Thirst is the craving for fluids and essential for fluid balance. Body detects thirst when water volume falls below threshold or osmolite concentration increases. Two types exist: extracellular thirst from blood volume loss and intracellular thirst from osmolite concentration
Neurohormones are hormones produced by neuroendocrine cells into blood. Can function as neurotransmitters or local messengers. Synthesis and release are co-regulated by hormonal, local and synaptic signals
GnRH is a hormone that regulates reproductive function through hypothalamus. GnRH neurons migrate and maintain reproductive function. GnRH pulse frequency varies during menstrual cycle. GnRH pulse frequency decreases with aging in postmenopausal women
Diencephalon sits above brain stem, forming by eighth week of gestation. Divided into thalamus, hypothalamus, epithalamus, and subthalamus. Located in third ventricle, part of forebrain
Hypothalamus forms part of diencephalon, located below hypothalamic sulcus. Divided into periventricular, medial, and lateral zones. Contains four regions: preoptic, supraoptic, tuberal, and posterior hypothalamic
Diencephalon is caudal part of forebrain occupying central brain region. Contains epithalamus, thalamus, subthalamus, metathalamus, hypothalamus and third ventricle. Third ventricle forms midline cleft between lateral ventricles and thalami