AI Article Synopsis
- Adult giraffes reach heights of 4.5 m, posing challenges for blood supply to the brain due to their long necks.
- Research using ultrasound showed that the giraffe's jugular vein collapses when the head is raised, ruling out a siphon effect in their necks.
- The study indicates that a cranial siphon mechanism could help maintain blood flow to the brain in long-necked animals like giraffes, and this idea may also apply to long-necked dinosaurs.
Article 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.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9740075 | PMC |
| http://dx.doi.org/10.3390/ani12233348 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Habitat-specific regulation of microbiota in long-distance water diversion systems.
Water Res
February 2025
Institute of Loess Plateau, Shanxi University, Taiyuan 030006, Shanxi, China. Electronic address:
Long-distance water diversion projects typically utilize various hydro-engineering facilities, creating complex and dynamic habitats. However, the microbial dynamics of multi-trophic microorganisms during water diversion and their responses to different hydro-engineering habitats remain poorly understood. In this study, we investigated bacteria, fungi, protists, and metazoa across tunnels, reservoirs, and inverted siphon piping along the main and northern branches of the Yellow River Diversion Project into Shanxi, during spring, summer, and autumn.
View Article and Find Full Text PDFClam Genome and Transcriptomes Provide Insights into Molecular Basis of Morphological Novelties and Adaptations in Mollusks.
Biology (Basel)
October 2024
State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China.
Bivalve mollusks, comprising animals enclosed in two shell valves, are well-adapted to benthic life in many intertidal zones. Clams have evolved the buried lifestyle, which depends on their unique soft tissue structure and their wedge-shaped muscular foot and long extendible siphons. However, molecular mechanisms of adaptative phenotype evolution remain largely unknown.
View Article and Find Full Text PDFComputational hemodynamic pathophysiology of internal carotid artery blister aneurysms.
Biomed Eng Online
November 2024
Division of Neurosurgery, Centre Hospitalier de L'Université de Montréal, Montréal, QC, Canada.
Objective: Blister aneurysms of the internal carotid artery (ICA) are rare and are primarily documented in the literature through small series and case reports. The intraoperative observation of a hemorrhage in the artery wall proximal to the aneurysmal bulge led to the hypothesis that some of these aneurysms might develop in a retrograde manner.
Methods: We developed software to reconstruct the ICA with and without Type I and II blister aneurysms using patients' imagery as input to simulate hemodynamic conditions before and after their formation.
In the context of building a modern industrial system, digital finance inclusive (DFI) and environmental regulation (ER) have become significant drivers of industrial structure upgrading. Amid the rapid development of DFI and the tightening of ER, high-quality development goals have been set. From a spatial perspective, can DFI, ER, and their interactions positively impact China's industrial structure? Based on panel data from 30 provinces in China from 2011 to 2020, empirical analysis is conducted using the Spatial Durbin Model and the Threshold Model.
View Article and Find Full Text PDFModulating metal-centered dimerization of a lanthanide chaperone protein for separation of light lanthanides.
Proc Natl Acad Sci U S A
November 2024
Department of Chemistry, The Pennsylvania State University, University Park, PA 16802.
Elucidating details of biology's selective uptake and trafficking of rare earth elements, particularly the lanthanides, has the potential to inspire sustainable biomolecular separations of these essential metals for myriad modern technologies. Here, we biochemically and structurally characterize () LanD, a periplasmic protein from a bacterial gene cluster for lanthanide uptake. This protein provides only four ligands at its surface-exposed lanthanide-binding site, allowing for metal-centered protein dimerization that favors the largest lanthanide, La.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!