Nokea
Which nerve is NOT involved in the efferent (motor) swallow reflex?
- A. trigeminal
- B. vagus
- C. facial
- D. hypoglossal
Correct Answer: B
Rationale: The correct answer is B: vagus. The efferent (motor) swallow reflex involves motor nerves that control swallowing muscles. The vagus nerve (cranial nerve X) is primarily responsible for the afferent (sensory) component of the swallow reflex, while the efferent component is carried out by other cranial nerves such as the glossopharyngeal (IX), facial (VII), and hypoglossal (XII) nerves. Therefore, the vagus nerve is not directly involved in the efferent motor response during swallowing. Trigeminal (V), facial (VII), and hypoglossal (XII) nerves play essential roles in the motor aspects of swallowing, making them incorrect choices.
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The 'hormone response element' is located on the cell __________.
- A. membrane
- B. DNA
- C. RNA
- D. enzymes
Correct Answer: B
Rationale: The correct answer is B: DNA. Hormone response elements are specific DNA sequences where hormone receptors bind to regulate gene expression. This binding initiates the transcription of target genes. Choices A, C, and D are incorrect because hormone response elements are not located on the cell membrane, RNA, or enzymes. The key is understanding that hormone receptors act on DNA to regulate gene expression, making choice B the most appropriate answer.
The secretions from which of these glands differs between males and females?
- A. Adrenal.
- B. Parathyroid.
- C. Gonadal.
- D. Pancreas.
Correct Answer: C
Rationale: The correct answer is C: Gonadal. The secretions from gonads (testes in males, ovaries in females) differ between males and females due to the production of sex hormones (testosterone in males, estrogen and progesterone in females). Adrenal glands (A) secrete similar hormones in both genders. Parathyroid (B) and Pancreas (D) do not secrete hormones that differ based on gender.
The adenohypophysis:
- A. secretes ADH and oxytocin.
- B. refers to the anterior pituitary gland.
- C. secretes releasing hormones.
- D. secretes glucocorticoids, mineralocorticoids, and androgens.
Correct Answer: B
Rationale: The correct answer is B because the adenohypophysis refers specifically to the anterior pituitary gland, which secretes various hormones like growth hormone, prolactin, and thyroid-stimulating hormone. Choice A is incorrect because ADH and oxytocin are actually secreted by the neurohypophysis (posterior pituitary). Choice C is incorrect because releasing hormones are secreted by the hypothalamus, not the adenohypophysis. Choice D is incorrect because glucocorticoids, mineralocorticoids, and androgens are actually secreted by the adrenal cortex, not the anterior pituitary gland.
Identify the endocrine gland within the abdominal cavity, near the small intestine.
- A. Adrenal gland
- B. Hypothalamus
- C. Pancreas
- D. Thyroid gland
Correct Answer: C
Rationale: The correct answer is C: Pancreas. The pancreas is an endocrine gland located in the abdominal cavity near the small intestine. It secretes hormones like insulin and glucagon that regulate blood sugar levels. The adrenal gland (A) is located on top of the kidneys, the hypothalamus (B) is in the brain, and the thyroid gland (D) is located in the neck. These glands are not near the small intestine, making them incorrect choices.
Cells that respond to peptide hormones usually do so through a sequence of biochemical reactions involving receptor and kinase activation. In order for cells to respond, it is necessary for first and second messengers to communicate. This is possible because ________.
- A. peptide hormones always enter the cell membrane and elicit a response without assistance from other messengers
- B. hormones alter cellular operations through stimulation of a gene directly
- C. G protein acts as the link between first and second messengers
- D. the hormone receptor complex moves into the cytoplasm as a unit
Correct Answer: C
Rationale: The correct answer is C: G protein acts as the link between first and second messengers.
Rationale:
1. Peptide hormones cannot enter the cell membrane due to their large size.
2. Hormones do not directly stimulate genes; they act through signaling pathways.
3. G proteins are key in transmitting signals from hormone receptors to second messengers, facilitating cellular responses.
4. The hormone receptor complex typically stays on the cell membrane to initiate signaling cascades.