One of the best-studied responses of cognitive evoked potentials is a so-called “P300”, the late positive wave complex that occurs about 300-500 ms after the stimulus. It is obtained when the subject’s attention is focused on a signal that is rare, especially if the signal has a motivational or emotional meaning. In the study of P300 potential, we followed the variations of potential amplitude and latency, so the objective was to examine whether there is a difference in Fz and Cz amplitudes of auditory induced cognitive evoked P300 potential depending on the performance of oddball tasks, both in male and female subjects. The study included 60 subjects (30 female respondents and 30 male respondents). P300 potential is induced by the auditory "oddball" paradigm with 80% of non-target and 20% of target stimuli that are presented to the patient through headphones. The target tones are high tones of 2000 Hz. The standard, 1000 Hz tones the respondent should ignore but when he hears the target tones the respondent should press the button on the special handle. The value of Fz and Cz amplitudes both in male and female subjects obtained in the classical "oddball" paradigm when the subject reacted to the signal by pressing the key with the dominant (right) arm were statistically significantly lower (p>0,05) than the values of Fz and Cz amplitudes obtained when the key was pressed by the non-dominant hand. Based on this experiment it can be concluded that both in male and female subjects the performance of oddball tasks does not affect the amplitude of P300 cognitive evoked potentials.

Event-related potential which represents a large positive wave which varies in amplitude and depends on subject's capability as well as on stimulus modality on which subject needs to react and appears around 300 ms after stimulation is called event related potential P300. In 1965. Sutton and the assistants were the first to suggest division of evocated potentials, according to the stimulus that provoke them, on "exogenous" (under the influence of exogenous stimulus) and "endogenous" or "cognitive" provoked by endogenous stimulus, which depends on the state of consciousness (vigilance), attention, concentration and especially, the type of the task a subject needs to perform during the recording. One of the most studied responses of the event-related potentials is so called "P300", the late positive wave complex which appears around 300 500ms after the stimulus. It is gained when the subjects' attention is focused on the signal which rarely appears, especially if the signal has some emotional or motivational meaning. The aim of this work was to determine whether there was a difference in latency and amplitude of the event related potential P300 when the button is pushed with dominant hand compared with nondominant hand in both males and females. The experiment included 30 subjects (15 males and 15 females). P300 potential was provoked with the auditive "oddball" paradigm. Event-related potencial P300 is recorded with 10-20 system. Cz electrode is set in the middle of nazion-inion line, while Fz electrode is set on the third of nazion-inion line above frontal lobe. In classical "oddball" paradigm, when a subject reacted on the signal by pushing the button with dominant hand, the value of Fz end Cz latency was significantly shorter in comparison to the values of Fz end Cz latency gained by pushing the button with non-dominant hand (left hand) in males, while such differences were not found in females. 

Systematic and programmed physical exercise, called training, play a significant role in human health and ability improvement. A moderate physical exercise is considered as a very efficient method of increasing general physical ability and reaching the top results in sport, and simultaneously contributes to health quality of persons having sedentary professions. In active sportspersons, ability of cardiovascular, respiratory and bone-muscle systems are determined by training quality itself. Sportspersons show characteristically better adaptability of neurohumoral system to effort, as well as a higher activity of intracellular enzyme systems. Well-dosed physical exercise has an exceptional influence on human health, above all by regulating cholesterol blood level and electrolyte level of serum, whose minimal change can directly affect human health. This study was aimed to establish quantity and quality of organism response to physical exercise, in regard to level of daily training, by determining lipid fractions level in serum and electrolyte composition of serum. The study involved 50 healthy men in age between 20 and 25, divided into two groups. The first group was composed by physically untrained men, chosen by the random sample method. The other group of subjects was composed by 35 active sportsmen, chosen by direct selection for the best-trained ones among them. In order to reach a submaximal exertion, we used Astrand's test of submaximal exertion on the bicycle-ergometer. Blood samples were taken immediately before and after testing. The following parameters were determined in blood serum: high-density lipoproteins (HDL), low-density lipoproteins (LDL), triglyceride + + 2+ 2+ - content, as well as concentration of sodium (Na ), potassium (K ), calcium (Ca ), magnesium (Mg ) and chlorine (Cl) ions. On the base of our research we concluded that physical exercise of submaximal intensity did not lead to any quantitative and qualitative change of lipid fractions in blood serum of untrained persons. Physically inactive persons had higher serum concentrations of triglycerides and total cholesterol in regard to the investigated sportsmen. At the same time, sportsmen showed a higher HDL content of serum. Physical exertion in sportsmen led to a significant rise of triglycerides and highdensity lipoproteins content of serum, and the levels of total cholesterol and low-density lipoproteins did not changed + ++ significantly. Physical exertion of submaximal intensity in both studied groups caused a significant increase of Na , Ca and ++ + - Mg ion concentration, while concentration of K and Cl ions did not changed significantly. Numerous clinical studies showed that moderate aerobe exercise amplifies endothelial function and reduces cardiovascular risk

Glucagon is polypeptide hormone derived from pancreas which in addition to its metabolic actions has also certain cardiovascular stimulatory effects. We've explored the effects of glucagon on hemodynamic variables (mean arterial pressure, heart rate and central venous pressure) and on catecholamine level and the electrolite level in the kanine sera. It was estimated that glucagon expressed the positive chronotropic effect and significantly lowers the central venous pressure while inconsiderably inceases mean arterial blood pressure. It also leads to transient (short-lasting) hipokaliemia and nonsignificant hipocalcemia. As the result of the action of the glucagone, the serum adrenaline concentrations were significantly increased while the serum noradrenaline concentratios were significantly decreased

Scientific research of effects of glucagon on the cardiovascular system have shown that glucagon has some
cardiostimulatory potential. The very interesting fact is that glucagon shows its cardiostimulatory effects by activating its
own, higly specific glucagonic receptors. That is way we wanted to research not only the effects of glucagon on the C.V.S.
but also its effects during the depression of the C.V.S. with high dosses of beta blocators (presolol) expecting a good
hemodinamic response. The experiment has been performed on two groups of 6 dogs. The first group of animal was treated
with i.v. bolus injections of glucagon and other group with presolol (15 mg/kg b.w.) i.v., and after that with i.v. bolus
injection of glucagon. Hemodinamic variables (mean arterial pressure, central venal pressure and hearth frequency) were
registred at the 1-st, 2-nd, 3-rd, 10-th, 20-th, 30-th and 40-th minute. The hearth frequency was registred by continous
monitoring, mean arterial pressure was registred with cateter in the arterial femoralis, while the central venal pressure was
registred over central venal cateter in v. femoralis. After the i.v. bolus injection glukagon shows higly positive effects,
followed by short-term increase of the mean arterial pressure, while the c.v.p. considerably falls. During the administration
of presolol the hearth frequency and mean arterial pressure fall considerably and progressively, while the c.v.p. rises
considerably. Glucagon, in conditions of c.v.s. depresion by high doses of presolol (15 mg /kg b.w.) considerably increases
hearth frequency and mean arterial pressure, while the c.v.p. falls considerably.