The field of biology is such which encompasses a wide variety of animals, plants, and other living organisms. What each of these organisms is made of is essentially a bunch of chemicals. There are different sets of chemicals for each specific purpose.
When the chemicals are used to transmit some message or get a response from a specific part of the body of an organism, this is where hormones and neurotransmitters come into play. On the face of it, their purpose might seem similar, however, they have vastly different functionalities.
Hormones vs Neurotransmitters
The main difference between hormones and neurotransmitters is that hormones are used by the endocrine system and released into the bloodstream to act on some neighboring target while neurotransmitters are used by the nervous system and released into the synaptic gap, where it targets the post-synaptic nerve cell.
Hormones are the chemical messengers that are directly put into the bloodstream. Hormones are responsible for most of the bodily changes that occur in the body. Some examples of such bodily changes are growth and development, metabolism, sexual function, cognitive abilities, etc. However, other than these, hormones are responsible for things such as adrenaline which prompts the fight or flight response. Hormones are found in both, plants and animals.
Neurotransmitters, on the other hand, are chemical messengers that are used by the nervous system to transmit messages from one place to another. The target location can be nerves, muscles, or glands. It is important to note that neurotransmitters are only found in animals.
Comparison Table between Hormones and Neurotransmitters
| Parameters of Comparison | Hormones | Neurotransmitters |
| Availability | Found in both plants and animals. | Found only in animals. |
| System used | Uses the endocrine system. | Uses the nervous system. |
| Mode of transportation | Is injected into the bloodstream. | Goes via the synaptic gap. |
| Function | Controls growth, development, reproduction, etc. | Transmits messages between nerve cells. |
| Functionality speed | Can take hours or even days. Slow. | Is every fast, works in milliseconds. |
What are Hormones?
Hormones are the chemical messengers that are used by the endocrine system to regulate specific organs or tissues. The endocrine system does this by releasing hormones into the bloodstream. Usually, the organ or tissue to be regulated is not very far from the gland which releases the hormone. When the hormone reaches the target location via the bloodstream, there are special receptors that are able to recognize only that chemical and nothing else. On reaching the target, the receptors receive the hormone and a chemical reaction takes place, thus causing the desired result which is required by the body.
There are numerous hormones and each of them has different purposes. Hormones are secreted by organs called ‘glands’. The major glands which regulate our day to day functions are:
- Pituitary gland
- Hypothalamus
- Pineal gland
- Adrenals
- Testes
- Ovaries
- Parathyroids
The pituitary gland is the most important gland in our body. It is also known as the ‘master gland’. It is important in regulating body functions and well being. It controls the functioning of all other glands, hence the name ‘master gland’.
The most common examples of hormones present in the body are estrogen, progesterone, testosterone, adrenaline, serotonin, cortisol, etc.
When a hormone is secreted in great amounts or when it is secreted in a lesser amount than required, it causes a chemical imbalance in the body. The most common example of this is insulin. Insulin helps maintain the sugar level in our blood and released by the pancreas. When insulin is released in large amounts, it absorbs too much sugar and causes the liver to release less glucose. This leads to a condition called hypoglycemia. Again, when insulin is released in insufficient amounts, then there is an excess of sugar in our blood, and thus causes a condition called diabetes.
Hormonal secretion is largely determined by genes, however, it can be maintained well to a large extent by maintaining a proper diet and regular exercise.
What are Neurotransmitters?
Neurotransmitters are the chemical messengers that are used by the nervous system to transmit messages from one nerve cell to another. To understand how these chemicals work, we will have to understand how the nerve cells are arranged. There are two ends of a nerve cell. One end is called ‘Axon’ and the other end is called ‘Dendrite’. The cells are arranged in such a way, that the axon faces the dendrite. Now, there is a small gap between these two cells and this is where neurotransmitters are used.
Neurotransmitters are chemicals that are Axon terminal of one cell and received by the dendrite terminal of another cell. These neurotransmitters are the mode of transmission of information between the gaps of the nerve cells.
Neurotransmitters are classified into three major categories, amino acids, peptides, and monoamines. Other types of neurotransmitters are gasotransmitters, trace amines, purines, catecholamines, etc.
There are quite a few diseases associated with neurotransmitters. The most common disease being Parkinson’s disease. This disease is a nervous system disorder that is progressive in nature, which means that it increases over time. It starts with parts of the body suffering small tremors accompanied by some stiffness and slowing of movement. This is a lot dependent on the genetics of the person. This occurs mainly when the nerve cells in the brain die out, and there is a loss of dopamine.
There are ways to keep the nervous system healthy. The best ways being to exercise regularly, get a lot of sleep and proper rest, prevent smoking, and having a balanced diet.
Main Differences Between Hormones and Neurotransmitters
- The main difference between hormones and neurotransmitters is that hormones are chemicals used by the endocrine system for various organs or tissues and neurotransmitters are chemical messengers to transfer information through the synaptic gap.
- Hormones are found in both, plants and animals. Neurotransmitters are found in animals only.
- Hormones are transmitted via the bloodstream. Neurotransmitters travel in the synaptic gap.
- Hormones control development, physical growth, cognitive ability, etc. Neurotransmitters are used to only transmit messages in the nervous system.
- Hormones are slow and can even take days to act. Neurotransmitters are fast and work in milliseconds.
Conclusion
Both Hormones and Neurotransmitters are chemical messengers and play a very delicate role in the body. Any imbalance in either causes serious diseases and imbalance in the body. Although both work in different systems in the body, their correlation and synchronization is important. Exercising regularly, eating a balanced diet, and getting proper rest is the key to keep both of these systems healthy and function properly.
References
- https://www.annualreviews.org/doi/abs/10.1146/annurev.ne.14.030191.001251?journalCode=neuro
- https://books.google.co.in/books?hl=en&lr=&id=OWxLaKew8sQC&oi=fnd&pg=PP1&dq=hormones&ots=bRsmaFXYnA&sig=UwVqH_KZy-YbpOsPI_vMaqJzlh0&redir_esc=y#v=onepage&q=hormones&f=false