engleski

Some histofunctional observations in the diaphragm of fallow deer (Dama Dama) from the National Park Brijuni (Croatia)

Samples of the costal and both crura of the lumbar part of diaphragm in 11 fallow deer (Dama Dama) of both sexes 1-3 years old from the National Park Brijuni (Croatia) were frozen in liquid nitrogen, cut into 10u thick slide, stained with hematoxin and eosine and pictured under 50x microscopic magnification. On so obtained photographs the diameter of 4, 138 muscle fibers was measured. Using distribution frequency of the muscle fiber diameter with the step of 5 um, muscle fibers were classified in the groups of the same diameter. The diameters were calculated and presented graphically to determine participation of the fibers in the function of diaphragm, with respect to their size and surface, and in the surface. Costal part and both crura comprised muscle fibers different in diameter, ranging from 10-60 um (costal part), 10-65 um (left crus) and 10-70 um (right crus). All three phrenic parts contined less fibers of small diameter of up to 20 um (15.01%, 10.67% and 12, 84%), slightly more fibers of the diameter over 45 um (23.03%, 18, 37% and 15, 17%), and mostly medium-sized diameter fibers, between 20-45 um (62.50%, 70, 96% and 71.99%). Distribution frequency showed that the diaphragm contained three morphofunctional units (MFU) os small diameter, with 10-15% of all muscle fibers engaged in steady breathing. These fibers covered 3.42%, 0.82% and 3.14% of the muscle surface respectively. During heavy breathing the aditional 5 MFU of medium-diameter fibers with 62-71% of all fibers were gradually activated. These MFU covered 74.05%, 85.15% and 83.23% of the muscle surface respectively. During very labored breathing and non-respiration the last 3 MFU in the costal part, 4 MFU in the left crus and 5 MFU in the right crus of the fibers largest in diameter with 15-23% of all fibers were activated. These fibers covered 22.52%, 15.03% and 13.63% of the muscle surface respectively. Contrary to horses, cattle, lambs and pigs in which steady or labored breathing engages either costal or lumbar part of diaphragm, in fallow deer from the Brijuni biotope, these types of breathing and non-respiration engage both diaphragmatic parts simultaneously.

diaphragma; histofunctional; fallow deer

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