Question 1

Which of the following best describes the difference between acute and chronic responses in homeostasis, as illustrated in Cannon’s Postulates?

Accepted Answer

Acute responses involve rapid changes such as neurotransmitter release, while chronic responses involve slower, ongoing regulation such as hormone secretion.

Question 2

According to Cannon’s Postulates, which mechanism allows one chemical signal to have different effects in different tissues?

Accepted Answer

Different receptor types for the same chemical signal

Question 3

Which of the following is a key feature of hormones compared to neurotransmitters?

Accepted Answer

Hormones are secreted into the blood and can act on distant targets.

Question 4

A patient has a mutation that prevents the synthesis of peptide hormones. Which physiological process would be most directly affected?

Accepted Answer

Regulation of blood glucose by insulin

Question 5

Which equation best represents the lock-and-key model of hormone-receptor interaction?

Accepted Answer

$$H + R \rightarrow HR$$

Question 6

Which of the following is NOT a mechanism for stimulating hormone release from endocrine glands?

Accepted Answer

Passive diffusion of hormones across cell membranes

Question 7

Steroid hormones differ from peptide hormones in that steroid hormones:

Accepted Answer

Are synthesized from cholesterol and can diffuse through cell membranes

Question 8

Which of the following best explains why steroid hormones have a longer half-life than peptide hormones?

Accepted Answer

Steroid hormones are bound to carrier proteins in the blood, protecting them from rapid degradation.

Question 9

A researcher is studying a hormone that is derived from tyrosine and acts as a neurotransmitter in the brain. Which hormone is most likely being studied?

Accepted Answer

Dopamine

Question 10

Which of the following best describes the role of the hypothalamic-pituitary axis in endocrine regulation?

Accepted Answer

It coordinates the release of trophic hormones that regulate other endocrine glands.

Question 11

Which of the following is an example of antagonistic control in homeostasis?

Accepted Answer

Insulin lowers blood glucose while glucagon raises it.

Question 12

Which hormone is secreted by the posterior pituitary and is involved in water retention?

Accepted Answer

Antidiuretic hormone (ADH)

Question 13

Which of the following best describes the function of the portal system in the hypothalamic-pituitary axis?

Accepted Answer

It ensures that releasing hormones from the hypothalamus reach the anterior pituitary at high concentrations.

Question 14

A patient presents with symptoms of chronic stress. Which hormone is most likely elevated in their blood?

Accepted Answer

Cortisol

Question 15

Which of the following is a direct effect of peptide hormone binding to its receptor?

Accepted Answer

Activation of intracellular second messenger pathways

Question 16

Which equation best represents the negative feedback mechanism in endocrine regulation?

Accepted Answer

$$	ext{Stimulus} ightarrow 	ext{Hormone Release} ightarrow 	ext{Response} ightarrow 	ext{Decrease in Stimulus}$$

Question 17

Which of the following hormones is derived from tryptophan?

Accepted Answer

Melatonin

Question 18

Which of the following best explains why peptide hormones cannot cross the cell membrane?

Accepted Answer

They are polar and hydrophilic, requiring membrane receptors.

Question 19

A patient has a deficiency in the hormone erythropoietin (EPO). Which physiological process will be most affected?

Accepted Answer

Production of red blood cells

Question 20

Which of the following is a correct sequence for the synthesis and release of peptide hormones?

Accepted Answer

$$	ext{Preprohormone} ightarrow 	ext{Prohormone} ightarrow 	ext{Active Hormone}$$

Homeostasis and Endocrine System: Hormones and Regulation

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