The olfactory epithelium is comprised of three different layers, which include supporting cells, olfactory receptor cells, and basal cells. Supporting cells aid in the production of mucous and they support the olfactory receptor cells. The basal cells are at the base of the epithelium and they are the source of newly developed receptors. Tiny hair like structures, called cilia, are found on the olfactory receptors and they are covered with mucous. If molecules entering the nostrils dissolve in the mucous, they stimulate the receptors and the sense of smell is evoked.
But how does it work? Olfaction, or smell, is the detection of chemicals in our surroundings. For humans, odors are processed in our olfactory epithelium. We have thousands of genes that act as odor receptors. Each of these genes act as a lock, with the odor molecules acting as the key.
Each type of neuron is randomly distributed across one of four zones within the olfactory epithelium. The information from this population coding is then reorganized, as these axons leave the epithelium and travel to the olfactory bulb, into a very specific, spatially organized map of activity across the several hundred kinds of receptors. The span between the 1000 types of receptor neurons, and discrimination amongst 10,000 odors, is bridged in the interpretation of the ratios and relationships of activity level across the population. The olfactory bulb was compared to an operators switchboard, and the process of odor identification was likened to determining which switchboard lights were flashing. The obvious question then becomes, what parts of the brain watch over the olfactory bulb, monitor its activity and interpret that activity?
When these particles bind to the receptor, the protein changes shape which causes an action potential in the neuron. This signal travels along the olfactory nerve (cranial nerve 1) to the olfactory bulb in the brain. From the olfactory bulb, neurons are sent to many different areas including through the anterior olfactory cortex to the priform cortex which is primarily used to identify the smell. Neurons also get sent to the amygdala which is associated with social functions such as identifying mates (this is a more primal instinctual use of smells). Neurons are also sent to the entorhinal cortex which links the smell to a specific memory.
The two main elements that are contained in the salivary glands are glandular secretory tissue and the supporting connective tissue. An example of the importance of saliva is how it brings substances into a solution so they can be tasted. Nerve growth as well as, epidermal growth factors are manufactured by the submandibular gland. The largest salivary gland is the parotid gland. Serous acini is what the majority of the gland is composed of.
There are three types of glandular secretion: merocrine, apocrine, and holocrine. Merocrine has a fluid product which secretes through the membrane of the cell. It is found in the pancreas and sweat glands. Apocrine has a cellular product and is secreted by half of the cell. It is found n mammary glands and ceruminous glands (ear wax).
It is found in virtually all animal body cells 2-How is histamine synthesised within the body? In the present of L-hsitidine decarboxylase, Histamine is synthesised from the decarboxylation of the amino acid histidine. 3- Provide a brief outline of the therapeutic applications of H1, H2 and H3 receptor antagonists. H1-receptor antagonists are usually first-line treatment given for seasonal allergic rhinitis H2 antagonists in attenuating gastric acid secretion have aided many patients with GI disorders. H3 antangoinist can be aided for the treatment of sleep−wake cycle and in memory formation and alertness.
They discovered about 1000 genes which are related to olfactory receptors and gained understanding of how the olfactory system works. Highly specific olfactory receptor cell receptors in the nasal passageways detect an odor and send a nerve impulse to the olfactory center of the brain. The olfactory center then processes this signal and sends the information to other parts of the brain creating a memorable pattern. These recognizable odor patterns, we have about 10,000, stimulate the brain to respond in predictable ways (Nobelprize.org, 2004). By intentionally use of aromatic oils, we can alter emotional states, decrease pain, and treat skin