110 Questions
Which of the following is a function controlled by the hypothalamic nuclei?
Hunger
Which hormones are released by the supraoptic and paraventricular nuclei?
Oxytocin and arginine vasopressin
What is the role of the posterior pituitary gland?
To release oxytocin and AVP
Which hormone is also known as anti-diuretic hormone (ADH)?
Arginine vasopressin (AVP)
What is the effect of dopamine released from the arcuate nucleus and other nuclei?
Inhibits the release of prolactin
What is the role of the hypothalamic nuclei?
Maintenance of body weight
What is the function of oxytocin and arginine vasopressin (AVP)?
Release of hormones
What is the relationship between the hypothalamus and the autonomic nervous system?
Hypothalamus can control the autonomic nervous system
What is the blood brain barrier (BBB)?
A barrier that prevents the release of hormones into the brain
What is the function of the releasing hormone GHRH?
Stimulate the release of growth hormone
Which hormone is released directly into the bloodstream by axonal nerves in the posterior pituitary gland?
Oxytocin
What is the role of negative feedback pathways in hormone regulation?
To inhibit the release of hormones
What is the effect of cortisol on PNMT mRNA?
Increase
Which hormone can negatively feedback to inhibit the release of either GHRH or GH?
Insulin growth factor-1 (IGF-1)
What is the effect of somatostatin on the release of GH?
Inhibit the release of GH
What is the influence of a positive feedback pathway on the release of oxytocin?
Stimulate the release of oxytocin
Which of the following is a function controlled by the hypothalamus?
Thirst
What is the role of the hypothalamus in the stress response?
It activates the prefrontal cortex to release cortisol
What are the three nuclei that the hypothalamus is divided into?
Anterior, medial, and posterior
What is the output of the hypothalamus in response to stimuli?
ANS or Endocrine output via the pituitary gland
What is the effect of chronic stress on the prefrontal cortex?
It impairs its function
Which of the following is NOT a physiological function of the hypothalamus?
Visual perception
What systems does the hypothalamus coordinate to maintain homeostasis?
Multiple systems including endocrine and ANS
What is the role of negative feedback loops in hypothalamic responses?
To inhibit the hypothalamic response
What type of pathways to the hypothalamus are mostly unmyelinated?
Afferent and efferent pathways
What can initiate hypothalamic responses?
Cortical centers
What can be activated by the hypothalamus?
Cortical centers
What is the effect of cortisol on plasma glucose levels?
It elevates plasma glucose levels
What is the role of beta-endorphins in the stress response?
To reduce the response to pain
Which part of the brain is responsible for enhancing state of alertness in the stress response?
Locus ceruleus
What is the effect of extreme psychological stress on vagal activity?
It increases vagal activity
What is the effect of insulin overdose in Type I and Type II diabetics?
It results in hypoglycemia
What is the effect of beta-2-adrenergic receptor activation in the cardiovascular readjustments of the stress response?
It causes vasodilation
What is the effect of parasympathetic tone on cardiac output in the stress response?
It decreases cardiac output
What is the effect of hypnosis and meditation on stress reduction?
They decrease stress levels
What is the effect of chronic hypoglycemia on the stress response?
It elevates plasma glucose levels
What is the effect of overshoots and undershoots of body core temperature during a fever?
Less precise control of body core temperature
What can cause protein denaturation?
Heat
What is the effect of pro-inflammatory cytokines released during a fever?
Increased body temperature
What is the effect of stimulation of heating mechanisms during the 'Chills' phase of a fever?
Increased core temperature
What is the primary cooling mechanism in humans?
Eccrine sweat gland activation
What is the effect of cooling mechanisms during the 'Fever' phase of a fever?
Decreased core temperature
What is the state of a fever when the hypothalamic setpoint is reset back to normal?
Resolved
What is the effect of increased AVP levels during a fever?
Increased water conservation
What is the set point center for proper body temperature?
The hypothalamus
Which part of the hypothalamus controls reflex responses activated by warmth?
Anterior hypothalamus
What can cause heat production in the body?
Digestion of food
What is the normal body temperature by oral route?
37°C or 98.6°F
What is the process by which heat loss can occur through vaporization of water in respiratory passages and on skin called?
Evaporation
What is the effect of increased release of thyroid hormone in response to cold?
Increased heat production
What is the effect of beta-3-adrenergic receptor activation in response to cold?
Increased heat production
What is the process by which heat loss can occur through direct contact with a colder object called?
Conduction
What is the process by which heat loss can occur through emission of heat waves from the body called?
Radiation
What can lead to obesity?
Increased food intake without an equal amount of energy expenditure.
What signals influence appetite at the level of the hypothalamus?
Neural afferents, hormones, and metabolites.
Which mouse models produce hyperphagia and obesity when leptin or the leptin receptor is knocked out?
Both ob/ob and db/db mouse models.
What is the central integrator for appetite?
The ARC.
Which neurons in the ARC become activated and produce POMC protein in the presence of Anorexigenic signals?
