Nokea
Antidiuretic hormone (ADH) and oxytocin:
- A. are secreted by the neurohypophysis.
- B. are mineralocorticoids.
- C. are secreted by the islets of Langerhans.
- D. stimulate the kidney to excrete Na+ and water.
Correct Answer: A
Rationale: Step-by-step rationale for choice A being correct:
1. ADH and oxytocin are peptide hormones.
2. They are synthesized in the hypothalamus.
3. They are transported and stored in the neurohypophysis.
4. Upon stimulation, they are released from the neurohypophysis.
5. Therefore, both ADH and oxytocin are indeed secreted by the neurohypophysis.
Summary of why other choices are incorrect:
B: ADH and oxytocin are not mineralocorticoids; they regulate water balance and uterine contractions, respectively.
C: Islets of Langerhans secrete insulin and glucagon, not ADH or oxytocin.
D: ADH promotes water reabsorption in the kidneys, opposite to excreting Na+ and water.
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Which of the following is the property in which a hormone CANNOT exhibit its full effect without another hormone?
- A. assertiveness
- B. antagonism
- C. synergism
- D. permissiveness
Correct Answer: D
Rationale: The correct answer is D: permissiveness. Permissiveness is when one hormone enables another hormone to fully exert its effects. The rationale is as follows:
1. Permissiveness allows a hormone to work effectively only when another hormone is present to "permit" its action.
2. Assertiveness (A) and antagonism (B) do not involve the requirement of another hormone for full effect.
3. Synergism (C) involves two hormones working together for a greater effect, but they can still exert some effect individually.
In summary, permissiveness is the only option where a hormone cannot exhibit its full effect without the presence of another hormone.
The inability to produce ADH causes ______.
- A. diabetes mellitus.
- B. uterine contractions.
- C. diabetes insipidus.
- D. decreased urine volume.
Correct Answer: C
Rationale: The correct answer is C: diabetes insipidus. The inability to produce ADH (antidiuretic hormone) results in diabetes insipidus, characterized by excessive thirst and urination. ADH plays a crucial role in regulating water retention by the kidneys. Without ADH, the kidneys are unable to concentrate urine, leading to increased urine output and dehydration.
A: Diabetes mellitus is not caused by the inability to produce ADH. It is a condition characterized by high blood sugar levels due to insufficient insulin production or ineffective use of insulin.
B: Uterine contractions are not related to the production of ADH. Uterine contractions are primarily controlled by hormones such as oxytocin during labor.
D: Decreased urine volume is the opposite of what occurs in diabetes insipidus. In this condition, there is an increase in urine volume due to the inability to concentrate urine.
The only insulin that can be administered intravenously is
- A. Lente
- B. Semi-Lente
- C. regular
- D. NPH
Correct Answer: C
Rationale: Only regular insulin is approved for intravenous administration due to its rapid onset and shorter duration of action.
Peptide hormones _______________.
- A. are hydrophilic
- B. cannot enter the target cell
- C. bind to a receptor on the cell surface
- D. all of these
Correct Answer: D
Rationale: The correct answer is D because peptide hormones are hydrophilic molecules that cannot pass through the cell membrane, so they bind to receptors on the cell surface to initiate signaling pathways within the cell. Therefore, they are unable to enter the target cell like lipid-soluble hormones do. By binding to specific receptors on the cell surface, peptide hormones trigger a series of events that ultimately lead to a cellular response. Therefore, all of the given statements are true, making D the correct choice.
Ketoacidosis is most related to:
- A. adrenocortical insufficiency.
- B. Cushing syndrome.
- C. excess fatty acid catabolism.
- D. hyperglycemia.
Correct Answer: C
Rationale: Ketoacidosis is most related to excess fatty acid catabolism. During this process, the body breaks down fatty acids into ketones, leading to an accumulation of ketones in the blood and causing metabolic acidosis. Adrenocortical insufficiency (A) is related to cortisol deficiency, not ketoacidosis. Cushing syndrome (B) is associated with excess cortisol production, not ketoacidosis. Hyperglycemia (D) is high blood sugar levels and is not directly related to the mechanism of ketoacidosis.