in response to an acute stressor epinephrine is released from which structure
the adrenal medulla
title: Norepinephrine transporter text: neuron. NETs are located away from the synapse, where norepinephrine is released. They are found closer to the plasma membrane of the cell. This requires norepinephrine to diffuse from the site it is released to the transporter for reuptake. Norepinephrine transporters are confined to the neurons of the sympathetic system, and those innervating the adrenal medulla, lung, and placenta. Regulation of NET function is complex and a focus of current research. NETs are regulated at both the cellular and molecular level post-translation. The most understood mechanisms include phosphorylation by the second messenger protein kinase C (PKC). PKC has been shown title: Acute stress reaction text: colloquially known as the "fight or flight" response, indicated by accelerated pulse and respiration rates, pupil dilation, and a general feeling of anxiety and hyper-awareness. This is caused by the release of epinephrine and norepinephrine from the adrenal glands. The epinephrine and norepinephrine strike the beta receptors of the heart, which feeds the heart sympathetic nerve fibers in order to increase the strength of heart muscle contraction; as a result more blood gets circulated, increasing the heart rate and respiratory rate. The sympathetic nervous system also stimulates the skeletal system and muscular system in an effort to pump more blood title: Acute stress reaction text: locus ceruleus is minimal. A novel stimulus, once perceived, is relayed from the sensory cortex of the brain through the thalamus to the brain stem. That route of signaling increases the rate of noradrenergic activity in the locus ceruleus, and the person becomes alert and attentive to the environment. If a stimulus is perceived as a threat, a more intense and prolonged discharge of the locus ceruleus activates the sympathetic division of the autonomic nervous system (Thase & Howland, 1995). The activation of the sympathetic nervous system leads to the release of norepinephrine from nerve endings acting on the heart, title: Fight-or-flight response text: Fight-or-flight response The fight-or-flight response (also called hyperarousal, or the acute stress response) is a physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival. It was first described by Walter Bradford Cannon. His theory states that animals react to threats with a general discharge of the sympathetic nervous system, preparing the animal for fighting or fleeing. More specifically, the adrenal medulla produces a hormonal cascade that results in the secretion of catecholamines, especially norepinephrine and epinephrine. The hormones estrogen, testosterone, and cortisol, as well as the neurotransmitters dopamine and serotonin, also affect how title: Adrenergic nerve fibre text: Adrenergic nerve fibre An adrenergic nerve fibre is a neuron for which the neurotransmitter is either adrenaline (epinephrine), noradrenaline or dopamine. These neurotransmitters are released at a location known as the synapse, which is a junction point between the axon of one nerve cell and the dendrite of another. The neurotransmitters are first released from the axon and then bind to the receptor site on the dendrite. Adrenergic nerve terminals are found in the secondary neurons of the sympathetic nervous system, one of two deviations of the autonomic nervous system which is responsible for the fight-or-flight response. This system increases