Morphohistometric evaluation of the embryological development of the heart in chicks

Parameter	Incubation day 10	Incubation day 13	Incubation day 16	Incubation day 21
Embryo weight (g)	3.11 ± 0.21^a	8.91 ± 0.46^b	22.74 ± 2.72^c	41.18 ± 2.26^d
Heart weight (g)	0.021 ± 0.002^a	0.071 ± 0.007^b	0.182 ± 0.031^c	0.237 ± 0.062^d
Relative organ weight (g)	0.686 ± 0.038^a	0.793 ± 0.058^b	0.804 ± 0.152^b	0.577 ± 0.151^a
Heart volume (mm³)	0.371 ± 0.05^a	1.279 ± 0.11^b	1.922 ± 0.43^c	3.239 ± 0.57^d

1a, b, c and d –different superscript letters in the same row represent statistically significant differences (p < 0.001)

Table 2.

Chick embryo heart diameters at different periods (Mean±SD)

Diameter	Incubation day 10	Incubation day 13	Incubation day 16	Incubation day 21
Cranio-caudal (mm)	4.595 ± 0.411^a	7.158 ± 0.369^b	9.375 ± 0.768^c	10.700 ± 0.769^d
Dorso-ventral (mm)	2.662 ± 0.300^a	3.753 ± 0.209^b	5.607 ± 0.539^c	6.007 ± 0.479^c
Medio-lateral (mm)	3.507 ± 0.167^a	4.658 ± 0.291^b	6.510 ± 0.268^c	7.513 ± 0.785^d

1a, b, c and d –different superscript letters in the same row represent statistically significant differences (p < 0.001)

Morphometric measurement of the ventricular wall of heart. RVW – right ventricular wall; RVC – right ventricular cavity; LVW – left ventricular wall; LVC – left ventricular cavity. Crossmon’s trichrome staining. Scale bar – 1 mm

Morphometric measurement of sections of a chick embryo aorta. A – aortic wall thickness; B – aortic diameter; C – aortic lumen diameter; D – aortic lumen area

Application of the point counting grid for chick embryo heart sections

Table 3.

Morphometric measurements of chick embryo heart walls at different periods (Mean±SD)

Parameter (thickness unless stated)	Incubation day 10	Incubation day 13	Incubation day 16	Incubation day 21
Left atrial wall (μm)	8.87 ± 0.88^a	12.67 ± 2.08^ab	15.75 ± 5.25^b	16.40 ± 2.13^b
Right atrial wall (μm)	11.47 ± 3.87	13.50 ± 2.80	13.45 ± 2.35	15.53 ± 4.97
Left/right atrium ratio	0.89 ± 0.44	0.95 ± 0.084	1.14 ± 0.18	1.16 ± 0.43
Left ventricular wall (μm)	60.53 ± 17.08^a	98.56 ± 13.83^b	115.22 ± 21.58^b	156.28 ± 26.07^c
Right ventricular wall (μm)	52.73 ± 6.32^a	79.72 ± 12.68^a	89.06 ± 30.19^a	109.83 ± 30.41^b
Left/right ventricle ratio	1.15 ± 0.31	1.22 ± 0.39	1.47 ± 0.35	1.48 ± 0.37
Interatrial septum (μm)	6.27 ± 1.79^a	6.67 ± 1.25^a	16.78 ± 6.78^b	16.53 ± 5.09^b
Interventricular septum (μm)	69.07 ± 8.13^a	87.28 ± 20.13^a	118.83 ± 15.52^b	139.50 ± 15.74^b

1a, b and c –different letters in the same row represent statistically significant differences (p < 0.001)

Table 4.

Chick embryo heart muscle layer thickness in the ventricular wall at different periods (Mean±SD)

Layer	Incubation day 10	Incubation day 13	Incubation day 16	Incubation day 21
Left epicardium (μm)	3.90 ± 0.33	5.49 ± 0.57	7.55 ± 1.16	14.24 ± 0.68
Right epicardium (μm)	5.01 ± 0.63	8.08 ± 1.46	8.42 ± 1.28	26.73 ± 2.48
Left myocardium (μm)	36.29 ± 5.14	52.26 ± 2.82	71.31 ± 7.13	73.05 ± 2.51
Right myocardium (μm)	38.78 ± 3.36	57.49 ± 3.18	62.53 ± 3.07	66.76 ± 2.71
Left endocardium (μm)	3.39 ± 0.24	4.73 ± 0.45	7.06 ± 0.97	7.48 ± 0.73
Right endocardium (μm)	4.29 ± 0.46	6.63 ± 0.15	7.40 ± 0.66	10.13 ± 0.56

Table 5.

Morphometric measurements of the chick embryo aorta at different periods (Mean±SD)

Parameter	Incubation day 10	Incubation day 13	Incubation day 16	Incubation day 21
Aortic wall thickness (μm)	15.13 ± 1.90^a	20.28 ± 2.27^b	29.26 ± 4.22^c	30.35 ± 3.12^c
Aortic diameter (μm)	52.29 ± 5.34^a	71.22 ± 4.31^b	107.84 ± 10.83^c	110.64 ± 11.71^c
Aortic lumen area (μm²)	342.65 ± 14.12^a	729.82 ± 26.53^b	1864.95 ± 88.15^c	1912.57 ± 75.34^c
Aortic lumen diameter (μm)	21.23 ± 1.37^a	31.54 ± 3.06^a	77.88 ± 11.87^b	70.35 ± 8.47^b

1a, b and c –different superscript letters in the same row represent statistically significant differences (p < 0.001)

Coefficients of error in chick embryonic heart volumes

Histological development of the heart according to different periods. A. 10^th day. B. 13^th day. C.16^th day. D. 21^st day. C – Collateral; Di – Intercalary disc; En – Endocardium; Ep – Epicardium; M – Mesothelium; Myo – Myocardium; Pf – Purkinje fibers; T – Trabecula; RVL – right ventricular lumen; → – cardiomyocyte nucleus. Crossmon’s trichrome staining. Scale bars = 100 μm

References

Authors

Metrics

Articles in this issue

DOI: https://doi.org/10.2478/jvetres-2026-0042 | Journal eISSN: 2450-8608 (formerly 2300-3235)

Journal RSS Feed

Language: English

Submitted on: Jan 19, 2026

Accepted on: Jul 22, 2026

Published on: Jul 27, 2026

Published by: National Veterinary Research Institute in Pulawy

In partnership with: Paradigm Publishing Services

Keywords:

Cavalieri method,

chick embryo,

developmental embryology,

heart

Related subjects:

Life sciences,

Molecular biology,

Microbiology and virology,

Life sciences, other,

Medicine,

Veterinary medicine

© 2026 Muhammet Lütfi Selçuk, Fatma Kayıkcı Hekim, published by National Veterinary Research Institute in Pulawy
This work is licensed under the Creative Commons Attribution 4.0 License.

AHEAD OF PRINT

Morphohistometric evaluation of the embryological development of the heart in chicks

Figures & Tables

Table 1.

Table 2.

Fig. 1.

Fig. 2.

Fig. 3.

Table 3.

Table 4.

Table 5.

Fig. 4.

Fig. 5.

Paradigm

My account