Q: Which of the following equations correctly represents the negative feedback regulation of blood calcium by parathyroid hormone (PTH)?

$$\text{Low } [Ca$$^{2+}$$] \rightarrow \text{PTH release} \rightarrow \text{Increase } [Ca$$^{2+}$$] \rightarrow \text{Inhibit PTH}$$

Question 1

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

Accepted Answer

Endocrine glands secrete hormones directly into the bloodstream, while exocrine glands release their secretions through ducts to external or internal surfaces.

Question 2

A patient presents with symptoms of muscle weakness, kidney stones, and high blood calcium levels. Which endocrine disorder is most likely responsible?

Accepted Answer

Hyperparathyroidism

Question 3

Which hormone mechanism involves the activation of a secondary messenger such as cAMP, leading to phosphorylation of proteins?

Accepted Answer

Water-soluble hormone mechanism

Question 4

Which of the following hormones is derived from cholesterol and is lipid-soluble?

Accepted Answer

Cortisol

Question 5

A patient with Graves' disease is likely to experience which of the following symptoms?

Accepted Answer

Bulging eyes (exophthalmos) and increased metabolism

Question 6

Which hormone is released in response to low blood calcium levels and promotes the release of calcium from bones?

Accepted Answer

Parathyroid hormone (PTH)

Question 7

Which of the following is an example of antagonism in hormone interactions?

Accepted Answer

Insulin lowers blood glucose while glucagon raises it

Question 8

Which hormone is responsible for stimulating uterine contractions during labor and milk ejection after delivery?

Accepted Answer

Oxytocin

Question 9

A patient with Cushing's disease is likely to show which of the following laboratory findings?

Accepted Answer

Elevated ACTH and increased blood glucose

Question 10

Which of the following best explains the permissiveness effect in hormone interactions?

Accepted Answer

One hormone requires the presence of another hormone to exert its full effect

Question 11

Which hormone is secreted by the adrenal medulla and is involved in the 'fight or flight' response?

Accepted Answer

Epinephrine

Question 12

Which of the following is a correct sequence for the action of a water-soluble hormone?

Accepted Answer

Hormone binds to membrane receptor $$\rightarrow$$ activates G protein $$\rightarrow$$ activates adenylate cyclase $$\rightarrow$$ increases cAMP $$\rightarrow$$ activates protein kinase

Question 13

Which hormone is released by the pancreas in response to high blood glucose and promotes glucose uptake by cells?

Accepted Answer

Insulin

Question 14

Which of the following is a function of aldosterone?

Accepted Answer

Regulates sodium and potassium ion concentrations in body fluids

Question 15

A patient with diabetes insipidus is most likely to have a deficiency in which hormone?

Accepted Answer

Antidiuretic hormone (ADH)

Question 16

Which hormone is produced by the pineal gland and regulates circadian rhythms?

Accepted Answer

Melatonin

Question 17

Which of the following best describes the action of steroid hormones?

Accepted Answer

They bind to intracellular receptors and alter gene transcription

Question 18

Which hormone is responsible for stimulating the production of red blood cells in the bone marrow?

Accepted Answer

Erythropoietin

Question 19

Which of the following equations correctly represents the negative feedback regulation of blood calcium by parathyroid hormone (PTH)?

Accepted Answer

$$	ext{Low } [Ca$$^{2+}$$] ightarrow 	ext{PTH release} ightarrow 	ext{Increase } [Ca$$^{2+}$$] ightarrow 	ext{Inhibit PTH}$$

Question 20

A patient is experiencing dehydration, low blood pressure, and low sodium levels. Which hormone is most likely deficient?

Accepted Answer

Aldosterone

Endocrine System: Hormones, Mechanisms, and Functional Classification

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