Endocrine System Questions and Answers PDF

Endocrine System Questions and Answers PDF Related

Review Endocrine System Questions and Answers PDF related questions and content

The production and release of hormones caused by a chemical such as calcium is a _____ mechanism.

  • A. humoral
  • B. neural
  • C. sensory
  • D. hormonal
Correct Answer: A

Rationale: The correct answer is A: humoral. Humoral regulation refers to the control of physiological processes by substances in the blood, such as hormones. In this case, the production and release of hormones in response to a chemical like calcium is an example of humoral mechanism. This choice is correct because it specifically involves the blood-borne substances affecting hormone production.

Choices B, C, and D are incorrect because neural regulation (B) involves the nervous system controlling physiological processes, sensory regulation (C) refers to sensory input influencing responses, and hormonal regulation (D) involves feedback loops within the endocrine system, not directly related to blood-borne substances like calcium.

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The cluster of cells in the pancreas that secrete hormones are:

  • A. Nodules
  • B. Islets of Langerhans
  • C. Pancreatic medulla
  • D. Pancreatic cortex
Correct Answer: B

Rationale: The correct answer is B: Islets of Langerhans. These clusters of cells in the pancreas are responsible for secreting hormones such as insulin and glucagon. Islets of Langerhans contain different types of cells that regulate blood sugar levels. Nodules (A), pancreatic medulla (C), and pancreatic cortex (D) are not associated with hormone secretion in the pancreas. Nodules are more general and not specific to the pancreas, while pancreatic medulla and cortex do not house the endocrine cells responsible for hormone secretion.

Which of the following stimulates the release of parathyroid hormone?

  • A. TSH from the posterior pituitary gland
  • B. high levels of calcium in the blood
  • C. calcitonin from the anterior pituitary gland
  • D. low levels of calcium in the blood
Correct Answer: D

Rationale: The correct answer is D: low levels of calcium in the blood. Parathyroid hormone is released in response to low blood calcium levels to help increase calcium levels by promoting its release from bones and enhancing its absorption in the intestines. This response helps maintain calcium homeostasis. TSH from the posterior pituitary gland (choice A) is not related to parathyroid hormone release. High levels of calcium in the blood (choice B) would not stimulate parathyroid hormone release as it is released in response to low calcium levels. Calcitonin from the anterior pituitary gland (choice C) actually works in opposition to parathyroid hormone by promoting calcium deposition in bones and decreasing blood calcium levels.

Which conditions would give the results shown in diagrams X and Y?

  • A. carbon dioxide, 25°C, oxygen, 25°C
  • B. carbon dioxide, 2°C, oxygen, 2°C
  • C. oxygen, 25°C, carbon dioxide, 25°C
  • D. oxygen, 2°C, carbon dioxide, 2°C
Correct Answer: C

Rationale: The correct answer is C because diagram X shows an increase in oxygen concentration over time, which indicates photosynthesis occurring. In photosynthesis, plants take in carbon dioxide and release oxygen. Therefore, the conditions of oxygen at 25°C and carbon dioxide at 25°C would support this process. Choices A, B, and D have incorrect combinations of temperature and gases that would not result in the observed increase in oxygen concentration in diagram X.

Which is NOT produced by the citric acid cycle?

  • A. NAD+
  • B. CO2
  • C. GTP
  • D. FADH2
Correct Answer: A

Rationale: Step 1: NAD+ is a reactant in the citric acid cycle, not a product.
Step 2: NAD+ is reduced to NADH during the cycle.
Step 3: NAD+ is not directly produced as a final product in the cycle.
Step 4: Therefore, A: NAD+ is NOT produced by the citric acid cycle.
Summary: B: CO2 and D: FADH2 are produced in the cycle, while C: GTP is generated through substrate-level phosphorylation.

The endocrine gland responsible for the body's circadian rhythm is the:

  • A. Thymus gland.
  • B. Pineal gland.
  • C. Parathyroid gland.
  • D. Pituitary gland.
Correct Answer: B

Rationale: The correct answer is B: Pineal gland. The pineal gland produces melatonin, a hormone that regulates the body's circadian rhythm, including sleep-wake cycles. This gland is sensitive to light and darkness, influencing the body's internal clock.
A: Thymus gland is responsible for immune function, not circadian rhythm.
C: Parathyroid gland regulates calcium levels in the body, not circadian rhythm.
D: Pituitary gland controls various other hormones but not specifically circadian rhythm.

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