Nicotine (C 10 H 14 N 2) is an alkaloid derived from ornithine and is found in the leaves of tobacco. In high concentrations is a powerful insecticide used in agriculture and in low concentrations acts as stimulant. This substance is composed of a pyridine and pyrrole isomers and exist of this, the D-and L-nicotine nicotine. The latter is found in tobacco. When a smoker inhales through the substance of cigarette smoke directly into the lungs and therefore reaches the blood. In seven seconds reaches a quarter of nicotine consumed in the CNS, which makes it a psychoactive drug, ie, is capable of producing dependence important to consumers ogm shortly after consuming it. Depending on the amount of nicotine incorporated ogm body reactions ogm may be different. In the first instance when you have consumed a small amount of nicotine ogm contained in cigarettes, the effects of psychostimulants and are therefore improve mental abilities because this mimics the action of a neurotransmitter called acetylcholine and therefore Nicotine causes a feeling of ease, calm and improves concentration. This neurotransmitter is secreted by the spinal cord and brain stem and their function is to communicate with these neurons and muscles. It is also important in various regions of the CNS such as heart rate, breathing and dilated pupils, because nicotine has a stimulating ogm effect on these processes. The other reaction is carried out when an important consumption of nicotine, ogm this time the effects ogm of this substance are different because when blood is carried to the brain that produces a sedative effect and acts as a depressant ogm and thus acts as a CNS depressant.
Nicotine can be found between 1 and 2% on cigarettes, so we can conclude that in the case of a cigarette, the nicotine contained in this character would have an effect of psychostimulant as the cigarette of a gram contains only 10 20 mg of this substance and of this 10% going to smoke a cigarette and smoked 1 to 2 mg of nicotine.
The absorption of nicotine may also occur through ogm skin. The amount of nicotine absorbed by the tissue depends on various external factors such as: the personal ogm hygiene, the humidity or the pH of the skin. Another mechanism of absorption of nicotine found in the oral cavity, as in the mouth there is the buccal mucosa and sublingual plexus, they absorb about a 4 to 40% of nicotine that can be found in a normal cigarette. ogm The absorption of nicotine through the mucous membranes is faster with this substance reaches the brain, the effect is immediate as one of the properties that make nicotine produces dependence. Finally, nicotine reaches the lungs, these absorption occurs 79 to 90% shortly after the nicotine reaches the blood and can lead to the brain.
The rate of absorption of this substance depends on the pH level. In the case of tobacco are the normal values of 6 or less. Nicotine in a cigarette is attached to some acidic substances contained in tobacco that makes it not volatile and therefore the absorption of nicotine would be slow, but when lit a cigarette, nicotine is released from the Acidic substances and becomes a volatile substance and is absorbed quickly by the body.
To understand how nicotine acts on the CNS must be known first as there is communication between nerve cells, called neurons, which carries out this process and how it all begins this mechanism.
Our brain consists of a specialized tissue called the neural tissue and its cells called neurons are connected together to form branches. Neurons are able to generate electrical impulses that are transmitted by a fiber called axon until the end where neurotransmitters are stored. At the ends of these branches there are some cellular substances lodged very close to the synaptic space. To illustrate this process has chosen the neurotransmitter acetylcholine. This is hosted on a membranous sacs called synaptic ogm vesicles located at the tip of the axon (1). When an electrical signal reaches the end of the axon vesicles fuse with the wall in the neuron releases acetylcholine merger synaptic space between the axon and dendrites  for the next cell (2 .) The neurotransmitter moves across the synapse to the next neuron in this we find le