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Histological organization of the right and left atrioventricular valves of the chicken heart and their relationship to the atrioventricular Purkinje ring and the middle bundle branch
- Source :
- The Anatomical record. 235(1)
- Publication Year :
- 1993
-
Abstract
- In the avian heart the right and left atrioventricular (AV) valves not only exhibit their own special anatomical characteristics, but they also are in close proximity to the conduction system. The right AV valve is a single, spiral plane of myocardium, in remarkable contrast to the fibrous structure characteristic of the mammalian tricuspid valve. A ring of Purkinje tissue encircles the avian right AV orifice and connects to the muscular valve. The chicken has no crista supraventricularis, its right AV valve serving that function as well as opening and closing the right AV orifice. The left AV valve consists of three leaflets instead of the two typical of mammalian hearts. Its anterior and posterior leaflets are small; its large aortic (medial) leaflet merges with the bases of both the left and noncoronary cusps of the aortic valve by fibrous tissue, resembling that of the mammalian heart. However, unlike in mammals, there is a slim cylinder of continuous myocardium coursing parallel to this fibrous junction. This unusual arc of myocardium in the chicken serves to complete an entire subaortic ring of myocardium and is thus potentially capable of constricting the outflow tract of the chicken's left ventricle. The middle bundle branch connects with both the muscle arch and the AV Purkinje ring. Thus the myocardium in or near both AV valves (and the left ventricular outflow tract) in the chicken heart is so arranged that it may receive direct early activation from the conduction system. ©1993 Wiley-Liss, Inc.
- Subjects :
- Aortic valve
medicine.medical_specialty
Bundle of His
Purkinje fibers
Purkinje Fibers
Internal medicine
medicine
Ventricular outflow tract
Animals
cardiovascular diseases
Heart valve
Atrioventricular valve
Tricuspid valve
business.industry
Heart
Anatomy
Agricultural and Biological Sciences (miscellaneous)
Heart Valves
Microscopy, Electron
medicine.anatomical_structure
Ventricle
cardiovascular system
Cardiology
Electrical conduction system of the heart
business
Chickens
Subjects
Details
- ISSN :
- 0003276X
- Volume :
- 235
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- The Anatomical record
- Accession number :
- edsair.doi.dedup.....be1a847c089ac00c42f18a45bb249250