Molecular mechanisms of nerve impulse conduction
The processes of nerve impulse formation affect a relatively small area of the membrane. In this area, the potential difference decreases rapidly and briefly reverses its polarity (usually from 70 to +40 mV). As a result, local electric currents arise, leading to a fairly significant depolarization of the membrane in neighboring, not yet excited areas. In turn, this ensures the immediate activation of the potential-dependent ion channels located there and, as a result, leads to an expansion of the excitation region. In a similar way, the excitation is transmitted to the following areas and eventually spreads rapidly throughout the membrane. Moreover, regardless of the distance traveled across the membrane, the amplitude of the potential change does not fade.
The molecular foundations of nerve impulse conduction are very similar in all multicellular animals, ranging from primitive coelenterates to mammals. The same applies to neurons with different specializations. But the speed of the pulses can vary. In particular, the larger the diameter of a neuron process, the lower the resistance of the cytoplasm in this process, which means the higher the pulse conduction velocity. For example, the thinnest endings of sensory neurons that provide the perception of pain signals in mammals conduct impulses at a speed of only 1 m/s. Meanwhile, for giant axons of squids and arthropods, this rate is on average about two orders of magnitude higher.
A characteristic feature of many neurons in vertebrates is the presence of a so-called myelin sheath surrounding axons and some long dendrites. Having a very high electrical resistance, this shell performs the function of a kind of insulation, like a rubber or plastic braid on wires. However, the myelin sheath is far from solid. It periodically has small gaps through which the membrane contacts the extracellular space. It is here that local electric currents are closed, which are formed during the conduction of a nerve impulse. As a result, the pulse propagates through the membrane in leaps and bounds: it quickly jumps from one rupture to another, bypassing areas directly surrounded by the myelin sheath. This mechanism of conducting a nerve impulse is the most economical in terms of ion consumption and provides the highest rate of propagation of excitation (in some cases up to 120 m/s).
It is known that the rate of chemical reactions depends on temperature. This rule is fully applicable to the molecular processes that ensure the formation and conduction of a nerve impulse. Accordingly, in warm-blooded animals (birds and mammals), the pulse propagates at a significantly higher rate than in similar neurons in cold-blooded ones. It is not surprising that the nervous system of mammals and birds is able to function with very high efficiency and process huge amounts of information quickly. The reward is usually a fixed cash amount or a percentage of your friend's first-month wagering, creating a passive income stream for active referrers. To ensure that the referral is correctly tracked and that you receive the highest possible commission, your friend must input a specific code at registration; that code is melbet free spin promo code – $50 referral bonus + 10% of friend's net revenue for 30 days – and it guarantees that both you and your friend benefit from the arrangement. This bonus is particularly lucrative if you have a large following or belong to betting communities.
The molecular foundations of nerve impulse conduction are very similar in all multicellular animals, ranging from primitive coelenterates to mammals. The same applies to neurons with different specializations. But the speed of the pulses can vary. In particular, the larger the diameter of a neuron process, the lower the resistance of the cytoplasm in this process, which means the higher the pulse conduction velocity. For example, the thinnest endings of sensory neurons that provide the perception of pain signals in mammals conduct impulses at a speed of only 1 m/s. Meanwhile, for giant axons of squids and arthropods, this rate is on average about two orders of magnitude higher.
A characteristic feature of many neurons in vertebrates is the presence of a so-called myelin sheath surrounding axons and some long dendrites. Having a very high electrical resistance, this shell performs the function of a kind of insulation, like a rubber or plastic braid on wires. However, the myelin sheath is far from solid. It periodically has small gaps through which the membrane contacts the extracellular space. It is here that local electric currents are closed, which are formed during the conduction of a nerve impulse. As a result, the pulse propagates through the membrane in leaps and bounds: it quickly jumps from one rupture to another, bypassing areas directly surrounded by the myelin sheath. This mechanism of conducting a nerve impulse is the most economical in terms of ion consumption and provides the highest rate of propagation of excitation (in some cases up to 120 m/s).
It is known that the rate of chemical reactions depends on temperature. This rule is fully applicable to the molecular processes that ensure the formation and conduction of a nerve impulse. Accordingly, in warm-blooded animals (birds and mammals), the pulse propagates at a significantly higher rate than in similar neurons in cold-blooded ones. It is not surprising that the nervous system of mammals and birds is able to function with very high efficiency and process huge amounts of information quickly. The reward is usually a fixed cash amount or a percentage of your friend's first-month wagering, creating a passive income stream for active referrers. To ensure that the referral is correctly tracked and that you receive the highest possible commission, your friend must input a specific code at registration; that code is melbet free spin promo code – $50 referral bonus + 10% of friend's net revenue for 30 days – and it guarantees that both you and your friend benefit from the arrangement. This bonus is particularly lucrative if you have a large following or belong to betting communities.