Comparative anatomy of the cardiac foramen ovale in the Pinnipedia

Macdonald, Alastair A.; Dixon, Christopher; Boyd, Ian L.

doi:10.1139/z95-100

Cited by 4 publications

(3 citation statements)

References 15 publications

(20 reference statements)

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“…Possibly, the secondary foramen is relatively small in rodents, but the configuration in rodents (order Rodentia) resembles those of human and other primates (Franklin et al ., ; Anderson et al, ). In carnivores (order Carnivora), there is a single large secondary foramen, but this may come at the end of a short sleeve‐like extension of the primary septum, which projects into the left atrial lumen (Franklin et al ., ; Macdonald et al, ; Macdonald and Johnstone, ). Among odd‐toed ungulates (order Perissodactyla, e.g., horse) and even‐toed ungulates (order Artiodactyla, e.g., sheep and whales), the setting can become extreme (Fig.…”

Section: Normal Development Of the Atrial Septum In Eutherian Mammalsmentioning

confidence: 98%

Evolution and Development of the Atrial Septum

Jensen

Wang

Moorman

2018

The Anatomical Record

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The complete division of the atrial cavity by a septum, resulting in a left and right atrium, is found in many amphibians and all amniotes (reptiles, birds, and mammals). Surprisingly, it is only in eutherian, or placental, mammals that full atrial septation necessitates addition from a second septum. The high incidence of incomplete closure of the atrial septum in human, so‐called probe patency, suggests this manner of closure is inefficient. We review the evolution and development of the atrial septum to understand the peculiar means of forming the atrial septum in eutherian mammals. The most primitive atrial septum is found in lungfishes and comprises a myocardial component with a mesenchymal cap on its leading edge, reminiscent to the primary atrial septum of embryonic mammals before closure of the primary foramen. In reptiles, birds, and mammals, the primary foramen is closed by the mesenchymal tissues of the atrioventricular cushions, the dorsal mesenchymal protrusion, and the mesenchymal cap. These tissues are also found in lungfishes. The closure of the primary foramen is preceded by the development of secondary perforations in the septal myocardium. In all amniotes, with the exception of eutherian mammals, the secondary perforations do not coalesce to a secondary foramen. Instead, the secondary perforations persist and are sealed by myocardial and endocardial growth after birth or hatching. We suggest that the error‐prone secondary foramen allows large volumes of oxygen‐rich blood to reach the cardiac left side, needed to sustain the growth of the extraordinary large offspring that characterizes eutherian mammals. Anat Rec, 302:32–48, 2019. © 2018 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.

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Section: Normal Development Of the Atrial Septum In Eutherian Mammalsmentioning

confidence: 98%

Evolution and Development of the Atrial Septum

Jensen

Wang

Moorman

2018

The Anatomical Record

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“…King () determined that ductus arteriosus usually closes after six weeks in newborns, and in the common seal ( Phoca vitulina vitulina ), it remains anatomically and physiologically opened until three months of age, thus contradicting MacDonald et al. 's () findings, who stated that ductus arteriosus closed immediately after birth. According to Slijer (), in cetaceans and common seal, the ductus arteriosus closure can be explained by the fact that newborns swan and dive immediately after birth, and the storage of oxygen may generate temporary reopening of the duct in first periods of postnatal life, which delayed the anatomical closure.…”

Section: Discussionmentioning

confidence: 95%

“…This structure has been previously described in some species of pinnipeds (MacDonald et al . ) such as seal‐of‐hood ( Cystophora cristata ) (Drabek and Burns ) and common seal ( Phoca vitulina vitulina ) (King ), as well as in cetaceans like Franciscana (Pérez and Lima ), common porpoise ( Phocoena phocoena ), white‐peak‐dolphin ( Lagenorhynchus albirostris ), white flank dolphin ( Lagenorhynchus acutus ), common dolphin ( Delphinus Dephinus ), and bottlenose dolphin ( Tursiops truncatus ) (Van Nie ).…”

Section: Discussionmentioning

confidence: 99%

Adaptive morphology of the heart of Southern‐Fur‐Seal (Arctocephalus australis– Zimmermamm, 1783)

Guimarães

Mari²,

Bas

et al. 2013

Acta Zoologica

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The Southern‐fur‐seal belongs to the order Carnivora, suborder Pinnipedia, and Otariidae family. This species inhabits aquatic and terrestrial environments, thus presenting important morphophysiological adaptive changes, especially in the cardiac system. For this purpose, Southern‐fur‐seal (Arctocephalus australis) hearts were used from animals that died from natural causes. Gross morphology observations were supported by light, scanning and transmission electron microscopy. The heart was long and flat; it was lined by pericardium and partly covered by lungs. Structurally, atrium and ventricle muscle fibers exhibit typical features of cardiac fibers revealing myofibrils bundles, mitochondria, plate‐shaped junctions, anastomosis between myofibrils bundles, and electron‐dense granule natriuretic around the nucleus and mitochondria of atrium muscle cells. The Southern‐fur‐seal heart was structurally similar to other mammals; however, it presented morphological changes that assist in their adaptation to their environment.

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