What Hormones Are Directly Involved With the Sympathetic Response? How Do Target Organs Respond?
If a neuron receives a large enough signal, the resting potential changes, producing an electrical impulse called an action potential. Once an impulse begins, it moves down the axon until it reaches the axon terminal.
The same hormone may play a role in a variety of different physiological processes depending on the target cells involved. For example, the hormone oxytocin promotes uterine contractions in women in labor. It is also important in breastfeeding, and may be involved in the sexual response and in feelings of emotional attachment in both males and females. In general, the nervous system involves quick responses to rapid changes in the external environment, and the endocrine system is usually slower acting—taking care of the internal environment of the body, maintaining homeostasis, and controlling reproduction.
Other emotional responses influenced by these higher brain areas include fainting, breaking out in a cold sweat, and a racing heart rate (Pappano AJ., 2001).
The heart produces the hormone atrial natriuretic peptide, which functions to reduce blood volume, pressure, and Na+ concentration. The gastrointestinal tract produces various hormones that aid in digestion. The kidneys produce erythropoietin. The thymus produces hormones that aid in the development of the immune system. The gonads produce steroid hormones, including testosterone in males and estrogen and progesterone in females. Adipose tissue produces leptin, which promotes satiety signals in the brain.
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