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A Preliminary Study on the Siphon Mechanism in Giraffe ( Giraffa camelopardalis). Animals (Basel) 2022; 12:ani12233348. [PMID: 36496868 PMCID: PMC9740075 DOI: 10.3390/ani12233348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 11/23/2022] [Accepted: 11/26/2022] [Indexed: 12/04/2022] Open
Abstract
Adult giraffes reach heights of 4.5 m with a heart-to-head distance of over 2 m, making cranial blood supply challenging. Ultrasound confirmed that the giraffe jugular vein collapses during head movement from ground level to fully erect, negating the possibility of a siphon mechanism in the neck. We showed that a short-length siphon structure over a simulated head-to-heart distance for a giraffe significantly influences flow in a collapsible tube. The siphon structure is determined according to brain case measurements. The short-length siphon structure in a shorter-necked ostrich showed no significant increase in flow. The shorter head-to-heart distance might be the reason for the lack of effect in ostriches. A siphon mechanism situated in the cranium is certainly possible, with a significant effect exerted on the amount of pressure the heart must generate to allow adequate cranial blood perfusion in a long-necked giraffe. The study validated that a cranial-bound siphon structure can operate and will be of significant value for adequate cranial blood perfusion in long-necked species such as giraffes and might also have existed in extinct species of long-necked dinosaurs.
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Hong JM, Choi ES, Park SY. Selective Brain Cooling: A New Horizon of Neuroprotection. Front Neurol 2022; 13:873165. [PMID: 35795804 PMCID: PMC9251464 DOI: 10.3389/fneur.2022.873165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 05/23/2022] [Indexed: 11/17/2022] Open
Abstract
Therapeutic hypothermia (TH), which prevents irreversible neuronal necrosis and ischemic brain damage, has been proven effective for preventing ischemia-reperfusion injury in post-cardiac arrest syndrome and neonatal encephalopathy in both animal studies and clinical trials. However, lowering the whole-body temperature below 34°C can lead to severe systemic complications such as cardiac, hematologic, immunologic, and metabolic side effects. Although the brain accounts for only 2% of the total body weight, it consumes 20% of the body's total energy at rest and requires a continuous supply of glucose and oxygen to maintain function and structural integrity. As such, theoretically, temperature-controlled selective brain cooling (SBC) may be more beneficial for brain ischemia than systemic pan-ischemia. Various SBC methods have been introduced to selectively cool the brain while minimizing systemic TH-related complications. However, technical setbacks of conventional SBCs, such as insufficient cooling power and relatively expensive coolant and/or irritating effects on skin or mucosal interfaces, limit its application to various clinical settings. This review aimed to integrate current literature on SBC modalities with promising therapeutic potential. Further, future directions were discussed by exploring studies on interesting coping skills in response to environmental or stress-induced hyperthermia among wild animals, including mammals and birds.
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Affiliation(s)
- Ji Man Hong
- Department of Neurology, Ajou University School of Medicine, Ajou University Medical Center, Suwon, South Korea
- Department of Biomedical Science, Ajou University School of Medicine, Ajou University Medical Center, Suwon, South Korea
- *Correspondence: Ji Man Hong
| | - Eun Sil Choi
- Department of Biomedical Science, Ajou University School of Medicine, Ajou University Medical Center, Suwon, South Korea
| | - So Young Park
- Department of Neurology, Ajou University School of Medicine, Ajou University Medical Center, Suwon, South Korea
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Ekdale EG, Deméré TA. Neurovascular evidence for a co-occurrence of teeth and baleen in an Oligocene mysticete and the transition to filter-feeding in baleen whales. Zool J Linn Soc 2021. [DOI: 10.1093/zoolinnean/zlab017] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
Extant baleen whales (Mysticeti) have a deciduous foetal dentition, but are edentulous at birth. Fossils reveal that the earliest mysticetes possessed an adult dentition. Aetiocetids, a diverse clade of Oligocene toothed mysticetes, have a series of small palatal foramina and associated sulci medial to the postcanine dentition. The openings have been homologized with lateral palatal foramina that transmit neurovascular structures to baleen in extant mysticetes, thereby implying a co-occurrence of teeth and baleen in aetiocetids. However, homology of the foramina and sulci have been questioned. Using CT-imaging, we report that the lateral palatal foramina of Aetiocetus weltoni are connected internally to the superior alveolar canal, which transmits neurovascular structures to baleen in extant mysticetes and to teeth in extant odontocetes. Furthermore, the lateral palatal foramina of Aetiocetus are separate from the more medially positioned canals for the greater palatine arterial system. These results provide critical evidence to support the hypothesis that the superior alveolar neurovasculature was co-opted in aetiocetids and later diverging mysticetes to serve a new function associated with baleen. We evaluate competing hypotheses for the transition from teeth to baleen, and explore the transition from raptorial feeding in early mysticetes to filter-feeding in extant species.
