The brain of a human is directly connected to the organs of the body. In this way, all these parts tend to affect the way a person behaves. The genes play a vital role when it comes to human behavior. For example, some behaviors are species specific while others are often breed true. Behaviors can also change in response to alterations in biological structures or processes. Some behaviors run in families while others have an evolutionary history that persists across related species. There are certain parts of the human body that possess vital roles. The first vital part of the body is the olfactory bulb. This is a structure that is found on the forebrain of all vertebrates. The olfactory is a vital part of the body that works on olfaction. Olfaction is simply the perception of odors or smell. In human beings, this structure is mainly found on the bottom of inferior side of the brain. This is unlike the case in animals where the olfactory appears on the upper side of the brain (Margolis, 1988).
How the human body is structured plays a big role in his or her general behavior. Furthermore, the nervous system appears as the basic part of the body that the psychologists use to verify the general characteristics of a human. The nervous system appears as an instrumental part of the body that transmits orders from the spinal cord to the brain. This gives it supremacy over other many organs and structures of the body (Halasz, 1990).
Going back to the olfactory system, it should be noted that this part is also a crucial part of the body. The first part of the olfactory is the olfactory bulb. This structure is divided into two basic parts. These include the main olfactory bulb and the accessory olfactory bulb. The main olfactory bulb has multilayer that also serve fundamental purposes. These include the transmission of smell information from the nose to the brain which makes it vital for the proper sense of smell. It also acts as a neural circuit with one source of sensory input and the other a sensory output so it essentially functions as a filter. It can also receive top down information from the brain. Hence its functions can be taken as those of discrimination among odors, enhancement of sensitivity of odor detection, the filtration of many background odors in order to enhance the transmission of a few select orders and the permission of higher brain areas that are concerned with the arousal and attention to allow the modification of detection or the discrimination of odors (Davis, 1996).
The second part which is the partner olfactory bulb which is the second processing stage is mainly concerned with detection of odor and also the detection of looming danger.
The brain and the nervous system work closely together with the nervous system acting as a means by which the generated signals from the brain are transmitted to the recipient organ. Looking at the anatomy of the brain one would realize that it is made up of three major layers that’s the hind brain, the midbrain and the fore brain. The forebrain which is the most outer division of the human vertebrate is the part that contains the most complex neural network. This part of the brain has two major divisions which are the lower diencephalon which is houses the thalamus and the hypothalamus and the upper teleencephalon which houses the cerebrum (Rudolf, 2004).
The second part of the brain, the midbrain, situated between the forebrain and the hindbrain forms part of the brain stem. All sensory and motor information going to and from the forebrain and the spinal cord has to pass through this part of the brain.
The hindbrain being the interior most is very well protected. It is made up of cerebellum, reticular formation and the brain stem. The cerebellum plays an important role in sensory perception and motor output (Schünke, 1998).
The nervous system which is considered to be the most essential as the pathway of transmission of signals between the body organs and the brain has the neurons as the basic tissue and element. The neuron too is made up of the cell body, the axon and one or more dendrites that terminate in both the organs and the brain. The nervous system is divided into the central nervous system, the peripheral nervous system and the glandular nervous system.
Olfaction, which is the logic of smell, is interceded by specialized sensory cells of the nasal cavity of the human beings Olfaction normally takes place when the odorant molecules bind to the specialized olfactory cells. Odorants are the chemicals that initiate the olfactory process and are normally in very low concentrations. Olfaction and taste is a form of chemoreception. The olfactory system in vertebrates is made up of the olfactory sensory neuron in the olfactory epithelium. The mucus overlying the epithelium holds mucopolysaccharides, salts, enzymes and antibodies. The olfactory neuron can present a direct passage for contagion to pass into the brain hence the antibodies present would help prevent this (Seiden, 2000).
The olfactory bulb on its part has sensory neuron projections that axon to the brain within the olfactory nerve.
