MOJ eISSN: 2471-139X MOJAP

Anatomy & Physiology
Research Article
Volume 1 Issue 3

A sex related changes of the one humped camel (Camelusdromedarius) thyroid gland: (a histomorphological study)

Bello A,1 Onyeanusi BI,2 Sonfada ML,1 Adeyanju JB,3 Umaru MA,4 Onu JE1
1Department of Veterinary Anatomy, Usmanu Danfodiyo University, Nigeria
2Department of Veterinary Anatomy, Ahmadu Bello University Zaria, Nigeria
3Department of Veterinary Surgery and Radiology, Usmanu Danfodiyo University, Nigeria
4Department of Theriogenology and Animal production, Usmanu Danfodiyo University, Nigeria
Received: October 08, 2015 | Published: October 30, 2015

Correspondence: Bello A, Department of Veterinary Anatomy, Usmanu Danfodiyo University, Nigeria, Tel +234(0)8039687589, Email

Citation: Bello A, Onyeanusi BI, Sonfada ML, et al. A sex related changes of the one humped camel (Camelusdromedarius) thyroid gland: (a histomorphological study). MOJ Anat Physiol. 2015;1(3):68‒70. DOI: 10.15406/mojap.2015.01.00014

Abstract

A histomorphological study of the thyroid glands of 15 healthy camels (Camelus dromedarius) of different sex group A (Males) and group B (Females), were investigated for gross and microscopic anatomy. Gross studies revealed that thyroid glands were located in between the third ring of trachea and the laryngopharynx portion of the pharynx and had two lobes, connected by an isthmus. They appeared to be reddish brown in colour. The values of weight, length, width and diameter of thyroid glands were show no significant difference between the groups (P>0.05). Histological observation revealed that the thyroid gland consisted of a connective tissue capsule and trabeculated were found extending from the capsule into the substance of the gland, which divided it into lobules.1 Each lobule consisted of two sized follicles in variable numbers, the large and small. The large follicles were lined by low cuboidal epithelium, while the small follicles were lined by high cuboidal to columnar epithelium. The follicles had colloid material in their lumen, probably an apocrine secretion from the lining epithelial cells. There was no evidence of Para follicular or C-cells in thyroid glands of camel.

Keywords: camel, thyroid gland, gross, histomorphology

Introduction

The thyroid is an endocrine gland which secretes thyroglobulin, triiodothyronine and thyroxin hormones.2,3 Thyroxin plays an important role in metabolism of the animal body. Thyroid gland consists of follicles lined by follicular cells. The intermolecular space has been reported to be filled with connective tissue.4,5 The most outstanding feature of the vertebrate thyroid gland is its ability to concentrate large amount of iodine for the synthesis of thyroxin.6 The normal anatomy and physiology of dromedarian camel is least understood when compared to Llama, Guanaco, Cattle, Sheep, Goat and Pig.5 The description of dromedarian camel is usually made as if it is identical with Llama specie.5,7 Though, they are seasonal breeders5,8 that are closely related anatomically to the South American Camelids5,6,9,10 little is known on the anatomy and physiology of the thyroid gland. The present study was conducted to investigate the normal microscopic anatomy of thyroid gland of one humped camel (Camelus dromedarius) with the aim of understand the teaching of anatomy and physiology of the gland of the dromedarian Camel in the world.

Materials and methods

The study was carried out on 15 normal Adult one-humped camel collected from the metropolitan abattoir, Sokoto in winter season, using standard animal ethics approved by the government. The collected samples were then taken to the Veterinary Anatomy laboratory of Usmanu Danfodiyo University; where the gross and biometric values were determined.11 1cm2 thick of sample from each segment was collected and fixed in 10% formalin solution. After fixation was achieved, the tissue sample was processed for paraffin blocks preparation. The sections of 5µm were subjected to haematoxylin and eosin for routine morphology. The standard sections were examined under light microscope and micrographs taken using Sony digital camera (x5) with 12.1 mega pixel.

Results and discussion

Gross observations

Gross studies of thyroid gland of camel revealed that the gland was located in between the third ring of trachea and the laryngopharynx portion of the pharynx and consisted of two lobes. An isthmus connected these lobes to each other and reddish brown in colour. This finding is similar to other large animals like cattle and buffaloes11 i.e., with the first ring of trachea and consisted of two lobes on both side and an isthmus connecting these lobes. In camel, the colour of the gland is in concordance with the findings of Schwartz and Dioli.12 The values of weight, length, width and diameter in camels of different sex groups viz male and female are presented in Table 1. The mean weight was 43.90 and 48.08g in two groups respectively, which was slightly lower than previously reported value of 52.7gm in camel.13 It has been reported that in summer the size of the gland increases.14 The mean diameters recorded were 0.97 and 1.05cm which fell in the range of 0.5 to 1.5cm in adult camels.12 The mean length recorded was 5.36 and 6.36cm, and is in agreement to 3 to 8cm reported by Abdel-Wahab and Hamza13 in camel. Similarly, the width of gland recorded was 3.35 and 3.53cm and is in range of 1 to 4cm reported earlier in this species.12 The statistical analysis revealed non-significant difference in various parameters between the two sex groups. However, the values of all the parameters were relatively higher in male camels compared with female group.

Female

Male

Weight (g)

45.70 ± 0.35a

50.55 ± 0.26b

Length (cm)

5.36 ± 0.46a

6.36 ± 0.33b

Width (cm)

3.35 ± 0.29a

3.53 ± 0.21b

Diameter (cm)

0.97 ± 0.13a

1.05 ± 0.14b

Table 1 values (Mean ± SD) of different parameters in camels of two age groups Parameters

Histological findings

Histologically, the thyroid gland consisted of a connective tissue capsule composed of coarse and fine collagenous fibers with scattered fibroblast and small blood vessels all over the capsule (Figures 1‒3). The trabeculated were seen extending from the capsule into the substance of the gland and dividing it into lobules. Blood vessels were also present in the connective tissue of the trabeculated. Each lobule consisted of aggregation of follicles. Three types of follicles were identified, large (A), medium (B) and small (C) (Figure 4). The large follicles were lined by low cuboidal epithelium having flattened nuclei and were assumed to be inactive cells while the medium follicles were lined by columnar epithelium having oval nuclei. The small follicles were lined by cuboidal epithelium with rounded nuclei, these were active cells. Each follicle was filled with a gel-like material called colloid (Figure 3). The colloid is a storage form of follicular epithelial secretion. There is no evidence of Para follicular or C-cells in thyroid glands of camel. This result shown similar observations as reported previously in camel15,16 i.e. the gland consisted of follicles of variable sizes with smaller lined by low cuboidal to semi squamous epithelium, while the larger ones were lined by high cuboidal to columnar epithelial cells. The parafollicular or C-cells were found missing but has been reported in cattle and buffaloes.17 Similar observations have been recorded by Abdel-Magied et al.15

Figures 1‒3 Thyroid gland consisted of a connective tissue capsule composed of coarse and fine collagenous fibers with scattered fibroblast and small blood vessels all over the capsule.

Figure 4 Aggregation of follicles.

Conclusion

Base on the above findings, it can be concluded that thyroid gland does not vary considerably in weight, length, width and diameter between male and female adult camels.

Acknowledgements

None.

Conflict of interest

Author declares that there is no conflict of interest.

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