PHY3181 Lecture Notes - Lecture 19: Noradrenergic Cell Groups, Hypophyseal Portal System, Locus Coeruleus
Document Summary
Stress = a state of threatened or perceived as threatened, homeostasis: physiological nutritional deficiency, osmotic challenge, psychological phobias, environmental thermal, oxidative stress. Body perceives stress and processes stress responses. Hpa axis = corticotropin releasing hormone (crh) acth cortisol. Sympathetic activity = corticotropin releasing hormone (crh) noradrenaline adrenaline. Corticotropin releasing hormone (crh) from parvocellular paraventricular nucleus acth in the anterior pituitary cortisol in the adrenal cortex. Crh and adg from parvocellular paraventricular nucleus activation of locus coeruleus and noradrenergic cell groups in pons and medulla adrenaline in the adrenal medulla. Adh and oxytocin (oxy) from the parvocellular paraventricular nucleus, co-localised with crh released into hypophyseal-portal system to enhance properties of crh. Paraventricular nucleus (pvn) = key brain region that regulates stress response. Extensive connections in the hypothalamus and brainstem. Role in autonomic control in the regulation of metabolism, growth, reproduction and other autonomic functions.