On the other hand gustatory reception is the feeling produced when a substance in the mouth reacts chemically with the taste receptors Taste buds which are the means by which humans perceive taste are also called gustatory calyculli. These taste buds are concentrated on top of the tongue. The taste buds can be found on the tongue within three different papillae and also at the back of the throat and the roof of the mouth .There are five basic tastes that is sweetness, sourness, saltiness, bitterness and umami. All of which the taste buds can differentiate into the different tastes by detecting the interaction between the different molecules and ions. Sweet, bitter and umami are normally triggered by binding of molecules to G protein coupled receptors on the cell membrane of the taste buds. When alkali metals and hydrogen ions enter the taste buds that’s when sourness and saltiness is perceived. Sweetness helps to identify energy rich foods hence the taste is said to be appetitive while on the other hand bitterness can be taken to mean the presence of poisons. So this system is very vital when it comes to the detection of useful and harmful foods hence it helps humans eat good food (Rugai, 1997).
Brain damage is the condition under which the brain cells are destructed or degenerated. Traumatic head injury is a category that has the greatest number of injuries following trauma caused physically or from head injury. Brain damage may be due to a variety of factors among them being illnesses, injuries and as a result of severe medical treatment. Other causes may include prolonged hypoxia. The body may respond differently to brain damage. Cytokinese in particular is known to be induced in response to brain injury.
Brain damage can manifest itself as impairment or disability that normally has great severity. These injuries can make one unable to separate daydreams from real memory .This condition is many a times only managed by proper medical care and rehabilitation. Occupational therapists and physiotherapists may be needed to help the patient recover. The likely hood of progress of the disorder depends upon the nature, location and the extent of the injury.
Anosmia is a disorder in which the olfactory system does not function as required. In this case, one would not be able to perceive any odor. It can be temporary or permanent in which case on can be so traumatized by the inability to detect smell. Temporarily Anosmia can be sourced by a blocked nose or infection while permanent Anosmia can be caused by the loss of olfactory receptor neurons in ones nose or by the damage of olfactory receptor cells due to injury to the brain. One can be diagnosed of Anosmia by using the tests on Acetylcysteine. Anosmia may be on very rare occasions be a precursor of brain related diseases such as Parkinson’s disease and Alzheimer’disease.Use of certain categories of nasal sprays could also cause permanent Anosmia.
Ageusia is the inability to detect taste by the tongue. This is with regard to sweetness, bitterness, sourness, saltiness and umami. This is condition in particular is rare as compared to hypogeusia (partial loss of taste) and dysgeusia (distortion of taste).This condition could be due to the impairment of the endocrine systems or by medicinal side effects. Ageusia could also be caused by local damage and inflammation that interferes with the local buds or the damage of the local nervous system such as that result from radiation therapy. The most serious of all these causes is neurology damage which is as a result of the damage of the tissues of the nerves that support the tongue.
In order to diagnose one with Ageusia the doctor will attempt to determine the minimum level of a chemical that a patient can detect and be able to differentiate. Among the methods used include the “sip, spit and rinse” test in conjunction with direct application of chemicals to the tongue.
In conclusion, the brain, nervous system, the olfactory mechanism and the taste mechanism play a very important role in the determination of human’s behavior.
References
Davis, J. L. Olfaction: A Model System for Computational Neuroscience. of MIT Press. Copyright. .
Halasz, N. (1990). The vertebrate olfactory system: chemical neuroanatomy, function, and development. Akadémiai Kiadó.
Margolis, F. L. (1988). Molecular neurobiology of the olfactory system: molecular, membranous, and cytological studies. Plenum Press.
Nieuwenhuys, R. The Human Central Nervous System. Springer.
Rugai, N. (1997). A Soft Computational Approach to the Modeling of the Taste System. of ProQuest. Copyright. .
Schünke, M. (1998). Thieme atlas of anatomy: Head and neuroanatomy. Vol. 3. Thieme.
Seiden, A. M. (2000). Taste and Smell Disorders. Thieme.
