones, abdominal groans, and psychic moans’ due to hypercalcemia.
