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The periodic congestion and decongestion of the nasal venous sinuses and an alternation of airflow from one side of the nose to the other are known in literature as “nasal cycle”. It is established that nasal cycle during 24-hours registration contains from 4 to 8 time full periods, length of which varies from 0.80 h to 5.75 h. The mean length of all full periods is 2.80 ± 0.17 h. The mean length of full periods of left nostril is 3.07 h and the mean length of periods of right nostril is 2.43 h. The result suggests that there is any asymmetry in length of periods of airflow trough left and right nostrils about 40 min. The longer periods of left nostril can be connected with higher metabolic and functional activity of brain and human organism during active work.

The spontaneous cyclical activities due to a nasal congestion and decongestion are known in literature as “nasal cycle”. Mirza et al. [

In conection with this we try to characterize nasal cycle during 24-hour registration, using more parameters on the time.

The temperature difference between the inspired and expired air of each nostril was detected by two thermistors inserting in face mask. Signal of thermistors multiplies by electronic amplifier and registers by XY-recorder. The same method was used for investigation of nasal cycle during night sleep [

Subjects were ten right-handed, healthy males (doctors), non-smoking, non-obese, non-snoring. The subjects aged-N1: 18 years, N2: 20 years, N3: 21 years, N4: 25 years, N5: 29 years, N6: 31 years, N7: 38 years, N8: 40 years, N9: 42 years and N10: 45 years. The subjects did not have a history of chronic rhinitis, none were on medications. Registration of nasal cycle was made from 7.0 h in the morning till 7.0 h of other day (morning). The assistants (general practitioner, physician, neurologist or otolaryngologist) catered apparatus and observed subjects. During the 24 hours record daily regime of subjects were the same: wake up and toilet at 6^{30} - 7 h, beginning of record -7^{00} h, breakfast 7^{30} - 8^{00} h, study 8^{00} - 13^{0}^{0} h, lunch and break (without sleep) 13^{00} - 15^{00} h, study 15^{00} - 18^{00} h, dinner and rest 18^{00} - 22^{30} h, toilet for sleep 22^{30} - 23^{00} h, sleep 23^{00} - 7^{00} h (next morning).

On ^{00} h to 7^{45} h, from 11^{20} h to 14^{00} h, from 16^{20} h to 18^{40} h, from 24^{15} h to 2^{40} h and from 5^{15} h to 7^{00} h the airflow trough right nostril is higher versus airflow trough left nostril (i.e. right nostril dominated towards left nostril). From 7^{45} h to 11^{20} h, from 14^{00} h to 16^{20} h, from 18^{40} h to 0^{15} h and from 2^{40} h to 5^{15} h the airflow trough left nostril is higher versus airflow trough right nostril (i.e. left nostril dominated towards right nostril). Cyclic change of airflow of nostrils became simultaneously.

Relation of times, when dominated right nostril toward left and reverse (each nostril have higher airflow related to other) in this case was ranged as-Right: Left: Right: Left: Right: Left: Right: Left: Right = 0^{45'} h: 3^{35'} h: 2^{40'} h: 2^{20'} h: 2^{10'} h: 5^{25'} h: 2^{25'} h: 2^{25'} h: 1^{45'} h.

On

The 10 records of the nasal cycle/one record of each subject/were analyzed. From the record was found 85 time periods of the nasal cycle. Insufficient periods at the beginning and at the end of each record are excluded. We analyzed just full 65 periods and present histogram of distribution of these periods according to their duration and number of observation. It is used a computing program for Windows “Statistica”, for calculations.

(a) The record of nasal cycle of left and right nostril during 24 h registration (from 7.0 h to 7.0 h of 45 years old man). The nasal cycle is of type: Right: Left: Right: Left: Right: Left: Right: Left: Right = 0^{45'} h: 3^{35'} h: 2^{40'} h: 2^{20'} h: 2^{10'} h: 5^{25'} h: 2^{25'} h: 2^{25'} h: 1^{45'} h. The nasal cycle contained 8 time periods. The nostril with higher airflow has high amplitude of record. The nostril with low airflow has low amplitude of record. Temperature of room-space is 25˚C. The velocity of paper is 20 mm/h. Sensibility of scheme 4 mV/1˚C. (b) Scheme of distribution of periods of the right and left nostril. With-line are marked the duration of time-periods in the nasal cycle on record

The lenght of full periods of the right and left nostrils varies from 0.80 h to 5.75 h. The mean length of all full 65 periods of the nostrils was T = 2.80 ± 0.17 h. The mean length of periods of left nostril was 3.07 h and the mean length of periods of right nostril was 2.43 h (see

Mean values, standard errors of mean (SEM), 95% confidence limits and standard deviation (SD) of all periods of left and right nostrils on histogram are given in

Registrated for 24 h nasal cycles contained time periods with lenght 0.80 h - 5.75 hours. The periods with similar lenght from 1 h to 5 h are more often measured in the studies of other authors during day and night [

The sum duration of all periods of left nostril during 24-hours registration is about 10% longer than sum duration of right nostril. For example: the mean length of all periods of left nostril (3.07 h) is longer than mean lenght of all periods of right nostril (2.43 h) with 0.64 h (38.4 min). But, the numbers of periods of two nostrils are nearly similar. The left nostril has 30 periods and right nostril has 33 periods. The result suggests, there is

. Means values, SEM, 95% confidence limits and SD of nostril’s periods

Nostrils | Means | S.E.M | 95% confidence limits | S.D. |
---|---|---|---|---|

Left and right | 2.80 h | 0.17 h | 2.45 - 3.14 | 1.38 |

Left nostril | 3.07 h | 0.26 h | 2.55 - 3.59 | 1.45 |

Right nostril | 2.43 h | 0.21 h | 2.00 - 2.87 | 1.23 |

Histogram of number of observation and distribution of periods of the nasal cycle during 24 h registration (n = 65 periods)

any asymmetry in length of periods of the left and the right nostrils. In earlier investigations of Atanasov [

It is known, that in left hemisphere are located humane speech functions, understanding of acoustic and visual information, control of the right hand and others. Werntz et al. [