Function of the hypothalamus | Hypothalamic neurosecretory cells | Hypothalamic hypophysiotropic hormones | Complexities of the hypothalamic-pituitary interactions | Adenohypophyseal hormones |
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Name the three areas of the medial basal hypothalamus that are referred to the endocrine hypothalamus
Median eminence, arcuate nucleus, VMH
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What are the two types of neurosecretory cells
Magnocellular and Parvicellular
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What is the function of hypophysiotropic hormones
To modulate the release of the anterior pituitary hormones
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Give some examples to explain that hypothalamic hormones are multifunctional
1)TRH stimulates TSH and prolactin, 2)SOM inhibits GH release and TSH and PRL
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What hormone does TRH release from the anterior pituitary?
TSH
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Which is the main gland that contacts the median eminence?
Pituitary
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What are the functions of the magnocellular cells
To release neurohormones into the circulatory system
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What are the six well established hypophysiotropic homrones that regulate release of anterior pituitary
TRH,CRH, GnRH, GHRH, somatostatin (SOM), dopamine
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Give some examples how the pituitary hormones can be transported back into the hypothalamus to act as neruomodulator
1)retrograde axonal transport 2) efferent portal vessels, via blood flow from the pituitary to the hypothalamus3)peripheral blood
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What hormone release is inhibited by dopamine?
prolactin
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Name some of the functions controlled by the hypothalamus
Growth, reproduction, metabolism, stress, temperature control, emotional behavior, motivational arousal, fluid balance, circadian rhythm
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What are the functions of the parvicellular cells
To release hypothalamic hormones into the hypophyseal portal system
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what is known about the control of alpha-MSH release from the anterior pituitary
GABA and dopamine inhibits alpha-MSH release. CRH, HT and NE stimulate alpha-MSH release. No hypophysiotropic hormone other than these classic neurotransmitters has been identified to regulate alpha-MSH secretion.
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Explain why not all the hypothalamic hormones are secreted into the portal system
Hypothalamic hormones act as neuropeptides to modulate neuronal excitability influencing neurotransmitters release because they can be released from other regions other than the hypothalamus.
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What hormones does GnRH release from the anterior pituitary?
LH and FSH
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Which other brain regions give neuronal information to the hypothalamus
Amygdala,hippocampus, spinal cord
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What is a neuroendocrine transducer
Convert neuronal input into hormonal output
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What classic neurotransmitter also serves as a hypophysiotropic hormone?
Dopamine
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Give an example how pituitary hormones release can be influenced by neuropeptide, neurotransmitters as well as hypothalamic hypophysiotropic hormones
It has been shown that GABA is present in the hypophyseal portal blood and that GABA receptor are present in the cells of the pituitary gland. GABA regulates GH secretion and influences TSH secretion.
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What hormones does CRH release from the anterior pituitary?
ACTH and beta-endorphin
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Name some essential information that the hypothalamus can sense from the bloodstream
Temperature and hormone levels
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Give four examples of neuroendocrine transducer
1)magnocellular neurons that release oxytocin2)the parvicellular neurons that secrete releasing/inhibiting hormones into the hypophyseal portal system30 the adrenal medulla tha responds to sympathetic stimulation with the release of catecholamines4) the p
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What two hormones are NOT hypophysiotropic hormones because they are released from the magnocellular neurons in the posterior pituitary directly into the circulatory system?
vasopressin and oxytocin
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Explain the concept of negative feedback
Production of hypothalamic hormones can be influenced by other hormones produced by the target glands
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What hormone release is stimulated by GHRH and inhibited by somatostatin (SOM)?
Growth hormone (GH)
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