A comparative study of oculomotor, trochlear and abducens nerves in Arabian foals.

We investigated the microscopic structure of transverse sections of the oculomotor, trochlear and abducens nerves of Arabian foals using stereological methods. Bilateral nerve pairs from 2-month-old female Arabian foals were analyzed. The tissues were embedded in plastic blocks, then 1 µm thick sections were cut and stained with osmium tetroxide and methylene blue-azure II. Stereology was performed using light microscopy. Morphometry showed that the right and left pairs of nerves were similar. The transverse sectional areas of the oculomotor, trochlear and abducens nerves were 1.93 ± 0.19 mm2, 0.32 ± 0.06 mm2 and 0.70 ± 0.08 mm2, respectively. The oculomotor nerve exhibited a significantly greater number of myelinated axons (16755 ± 1279) and trochlear (2656 ± 494) and the abducens nerves (4468 ± 447). The ratio of the axon diameter to myelinated nerve fiber diameter was 0.58, 0.55 and 0.55 for the oculomotor, trochlear and abducens nerves, respectively. Of the three nerves studied, the abducens nerve exhibited the greatest nerve fiber area, myelin area, nerve and axon diameters, and myelin thickness. The ratio of small myelinated nerve fibers was greatest in the oculomotor nerve.

Tongue and lingual salivary glands of the canary: scanning electron microscopy and histochemical study.

In this study, morphological characteristics of the canary tongue were examined macroscopically and histologically besides using scanning electron microscopy. Furthermore, histochemical features of the lingual salivary glands of the canary were also examined. The results suggest that the tongue of the canary has an equilateral quadrangle shape is sloped towards the apex on its dorsal surface; where its sides are bounded by tall epithelial extensions. Additionally, histological examination showed that salivary glands were only present on the body of the tongue and there were no taste buds. However, the tongue has mechanical sen-sory cell groups in its subepithelial connective tissue. Histochemical examination, demonstrated that the salivary gland epithelial cells contained carbohydrates which were composed of acidic sialo-mucins.

Postnatal osteological development of the hyoid bone in the new zealand white rabbit.

This study augments knowledge of bone growth by observing the development of the hyoid bone in the New Zealand White rabbit. Preserved hyoid bones representing five different age periods, each period including five individuals and the total number of animals being 25, were fixed in 3.5% formaldehyde solution and 95% ethanol, followed by a pure acetone bath. They were then stained with an alcian blue-alizarin red combination. The mode of bone formation was intracartilaginous type ossification. While the basihyoideum and thyrohyoideum were observed to start ossifying first at prenatal stage, indicating that they are the main skeletal structures of the hyoid apparatus, the ceratohyoideum and lingual process began to ossify in the second and third periods. The separately occurring primary ossification centres fused completely among themselves in the fifth period. Because no further ossification centers were observed and the ossified parts continued the development and growth, the research was terminated after 10 weeks of age.

Postnatal osteological development of the cervical vertebrae in the New Zealand White rabbit.

This study used the New Zealand White rabbit to reveal the normal ossification development of the cervical component of the spine. Preserved cervical vertebrae representing five different age periods, each period including five individuals and the total number of animals being 25, were fixed in 3.5% formaldehyde solution and 95% ethanol, followed by a pure acetone bath. The materials were then stained with an alcian blue-alizarin red combination. The ossification centres were identical over time, and the pattern of fusion among them was homogenous and constant in appearance. There were three different primary ossification centres in all the cervical vertebrae except the axis, which showed four primary ossification centres. The dorsally located primary ossification centres later formed the pedicles of the neural arches, while the ventral centres constituted the body of each vertebra. The study was terminated at 10 weeks of age because the ossification centres observed in the cervical vertebrae completed their fusion and no further ossification centres were observed.

Extrinsic cardiac nerve distribution in goitred gazelle (Gazella subgutturosa).

Extrinsic cardiac nerves and their patterns are described based on anatomical dissections of five goitred gazelle. Sympathetic cardiac innervation was mainly provided by the cervicothoracic and thoracic cardiac nerves. No left caudal cervicothoracic nerves, middle cervical cardiac nerves and vertebral cardiac nerves from the vertebral ganglion were observed. Parasympathetic cardiac innervation was supplied by the nerve fibres from the caudal vagal cardiac rami only. No cardiac rami from the cranial vagal cardiac nerves present in small ruminants were observed in this study. The caudal laryngeal and phrenic cardiac nerves also contributed to the cardiac innervation.

A detailed subgross morphometric study on the auditory ossicles of the New Zealand rabbit.

This study was designed to reveal, in detail, the features of the auditory ossicles of the New Zealand rabbit, one of the most frequently used animals in scientific researches. Heads of 10 dead adult New Zealand rabbits of both sexes weighing 2.5 +/- 0.2 kg were used in the study. The auditory ossicles were gently removed from their situs and observed. The auditory ossicles were three small bones: the malleus, the incus and the stapes. The lenticular bone seemed to be the lenticular process, as is in human beings. In general, macroanatomic features of the bones were similar to those reported in the literature. Findings in this study, however, differed greatly, especially in detail. There were statistically significant differences in the morphometric data of the features of the auditory ossicles between the right- and left-hand sides. Data from the right-hand side were significantly higher.