Q: A patient presents with excessive urination, intense thirst, and high blood glucose. Laboratory tests reveal glucose and ketones in the urine. Which equation best represents the process of gluconeogenesis stimulated by glucagon?

$$ 2 \text{Pyruvate} + 4 \text{ATP} + 2 \text{GTP} + 2 \text{NADH} + 6 \text{H}_2\text{O} \rightarrow \text{Glucose} + 4 \text{ADP} + 2 \text{GDP} + 2 \text{NAD}^+ + 6 \text{P}_i $$

Q: Which equation best represents the negative feedback loop regulating thyroid hormone levels?

$$ \text{TRH} \rightarrow \text{TSH} \rightarrow \text{T}_3/\text{T}_4 $$; when $$ \text{T}_3/\text{T}_4 $$ increases, $$ \text{TRH} $$ and $$ \text{TSH} $$ decrease.

Question 1

Which of the following best describes the mechanism of action for hydrophilic hormones?

Accepted Answer

They bind to membrane receptors, activate second messenger systems such as cAMP, and amplify the signal within the cell.

Question 2

A patient presents with excessive urination, intense thirst, and high blood glucose. Laboratory tests reveal glucose and ketones in the urine. Which equation best represents the process of gluconeogenesis stimulated by glucagon?

Accepted Answer

$$ 2 	ext{Pyruvate} + 4 	ext{ATP} + 2 	ext{GTP} + 2 	ext{NADH} + 6 	ext{H}_2	ext{O} ightarrow 	ext{Glucose} + 4 	ext{ADP} + 2 	ext{GDP} + 2 	ext{NAD}^+ + 6 	ext{P}_i $$

Question 3

Which hormone is synthesized in the hypothalamus but stored and released by the posterior pituitary?

Accepted Answer

Oxytocin

Question 4

A patient with Graves' disease is likely to exhibit which of the following symptoms, and what is the underlying mechanism?

Accepted Answer

Weight loss, heat intolerance, and exophthalmos due to autoimmune stimulation of TSH receptors causing excess thyroid hormone production.

Question 5

Which of the following best explains why steroid hormones have a slower onset but longer duration of action compared to amino acid–based hormones?

Accepted Answer

Steroid hormones must initiate transcription and translation to produce new proteins, a process that takes more time but results in prolonged effects.

Question 6

Which layer of the adrenal cortex is responsible for producing aldosterone, and what is its primary effect?

Accepted Answer

Zona glomerulosa; promotes sodium and water retention, increasing blood pressure.

Question 7

Which equation best represents the negative feedback loop regulating thyroid hormone levels?

Accepted Answer

$$ 	ext{TRH} ightarrow 	ext{TSH} ightarrow 	ext{T}_3/	ext{T}_4 $$; when $$ 	ext{T}_3/	ext{T}_4 $$ increases, $$ 	ext{TRH} $$ and $$ 	ext{TSH} $$ decrease.

Question 8

Which of the following scenarios illustrates a humoral stimulus for hormone secretion?

Accepted Answer

Increased blood glucose stimulates the pancreas to release insulin.

Question 9

A patient with Cushing's syndrome is most likely to have which of the following laboratory findings?

Accepted Answer

High blood glucose, muscle wasting, and central obesity due to excess cortisol.

Question 10

Which of the following best describes the difference between endocrine and exocrine glands?

Accepted Answer

Endocrine glands secrete hormones directly into the bloodstream for intracellular effects, while exocrine glands secrete substances onto epithelial surfaces via ducts for extracellular effects.

Question 11

Which cell type in the pancreas is responsible for lowering blood glucose, and what is the primary mechanism?

Accepted Answer

Beta cells; promote glucose uptake and glycogen synthesis.

Question 12

Which hormone is released in response to decreased blood calcium, and what are its effects?

Accepted Answer

Parathyroid hormone (PTH); increases osteoclast activity, vitamin D activation, and kidney calcium reabsorption.

Question 13

Which of the following hormones is classified as amino acid–based but acts via a hydrophobic mechanism?

Accepted Answer

Thyroid hormone (T3 & T4)

Question 14

A patient with acromegaly has excess growth hormone after adolescence. Which equation best represents the effect of growth hormone on protein synthesis?

Accepted Answer

$$ 	ext{Amino acids} + 	ext{ATP} ightarrow 	ext{Proteins} + 	ext{ADP} $$

Question 15

Which of the following is a primary endocrine organ, and what is its main function?

Accepted Answer

Anterior pituitary; produces hormones that regulate other endocrine glands.

Question 16

Which hormone is released by the adrenal medulla in response to neural stimulation, and what is its effect?

Accepted Answer

Epinephrine; increases heart rate, blood pressure, and bronchodilation.

Question 17

Which of the following best describes the effect of insulin on glucose metabolism after a meal?

Accepted Answer

Insulin promotes glucose uptake by cells and glycogen synthesis, lowering blood glucose.

Question 18

Which of the following is a plausible consequence of long-term untreated type 2 diabetes mellitus?

Accepted Answer

Neuropathy, cardiovascular damage, kidney disease, and poor wound healing due to chronic hyperglycemia.

Question 19

Which equation best represents the effect of aldosterone on sodium and water balance in the kidneys?

Accepted Answer

$$ 	ext{Na}^+_{	ext{urine}} ightarrow 	ext{Na}^+_{	ext{blood}} $$; water follows sodium, increasing blood volume.

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