Hypothalamus MC Practice Questions Flashcards
Which of the following best explains how vasopressin (AVP) contributes to blood pressure regulation during hypovolemia?
A. It stimulates renin release from the kidneys
B. It increases aquaporin expression in the proximal tubule
C. It causes vasodilation via V2 receptors in the collecting duct
D. It causes vasoconstriction via V1 receptors on vascular smooth muscle
E. It directly stimulates aldosterone release from the adrenal medulla
D. It causes vasoconstriction via V1 receptors on vascular smooth muscle
A lesion to the ventromedial nucleus (VMN) of the hypothalamus would most likely result in which of the following outcomes?
A. Reduced thirst sensation
B. Hyperphagia and obesity due to loss of satiety signaling
C. Anorexia due to increased activity of the lateral hypothalamic area
D. Enhanced release of corticotropin-releasing hormone (CRH)
E. Inappropriate ADH secretion and hyponatremia
B. Hyperphagia and obesity due to loss of satiety signaling
Which of the following structures is located outside the blood-brain barrier and allows the hypothalamus to monitor blood osmolality?
A. Suprachiasmatic nucleus
B. Arcuate nucleus
C. Subfornical organ
D. Ventromedial nucleus
E. Lateral geniculate nucleus
C. Subfornical organ
Which hormonal pair is synthesized in the hypothalamus and released from the posterior pituitary?
A. CRH and ACTH
B. TRH and TSH
C. Oxytocin and vasopressin (AVP)
D. GH and IGF-1
E. Prolactin and dopamine
C. Oxytocin and vasopressin (AVP)
In response to infection, which pathway leads to fever generation via hypothalamic activity?
A. Cytokine activation of COX-2 in the preoptic area increases AVP secretion
B. Interleukin-1 stimulates prostaglandin E2 production, which raises the hypothalamic set point
C. ACTH release from the hypothalamus increases cortisol and inhibits thermogenesis
D. Leptin stimulation of the anterior hypothalamus increases basal metabolic rate
E. Oxytocin promotes shivering thermogenesis in the posterior hypothalamus
B. Interleukin-1 stimulates prostaglandin E2 production, which raises the hypothalamic set point
A patient with central diabetes insipidus is most likely to have dysfunction in which hypothalamic area?
A. Arcuate nucleus
B. Paraventricular and supraoptic nuclei
C. Lateral hypothalamic area
D. Ventromedial hypothalamus
E. Suprachiasmatic nucleus
B. Paraventricular and supraoptic nuclei
Which of the following correctly matches the hormone to its regulatory hypothalamic neurotransmitter?
A. Prolactin – stimulated by dopamine
B. Growth hormone – inhibited by GHRH
C. TSH – stimulated by GnRH
D. ACTH – stimulated by CRH
E. LH – inhibited by TRH
D. ACTH – stimulated by CRH
Which of the following best describes the role of the arcuate nucleus in energy balance?
A. It produces oxytocin to stimulate uterine contractions
B. It regulates circadian rhythm through light detection
C. It integrates leptin and ghrelin signals to modulate hunger and satiety
D. It promotes thermogenesis through the anterior hypothalamus
E. It monitors blood osmolality to trigger thirst
C. It integrates leptin and ghrelin signals to modulate hunger and satiety
A researcher blocks V2 receptors in a test subject. Which of the following physiological outcomes would most likely be observed?
A. Hypertension due to excess vasoconstriction
B. Increased water reabsorption and concentrated urine
C. Polyuria and low urine osmolality
D. Elevated aldosterone levels and hyperkalemia
E. Increased thirst despite decreased serum osmolality
C. Polyuria and low urine osmolality
Which of the following statements best describes the role of the hypothalamus in coordinating the stress response?
A. It secretes ACTH to directly stimulate the adrenal cortex
B. It releases cortisol in response to sympathetic activation
C. It integrates emotional input from the limbic system to activate CRH release
D. It regulates AVP to inhibit immune cell function
E. It causes vasodilation in skeletal muscle to reduce sympathetic output
C. It integrates emotional input from the limbic system to activate CRH release
A 32-year-old woman presents with excessive thirst and urination. Her urine is very dilute, and serum sodium is elevated. Desmopressin administration reduces urine volume and increases urine osmolality. Which is the most likely cause of her symptoms?
A. Nephrogenic diabetes insipidus
B. Primary polydipsia
C. Syndrome of inappropriate ADH secretion (SIADH)
D. Central diabetes insipidus
E. Addison’s disease
D. Central diabetes insipidus
A patient with a hypothalamic tumor compressing the ventromedial nucleus is most likely to develop which of the following symptoms?
A. Reduced thirst sensation
B. Hyperphagia and rapid weight gain
C. Increased aggression and risk-taking behavior
D. Dehydration with polyuria
E. Decreased libido and fertility
B. Hyperphagia and rapid weight gain
A 68-year-old man is brought to the hospital confused and lethargic. Labs show hyponatremia, low serum osmolality, and concentrated urine. ADH levels are elevated despite low plasma osmolality. Which condition best explains these findings?
A. Diabetes insipidus
B. Syndrome of inappropriate ADH secretion (SIADH)
C. Hyperaldosteronism
D. Central pontine myelinolysis
E. Pheochromocytoma
B. Syndrome of inappropriate ADH secretion (SIADH)
A 27-year-old male with a history of trauma develops decreased libido and erectile dysfunction. Blood tests reveal low LH and FSH. MRI shows damage to the arcuate nucleus. Which hormone is most likely undersecreted by the hypothalamus?
A. TRH
B. CRH
C. GnRH
D. GHRH
E. ADH
C. GnRH
A newborn fails to thrive and exhibits no weight gain. Genetic testing reveals leptin receptor deficiency. Which of the following hypothalamic effects is most likely impaired?
A. Inhibition of NPY/AgRP neurons and stimulation of POMC/CART neurons
B. Stimulation of GnRH neurons in the preoptic area
C. Activation of thermogenic pathways in the posterior hypothalamus
D. Suppression of oxytocin release during breastfeeding
E. Vasoconstriction of cerebral vessels in the anterior hypothalamus
A. Inhibition of NPY/AgRP neurons and stimulation of POMC/CART neurons
During labor, a woman receives an epidural that temporarily blocks hypothalamic-pituitary signals. Which of the following outcomes would most likely be observed?
A. Decreased CRH and subsequent cortisol secretion
B. Decreased oxytocin release, leading to reduced uterine contractions
C. Increased vasopressin secretion, causing water retention
D. Enhanced prolactin secretion due to dopamine inhibition
E. Elevated ACTH release from the posterior pituitary
B. Decreased oxytocin release, leading to reduced uterine contractions
A patient with a pineal gland tumor affecting light perception presents with insomnia and disrupted sleep-wake cycles. Which hypothalamic nucleus is most likely affected?
A. Arcuate nucleus
B. Supraoptic nucleus
C. Suprachiasmatic nucleus
D. Paraventricular nucleus
E. Ventromedial nucleus
C. Suprachiasmatic nucleus
A 10-year-old girl presents with delayed puberty. Lab tests reveal low LH and FSH, and GnRH stimulation fails to increase their levels. MRI shows a lesion in the median eminence of the hypothalamus. Which best explains this?
A. Disruption of portal blood flow to the anterior pituitary
B. Direct destruction of anterior pituitary cells
C. Overproduction of prolactin inhibiting LH/FSH
D. Inhibition of the suprachiasmatic nucleus
E. Stimulation of the lateral hypothalamic area
A. Disruption of portal blood flow to the anterior pituitary