POMC neurons
Which melanocortin receptors are most abundant in the CNS?
MC3R and MC4R.
What does MC4R do in the body?
It is responsible for actions on body weight and blood pressure.
What is the effect of exogenous leptin given to rodents?
It increases blood pressure.
What is the anorexigenic effect of CRH?
Decreases appetite
How does gastric distension affect appetite?
Decreases appetite
What is the effect of chewing gum on snacking on high calorie foods?
Decreases snacking
What is the anorexigenic effect of leptin on the body?
Decreases appetite
What is the effect of increased plasma leptin on the VMN?
Activates gene (TORC1)
What is the effect of low leptin in women?
Increase in amenorrhea
What is the effect of low leptin in men?
Reduces rate of sperm production
What hormone stimulates the lateral hypothalamus area (LHA) and can lead to hyperphagia?
Ghrelin
What is the effect of Neuropeptide Y (NPY) on cortisol releasing hormone (CRH)?
Inhibits release of CRH through activation of GABA-producing neurons
What hormone can lead to the release of ACTH/Cortisol under chronic low level stress conditions, such as stress eating?
Ghrelin
Which hormone stimulates higher centers to increase fat intake and decrease insulin secretion?
Galanin
What is the effect of Agouti-related peptide (AgRP) on the MC4R pathway and POMC?
Inhibits MC4R pathway and POMC
What can stimulate the HPA or increase appetite when given exogenously?
Chronic stress
What type of foods are highly consumed in Western society to alleviate stress?
Comfort foods (high dense, palatable foods)
What is the anorexigenic effect of CRH?
Potent
Which hormone influences short- and long-term regulation of appetite?
All of the above
What is the effect of vagotomy on ghrelin?
Inhibits ghrelin's ability to stimulate food intake
What happens to plasma ghrelin levels after gastric bypass surgery?
They decrease significantly
What is the mechanism behind the decrease in plasma ghrelin levels after gastric bypass surgery?
Decreased production and secretion of ghrelin
What is the effect of higher plasma cortisol levels on eating behavior?
Increased phasic responses to eating
What is the hypothesis behind the decrease in plasma ghrelin levels after gastric bypass surgery?
Direct contact between gastric mucosa and food is important for the production and secretion of ghrelin
What is the effect of gastric bypass surgery on fat accumulation?
It decreases fat accumulation
What is the effect of vagotomy on GH release?
Inhibits GH release
What type of information can chemoreceptors in gut mucosa send to the nucleus tractus solitarius (NTS) to influence appetite?
Nutrients, motility of tract, and neuroendocrine responses
What effect does distension of the stomach have on appetite?
Decreases appetite
What can shrink astrocytes surrounding POMC nerves to increase feelings of satiety and decrease appetite?
Increased plasma glucose
What protein was discovered in 2017 as an orexigenic protein?
Asprosin
What type of drugs have been used to stimulate appetite in patients with cancer cachexia?
5-HTR3 antagonists
What mediates the thirst response in the body?
Hypertonicity and hypovolemia
What regulates drinking water in the body?
Plasma osmolality and extracellular fluid volume
What can induce thirst independent of plasma osmolality?
Hemorrhage
What factors can contribute to the regulation of water intake besides physiological factors?
Social factors
Which type of receptor works through Gq to cause vasoconstriction?
V1
What is the function of the lateral hypothalamus in thirst response?
It triggers thirst response
What is the synthetic analog of vasopressin used to treat?
Neurogenic or central diabetes insipidus
What triggers milk ejection during breastfeeding?
Oxytocin
What is the reflex that triggers milk ejection called?
Neuroendocrine reflex
What type of receptors are activated by touch receptors in the nipple during breastfeeding?
Sensory afferents
What can cause waves of uterine contraction during childbirth?
A positive feedback loop involving oxytocin release
What is the effect of estrogen on sensitivity to oxytocin?
Increases sensitivity to oxytocin
Which system links the neuroendocrine, autonomic, and somatic motor systems?
Limbic system
What is the role of the amygdala in the stress response?
It stimulates the arcuate and paraventricular nuclei
What is the role of the hypothalamus in controlling thirst?
It releases hormones to promote thirst
Which type of receptor do most peptide hormones use to induce a specific signaling pathway?
GPCR
What is the mechanism of action of V2 receptors?
They work through Gs to increase cAMP
What is the role of 5-HTR3 antagonists in appetite stimulation?
They help to stimulate appetite
What is the purpose of anticholinergics and antihistamines in appetite stimulation?
They help to stimulate appetite
What is anamorelin used for in cancer patients?
To stimulate appetite
What is negative feedback in the context of hypothalamic control?
A mechanism by which a change in a variable leads to a response that counteracts the initial change
Test your knowledge of the hypothalamus and its role in controlling the autonomic nervous system with this quiz. Learn about the various nuclei involved in basic functions such as hunger, body weight maintenance, and body temperature regulation, as well as their link to behavior through the limbic system.
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