Biomedical subjects

D Venkatesh

Publications and source records attributed to D Venkatesh.

3 recordsLinked to original sources

PubMed2002

Impact of psychological stress, gender and colour on visual response latency.

The measure of visual reaction time has been used to evaluate the processing speed of Central Nervous System and the co-ordination between the sensory and motor systems. As the reaction time is influenced by different factors, the impact of psychological stress, gender effect and the colour of objects in modulating the reaction time have been investigated in this study. 32 male and 38 female medical students in the age group of 18-21 yrs participated as subjects. It was observed that a) the males had a visual reaction time lesser than their female counterparts b) response latency for green colour was lesser than that for red in both the males and the female subjects and c) psychological stress resulted in a significant decline in the reaction time to green colour in males. The longer reaction time in females could be due to the effect of female sex hormones, which reduced the velocity of nerve impulse and increased the synaptic delay. Green colour evoked a faster response due to its stronger stimulation on the visual receptors.

Adolescent↗

PubMed2001

Predator induced stress and its analgesic potential on estrous and anestrus albino rats.

It has been established that physical stress induces antinociceptive effect. In the present study efforts were made to investigate the role of chronic intermittent psychological stress in the induction of the analgesic effect and the probable role of estrous cycle in modulating the antinociceptive response. Albino rats in regular estrous cycle (n = 15) and those in anestrus (n = 15) were exposed to psychological stress for a period of 20 min each day for 12 consecutive days. The predator (domestic cat) was used to induce the psychological stress. At the end of each session tail flick response time to heat was recorded as a measure of pain perception. It was observed that female estrous rats had a low pain threshold in the beginning but its tolerance increased gradually reaching a peak by 6th to 7th day and returned to control level by 11th day. The anestrus female had higher pain threshold at the beginning and showed a gradual decline to reach the control level as estrous females by 12th day. These results suggest that the ovarian hormones and the corticosterone may modulate the impact of stressor on endogenous pain inhibition and other stress responsive systems.

Analgesia↗

PubMedDate not supplied

Cardio-vascular changes during graded exercise.

In the present study cardio-vascular adaptation to graded exercise was studied in untrained male medical students. The subjects were given two grades of exercise each lasting for about five minutes with a rest of fifteen minutes in between on a mechanically braked bicycle ergometer. There was a statistically significant rise in the heart rate during both the exercise sessions. This rise was persistent even after fifteen minutes of rest following the second session. The systolic blood pressure also showed a statistically significant rise in both the sessions. However, the diastolic blood pressure showed a significant drop in the second exercise session. Both these changes could possibly be attributed to sustained release of epinephrine.

Adaptation, Physiological↗