By One of the main differences between the two chemicals is that hormones have a wide range of influence, while neurotransmitters do not. Learn about other key differences.
In order to function properly, the body needs hormones and neurotransmitters . Hormones are secreted by endocrine glands and are involved in regulating different body functions. Neurotransmitters, on the other hand, allow communication between neurons by crossing the synaptic space.
These chemicals carry signals from one part of the body to another. Both chemicals are important for the physiological stability of the body. They control a wide variety of physical and psychological functions, including our mood, our eating patterns, our ability to learn, and our sleep cycles.
What are neurotransmitters?
They are endogenous chemicals that mediate communication between neurons throughout the central and peripheral nervous system . They enable the brain to perform a variety of functions through the process of chemical synaptic transmission. In addition, these substances are an important part of our lives and our daily functions and activities.
Thus, neurotransmitters are necessary to boost and balance signals in the brain and to maintain its functioning. They help manage automatic responses such as breathing and heart rate. They also have psychological functions such as learning, managing mood, fear, pleasure and happiness.
What are hormones?
They are chemical substances secreted by a cell or group of cells in order to exert physiological effects on other cells in the body. Hormones can act locally or remotely, by spreading to all the tissues of the body and by acting on those cells that have specific receptors for them.
They also intervene in the regulation of growth. They are capable of influencing the cytoarchitecture and structure of the brain permanently during development, from the fetal period to the end of adolescence. They also participate in the appearance of a wide range of behaviors, moods and organic processes.
The main differences between hormones and neurotransmitters
The human body is an interconnected network of essential life systems, where these two substances play fundamental roles, although at different levels and in different regions. Although they collaborate in maintaining the body’s processes, they have several differences.
1. Stimulation
Hormones are able to stimulate and regulate organs and tissues, and therefore influence different parts of the body. Neurotransmitters, on the other hand, only stimulate postsynaptic neurons, that is, they act only on nerve cells.
2. Production system
Unlike hormones, which are produced by the endocrine system , neurotransmitters are synthesized by the nervous system.
3. Release points
The adrenal glands, kidneys, thyroid and other areas are responsible for secreting hormones. In the case of neuronal transmitters, the terminal buttons of nerve cells are responsible for their release.
4. Function
In contrast to neurotransmitters, which are involved only in the emission of nerve signals, hormones have diverse functions and intervene in the control of growth, development and reproduction.
5. Transmission mode
Hormones travel through the circulatory system, which allows them to travel long distances. Neurotransmitters, on the other hand, send signals through synaptic clefts.
6. Range of action
Hormones have a long range . This means that their target organs (site of action of a hormone) are usually at a certain distance from the gland that secretes them. Neurotransmitters, on the other hand, have a very limited range of action, since they affect the cells that connect through synaptic junctions.
7. Transmission speed
An important difference between hormones and neurotransmitters is the speed of transmission. Since the former operate to reach distant cells or tissues, the transmission of the signal is much slower. In contrast, the diffusion of the signal of neurotransmitters, which only send messages between neurons, is faster.
8. Affected tissues
The range of tissues affected by neurotransmitters is much smaller than that of hormones. The action of the latter tends to occur in multiple regions of the body. Therefore, they tend to produce coordinated responses from several organs or tissues, as in the case of adrenaline , which affects muscles, connective tissue, and the liver.
9. Living beings in which they are present
Another key difference between hormones and neurotransmitters is that the former are produced in many other living organisms, such as plants. In contrast, the latter are molecules unique to animals.
10. Classification by structure
Hormones are classified , according to their structure, into the following groups:
- Peptide/protein: These are chains of amino acids, such as insulin and glucagon.
- Steroids: steroids that act as hormones. They are mainly classified into five groups: glucocorticoids, mineralocorticoids, androgens, estrogens, and progestogens.
- Amino acids: these are hormones derived from amino acids such as thyroxine or melatonin.
On the other hand, there are different types of neurotransmitters , they can be classified as follows:
- Peptides: small chains of amino acids, including endogenous opioids, cholecystokinin, vasopressin, substance P, among others.
- Purines: This category includes ATP (adenosine triphosphate) and adenosine.
- Gases: As their name suggests, these are gases that function as neurotransmitters. Among them, nitric oxide and carbon monoxide stand out.
- Amino acids: These include glutamate, GABA, glycine, and aspartate. Glutamate is typically excitatory, whereas GABA and glycine are inhibitory.
11. Examples
The main hormones are the following (Walters, 2020):
- Androgens: Cause male sexual characteristics. They are important in sexual drive in both sexes and are linked to social aggression and dominance.
- Estrogens: trigger the development of female secondary sexual characteristics during puberty. They regulate female fertility, which is linked to learning and memory in both sexes.
- Endorphins: reduce pain and induce pleasure. They are released when one is under stress. Their effects are similar to natural opiates such as morphine.
- Melatonin: promotes sleep and helps regulate the circadian rhythm.
Among the neurotransmitters we can find the following (Walters, 2020):
- Acetylcholine : stimulates muscle contractions and is used in the brain to regulate memory, sleep and dreaming.
- Dopamine : involved in movement, motivation and emotion. It produces feelings of pleasure when released by the brain’s reward system . It is also involved in learning.
- Endorphin : Released in response to behaviors such as vigorous exercise, orgasm, and eating spicy foods.
- Gamma-aminobutyric acid ( GABA ): is the main inhibitory neurotransmitter in the brain, reduces arousal and is involved in sleep.
- Glutamate : This is the most common neurotransmitter. It is excitatory and is released in more than 90% of the synapses in the brain.
- Serotonin : Involved in many functions including mood, appetite, sleep, and aggression.
Collaborative and complementary work
In conclusion, hormones and neurotransmitters are important substances for our body. Their functions are integrated in order to maintain a balance in the body and thus allow us to respond more quickly to the different situations that life presents to us.
Despite having different origins, particular modes of action and specific influences on key areas of the body, both work very well together. From mood to sex, both substances intertwine to preserve our life, development, health and well-being.