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19 Cards in this Set
- Front
- Back
Where is the hypothalamus located? |
Under the floor of the third ventricle, extending from the optic chiasm and lamina terminalis anteriorly. It is bordered laterally by the optic tracts and posteriorly by the mammillary bodies. |
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What are the functional zones of the hypothalamus? |
1. Periventricular 2. Medial 3. Lateral |
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The periventricular zone of the hypothalamus contains which nuclei? |
1. Suprachiasmatic nucleus (circadian rhythm) 2. Magnocellular - endocrine control 2. Parvocellular - endocrine control |
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The medial nuclei of the hypothalamus are involved in? |
Maintaining homeostasis and controlling reproduction, and also autonomic control and is critical in stress response |
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The lateral hypothalamus controls what? |
Food intake and the sleep-wake cycle (through orexin, also known as hypocretin) and motivated behaviour |
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Which system regulates the release of oxytocin and vasopressin? |
The magnocellular system |
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Where do the cells of the magnocellular system project? |
Posterior pituitary; together they constitute the neurohypophysis |
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Where are the cells of the magnocellular system located? |
Paraventricular nucleus and supraoptic nucleus; they are large-diameter hypothalamic neurons |
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What is the role of the parvocellular system? |
To regulate pituitary hormone release by neurovascular transmission |
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Where are the nuclei of the parvocellular system located? |
They comprise small-diameter neurons in several hypothalamic nuclei in the periventricular zone |
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Where do neurosecretory cells of the parvocellular system project? |
To the median eminence, where their nerve terminals release peptidesinto the hypothalamo-hypophysial portal system, which carry the signals to the anterior pituitary gland |
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Which regulatory hormones are produced in the paraventricular nucleus? (3) |
1. CRH 2. TRH 3. PRH, TRH, oxytocin |
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Where is growth hormone releaseing hormone (GH-RH) produced? |
In arcuate (infundibular) neurons, and its release into the hypophyseal portal system triggers GH secretion from somatotropes in the anterior pituitary gland |
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Which hormone inhibits the release of GH? |
Somatostatin, also known as growth-hormone release-inhibiting hormone |
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Where is somatostatin produced? |
Periventricular nucleus |
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Where is prolactin produced? |
By lactotrophic cells in the pituitary; it is released in response to prolactin releasing hormone (PRH) |
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Where are the cells producing Gonadotropin Releasing Hormone (GnRH) located? |
Preoptic nucleus |
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Effect of dopamine on prolactin? |
Inhibitory |
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Which part of the hypothalamus is important in motivated behaviour (e.g., defensive behaviour)? |
Medial zone of the hypothalamus; thus, lesions in this region may result in behavioural dyscontrol |