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Affiliation(s)
- Eric G Ekdale
- Department of Biology, San Diego State University, Campanile Drive, San Diego, CAUSA
- Department of Paleontology, San Diego Natural History Museum, El Prado, San Diego, CA, USA
| | - Thomas A Deméré
- Department of Paleontology, San Diego Natural History Museum, El Prado, San Diego, CA, USA
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MacPhee R, Del Pino SH, Kramarz A, Forasiepi AM, Bond M, Sulser RB. Cranial Morphology and Phylogenetic Relationships of Trigonostylops wortmani, an Eocene South American Native Ungulate. BULLETIN OF THE AMERICAN MUSEUM OF NATURAL HISTORY 2021. [DOI: 10.1206/0003-0090.449.1.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- R.D.E. MacPhee
- Department of Mammalogy/Vertebrate Zoology and Richard Gilder Graduate School, American Museum of Natural History
| | | | - Alejandro Kramarz
- Sección Paleontología de Vertebrados, Museo Argentino de Ciencias Naturales Bernardino Rivadavia, CONICET, Buenos Aires, Argentina
| | | | - Mariano Bond
- Departamento Científico de Paleontología Vertebrados, Museo de La Plata, Paseo del Bosque s/n, 1900 La Plata, Argentina
| | - R. Benjamin Sulser
- Department of Mammalogy/Vertebrate Zoology and Richard Gilder Graduate School, American Museum of Natural History
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Buser TJ, Boyd OF, Cortés Á, Donatelli CM, Kolmann MA, Luparell JL, Pfeiffenberger JA, Sidlauskas BL, Summers AP. The Natural Historian's Guide to the CT Galaxy: Step-by-Step Instructions for Preparing and Analyzing Computed Tomographic (CT) Data Using Cross-Platform, Open Access Software. Integr Org Biol 2020; 2:obaa009. [PMID: 33791553 PMCID: PMC7671151 DOI: 10.1093/iob/obaa009] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The decreasing cost of acquiring computed tomographic (CT) data has fueled a global effort to digitize the anatomy of museum specimens. This effort has produced a wealth of open access digital three-dimensional (3D) models of anatomy available to anyone with access to the Internet. The potential applications of these data are broad, ranging from 3D printing for purely educational purposes to the development of highly advanced biomechanical models of anatomical structures. However, while virtually anyone can access these digital data, relatively few have the training to easily derive a desirable product (e.g., a 3D visualization of an anatomical structure) from them. Here, we present a workflow based on free, open source, cross-platform software for processing CT data. We provide step-by-step instructions that start with acquiring CT data from a new reconstruction or an open access repository, and progress through visualizing, measuring, landmarking, and constructing digital 3D models of anatomical structures. We also include instructions for digital dissection, data reduction, and exporting data for use in downstream applications such as 3D printing. Finally, we provide Supplementary Videos and workflows that demonstrate how the workflow facilitates five specific applications: measuring functional traits associated with feeding, digitally isolating anatomical structures, isolating regions of interest using semi-automated segmentation, collecting data with simple visual tools, and reducing file size and converting file type of a 3D model.
