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Home / Equine Research Bank / Anat Rec (Hoboken) / Morphological and morphometric characterization of the aorta...
Anatomical record (Hoboken, N.J. : 2007)2025; doi: 10.1002/ar.70026

Morphological and morphometric characterization of the aorta of Brazilian horses (Equus ferus caballus, Linnaeus-1758): Comparative analysis of the aortic bulb and ascending aorta.

Abstract: We examined 52 horse aortas to characterize the morphological aspects of the aortic bulb wall and the ascending aorta. The morphometric data were analyzed using ImageJ®-Fiji 1.5 software. The Tunica intima was composed of endotheliocytes with scarce cytoplasm and ellipsoid nuclei, supported by a collagenous subendothelial stratum. The Tunica media was composed entirely of fascicles of vascular smooth muscle cells interspersed with bundles of collagen fibers and elastic lamellae, characterizing the aortic medial lamellar unit. The Tunica adventitia consisted of two distinct sub-layers: the external lamina, which contained the specific vascular-nervous plexus, and the internal lamina, which was composed of dense, unformed connective tissue. In absolute values, the total thickness of the aortic wall, as well as the thickness of the Tunica media, was significantly less in the aortic bulb than in the ascending aorta. The fibro molecular content of both segments was also analyzed. Thus, 19.1% of the wall in the aortic bulb was composed of vascular smooth muscle cells, 13.9% of elastin, 25.5% of collagen I, and the content of collagen III was 15.6%. The wall of the ascending aorta contained 17.5% vascular smooth muscle cells, 13.8% elastin, 23.5% collagen I, and 15.1% collagen III. The increase in the thickness of the Tunica media determined the increase in the total wall thickness of the aortic bulb compared to the ascending aorta. Furthermore, the increase in wall thickness observed between the segments analyzed did not affect the relative amount of fibro-cellular elements in each segment.
© 2025 American Association for Anatomy.
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Publication Date: 2025-07-31 PubMed ID: 40740156DOI: 10.1002/ar.70026Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research examines the shape and measurement of the aorta in 52 Brazilian horses and compares the structure of the aortic bulb and the ascending aorta.

Morphological Characterization

  • The aorta is the main artery carrying blood away from the heart. In this study, specific attention is given to the aortic bulb (the start of the aorta) and the ascending aorta (the part following the bulb).
  • The aorta is composed of three layers: the Tunica intima, the Tunica media, and the Tunica adventitia. Each layer has different components and serves distinct functions in the cardiovascular system.
  • The innermost layer, the Tunica intima, is made up of endotheliocytes with scarce cytoplasm and ellipsoid nuclei, supported by a collagenous subendothelial layer.
  • The middle layer, the Tunica media, is entirely composed of vascular smooth muscle cells interspersed with collagen fibers and elastic lamellae, forming what is referred to as the aortic medial lamellar unit. The muscle cells help the aorta contract and pump blood.
  • The Tunica adventitia, the outermost layer, features two unique sub-layers: a vascularized external lamina containing nerves and an internal lamina made of dense, non-specific connective tissue. The adventitia provides structural support to the aorta.

Morphometric Characterization

  • ImageJ®-Fiji 1.5 software was used to analyze morphometric data, helping to detail the structure and size of the aorta.
  • The researchers found that the total thickness of the aortic wall and the thickness of the Tunica media were significantly less in the aortic bulb than in the ascending aorta.
  • The study also examined the content of various fibro-molecular components in these segments. In the aortic bulb, vascular smooth muscle cells made up 19.1%, elastin 13.9%, collagen I 25.5%, and collagen III 15.6%. In the ascending aorta, it contained 17.5% vascular smooth muscle cells, 13.8% elastin, 23.5% collagen I, and 15.1% collagen III.
  • It was noted that an increase in thickness of the Tunica media resulted in an increase in overall wall thickness in the aortic bulb compared to the ascending aorta. However, this rise did not influence the relative proportion of the fibro-cellular elements in both segments.

Cite This Article

APA
Böck MJ, Fernandez TJ, Pereira VP, da Veiga ML, de Mello Bertoncheli Dos Santos C, de Morais-Pinto L. (2025). Morphological and morphometric characterization of the aorta of Brazilian horses (Equus ferus caballus, Linnaeus-1758): Comparative analysis of the aortic bulb and ascending aorta. Anat Rec (Hoboken). https://doi.org/10.1002/ar.70026

Publication

Anatomical record (Hoboken, N.J. : 2007)
ISSN: 1932-8494
NlmUniqueID: 101292775
Country: United States
Language: English

Researcher Affiliations

Böck, Marcelo José
  • Laboratório de Design Anatômico-LabDA, Departamento de Morfologia, Universidade Federal de Santa Maria, Santa Maria, Brazil.
Fernandez, Thiago José
  • Programa de Pós-Graduação em Anatomia dos Animais Domésticos e Silvestres da Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Sao Paulo, Brazil.
Pereira, Vitor Pires
  • Laboratório de Design Anatômico-LabDA, Departamento de Morfologia, Universidade Federal de Santa Maria, Santa Maria, Brazil.
da Veiga, Marcelo Leite
  • Laboratório de Morfofisiologia Experimental-LABITEX, Departamento de Morfologia, Universidade Federal de Santa Maria, Santa Maria, Brazil.
de Mello Bertoncheli Dos Santos, Claudia
  • Laboratório de Anatomia Patológica-Hospital Universitário, Universidade Federal de Santa Maria, Santa Maria, Brazil.
de Morais-Pinto, Luciano
  • Laboratório de Design Anatômico-LabDA, Departamento de Morfologia, Universidade Federal de Santa Maria, Santa Maria, Brazil.

Grant Funding

  • Termo de Outorga: 21/2551-0002248-5 / Fundau00e7u00e3o de Amparo u00e0 Pesquisa do Estado do Rio Grande do Sul
  • Coordenau00e7u00e3o de Aperfeiu00e7oamento de Pessoal de Nu00edvel Superior (CAPES)

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