NUR 631/NUR631 Exam 4 V1 | Advanced
Physiology and Pathophysiology Q&A with
Rationale | Grand Canyon University
1. A patient presents with a serum sodium level of 120 mEq/L and high urine osmolality.
Which condition is most likely responsible for these findings?
A. Diabetes Insipidus
B. Cushing Syndrome
C. SIADH
D. Addison Disease
Correct Answer: C
Expert Explanation: SIADH involves the excessive release of antidiuretic hormone
regardless of serum osmolality. This causes the kidneys to reabsorb water excessively,
leading to dilutional hyponatremia. The condition is often associated with certain cancers
or central nervous system disorders.
2. Which pathophysiological mechanism is central to the development of Type 1 Diabetes
Mellitus?
A. Insulin resistance in peripheral tissues
B. Hypersecretion of glucagon from alpha cells
C. Decreased glucose uptake by the liver
,D. Autoimmune destruction of pancreatic beta cells
Correct Answer: D
Expert Explanation: Type 1 Diabetes Mellitus is characterized by an absolute deficiency of
insulin. This occurs when the body’s immune system mistakenly attacks and destroys the
insulin-producing beta cells in the islets of Langerhans. Without insulin, glucose cannot
enter cells for energy, leading to hyperglycemia.
3. A patient with Graves disease exhibits bulging eyes, also known as exophthalmos. What is
the underlying cause of this clinical manifestation?
A. Accumulation of orbital connective tissue and edema
B. Increased intraocular pressure
C. Weakness of the extraocular muscles
D. Excessive lacrimation from the tear ducts
Correct Answer: A
Expert Explanation: Graves disease is an autoimmune form of hyperthyroidism that
involves thyroid-stimulating immunoglobulins. These antibodies also react with tissues
behind the eyes, leading to inflammation and accumulation of fat and connective tissue.
The resulting swelling pushes the eyeballs forward, creating the characteristic bulging
appearance.
, 4. In the context of Chronic Kidney Disease (CKD), why do patients often develop secondary
hyperparathyroidism?
A. Reduced activation of Vitamin D and hyperphosphatemia
B. Excessive calcium intake in the diet
C. Direct stimulation of the parathyroid gland by urea
D. Primary tumor formation in the parathyroid glands
Correct Answer: A
Expert Explanation: As kidney function declines, the production of active Vitamin D
decreases, which impairs calcium absorption. Additionally, the kidneys fail to excrete
phosphate, leading to high serum phosphate levels that further lower serum calcium. The
parathyroid glands respond to low calcium and high phosphate by secreting excessive PTH
to mobilize calcium from bones.
5. Which of the following describes the ‘skip lesions’ characteristic of Crohn’s disease?
A. Continuous inflammation of the mucosal layer
B. Inflammation limited only to the sigmoid colon
C. Ulcerations that only affect the rectum
D. Discontinuous areas of inflammation throughout the GI tract
Correct Answer: D
Physiology and Pathophysiology Q&A with
Rationale | Grand Canyon University
1. A patient presents with a serum sodium level of 120 mEq/L and high urine osmolality.
Which condition is most likely responsible for these findings?
A. Diabetes Insipidus
B. Cushing Syndrome
C. SIADH
D. Addison Disease
Correct Answer: C
Expert Explanation: SIADH involves the excessive release of antidiuretic hormone
regardless of serum osmolality. This causes the kidneys to reabsorb water excessively,
leading to dilutional hyponatremia. The condition is often associated with certain cancers
or central nervous system disorders.
2. Which pathophysiological mechanism is central to the development of Type 1 Diabetes
Mellitus?
A. Insulin resistance in peripheral tissues
B. Hypersecretion of glucagon from alpha cells
C. Decreased glucose uptake by the liver
,D. Autoimmune destruction of pancreatic beta cells
Correct Answer: D
Expert Explanation: Type 1 Diabetes Mellitus is characterized by an absolute deficiency of
insulin. This occurs when the body’s immune system mistakenly attacks and destroys the
insulin-producing beta cells in the islets of Langerhans. Without insulin, glucose cannot
enter cells for energy, leading to hyperglycemia.
3. A patient with Graves disease exhibits bulging eyes, also known as exophthalmos. What is
the underlying cause of this clinical manifestation?
A. Accumulation of orbital connective tissue and edema
B. Increased intraocular pressure
C. Weakness of the extraocular muscles
D. Excessive lacrimation from the tear ducts
Correct Answer: A
Expert Explanation: Graves disease is an autoimmune form of hyperthyroidism that
involves thyroid-stimulating immunoglobulins. These antibodies also react with tissues
behind the eyes, leading to inflammation and accumulation of fat and connective tissue.
The resulting swelling pushes the eyeballs forward, creating the characteristic bulging
appearance.
, 4. In the context of Chronic Kidney Disease (CKD), why do patients often develop secondary
hyperparathyroidism?
A. Reduced activation of Vitamin D and hyperphosphatemia
B. Excessive calcium intake in the diet
C. Direct stimulation of the parathyroid gland by urea
D. Primary tumor formation in the parathyroid glands
Correct Answer: A
Expert Explanation: As kidney function declines, the production of active Vitamin D
decreases, which impairs calcium absorption. Additionally, the kidneys fail to excrete
phosphate, leading to high serum phosphate levels that further lower serum calcium. The
parathyroid glands respond to low calcium and high phosphate by secreting excessive PTH
to mobilize calcium from bones.
5. Which of the following describes the ‘skip lesions’ characteristic of Crohn’s disease?
A. Continuous inflammation of the mucosal layer
B. Inflammation limited only to the sigmoid colon
C. Ulcerations that only affect the rectum
D. Discontinuous areas of inflammation throughout the GI tract
Correct Answer: D