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Affiliation(s)
- T J Buser
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, USA
| | - O F Boyd
- Department of Integrative Biology, Oregon State University, Corvallis, OR, USA
| | - Á Cortés
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, USA
| | - C M Donatelli
- Department of Biology, University of Ottawa, Ottawa, ON, USA
| | - M A Kolmann
- Department of Biological Sciences, George Washington University, Washington, DC, USA
| | - J L Luparell
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, USA
| | | | - B L Sidlauskas
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, USA
| | - A P Summers
- Department of Biology and SAFS, University of Washington, Friday Harbor Laboratories, Friday Harbor, Washington, DC, USA
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O'Brien HD. From Anomalous Arteries to Selective Brain Cooling: Parallel Evolution of the Artiodactyl Carotid Rete. Anat Rec (Hoboken) 2018; 303:308-317. [PMID: 30421534 DOI: 10.1002/ar.23987] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 12/19/2017] [Accepted: 01/08/2018] [Indexed: 11/05/2022]
Abstract
Terrestrial artiodactyls (even-toed ungulates) inhabit some of the world's most extreme environments, including arid deserts and high elevations. As medium-to-large-bodied mammals, artiodactyls have a suite of specialized physiologies to facilitate occupation of regions unavailable to other large mammals. One such physiology is selective brain cooling, wherein reduction of brain temperature below core body temperature has been demonstrated to reduce evaporative water loss. This physiology is enabled by an arterial heat-exchanger called the carotid rete. The ubiquity of the carotid rete throughout the clade, as well as its evolutionary history, is currently uninvestigated. Here, I use osteological correlates to survey clade-wide presence and morphology of the carotid rete, prior to conducting a preliminary evolutionary analysis. Nearly all living artiodactyls possess a carotid rete and are capable of selective brain cooling; however, major arteries supplying the rete are derived from different embryonic aortic arches on a suborder-specific basis. Ancestral character estimation infers this pattern of variation to be the result of independent evolutionary processes, suggesting carotid rete homoplasy arising via parallelism. This is a surprising finding given the role this structure plays in driving a physiology that has been implicated in mitigating artiodactylan responses to extreme environmental conditions. Future studies should incorporate extinct species represented in the fossil record to better parse between parallel and convergent mechanisms, as well as to better understand the relationship between the carotid rete, selective brain cooling, and survivorship of climate perturbation. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. Anat Rec, 303:308-317, 2020. © 2018 American Association for Anatomy.
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Affiliation(s)
- Haley D O'Brien
- Department of Anatomy and Cell Biology, Oklahoma State University Center for Health Sciences, Tulsa, Oklahoma
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Kowalczyk K, Zdun M, Frąckowiak H. Arterial Patterns of the Face in Camelidamorpha. Anat Rec (Hoboken) 2018; 301:2122-2127. [PMID: 30299592 DOI: 10.1002/ar.23952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 02/10/2018] [Accepted: 04/01/2018] [Indexed: 11/07/2022]
Abstract
Arteries supplying the intermandibular, mental, masseteric, buccal, labial, and nasal regions of the face in selected species belonging to the suborder Tylopoda are described in this study. Analyses were conducted on a total of five species representing the family Camelidae based on 27 heads of cadaveric specimens, which were prepared by arterial injection with acetone-dissolved stained vinyl super chloride or stained latex LBS3060. Vascularization of regions of the face was formed by the facial, sublingual, mental, transverse facial, buccal, and infraorbital arteries. It was confirmed that the linguofacial trunk is absent in Camelidae. In turn, in camels the deep temporal artery descended in the common trunk with the transverse facial artery, while in llamas and alpacas it was a direct branch of the maxillary artery. It was shown that the pattern of facial arteries in Camelidamorpha exhibits specific traits for this clade and differs from the system of these arteries in other artiodactyls. The described specific character in arterial vascularization of the face not only expands the spectrum of morphological characteristics in Camelidae, but it also provides information which may prove useful for clinical purposes in veterinary practice. Anat Rec, 301:2122-2127, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Karolina Kowalczyk
- Department of Anatomy of Animals, Poznan University of Life Sciences, Poznań, Poland
| | - Maciej Zdun
- Centre for the Veterinary Sciences at the Nicolaus Copernicus University in Toruń, Toruń, Poland
| | - Hieronim Frąckowiak
- Department of Anatomy of Animals, Poznan University of Life Sciences, Poznań, Poland
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