Dynamics of blood circulation during diving in the bottlenose dolphin (Tursiops truncatus). The role of the retia mirabilia RESEARCH ARTICLE

Marco Bonato, Paola Bagnoli, Cinzia Centelleghe, Mike Maric, Ginevra Brocca, Sandro Mazzariol, and Bruno Cozzi The retia mirabilia are vascular nets composed by small vessels dispersed among numerous veins, allowing blood storage, regulation of flow, and pressure damping effects. Here we investigated their potential role during the diving phase of the bottlenose dolphin (Tursiops truncatus). To this effect, the whole vertebral retia mirabilia of a series of dolphins were removed during post-mortem analysis and examined to assess vessel diameters, estimate vascular volume, and flow rate. Here we formulate a new hemodynamic model to help clarify vascular dynamics throughout the diving phase, based on the total blood volume of a bottlenose dolphin, and using data available about the perfusion of the main organs and body systems. We computed the minimum blood perfusion necessary to the internal organs, and the stroke volume (sv) and cardiac output (co) during the surface state. We then simulated breath-holding conditions and perfusion of the internal organs under the diving-induced bradycardia and reduction of sv and co, using 10 bpm as limit for the heart rate for an extended dive of over 3 minutes. Within these simulated conditions, the retia mirabilia play a vital role as a reservoir of oxygenated blood that permit functional performances and survival of the heart and brain. Our theoretical model, based on the actual blood capacity of the retia mirabilia and available data on ...
Source: Journal of Experimental Biology - Category: Biology Authors: Tags: RESEARCH ARTICLE Source Type: research

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Conclusions The increase in HR rather than an increase in CBF or forearm venous volume was responsible for the decrease in SV during moderate-intensity exercise when Tsk was held at 38°C.
Source: Medicine and Science in Sports and Exercise - Category: Sports Medicine Tags: BASIC SCIENCES Source Type: research
ConclusionThere is evidence that frontal lobe perfusion is lower during orthostasis in individuals with AF, and that the presence of OH modifies this association.
Source: Age and Ageing - Category: Geriatrics Source Type: research
ConclusionThis study highlights the high prevalence of unidentified or poorly controlled VRF in people with mild cognitive symptoms attending a memory service. Given its importance to brain health and mitigation of future cognitive decline, a structured focus on identifying and managing these VRF in this setting is necessary. Exercise-based lifestyle programs should be embedded in post-diagnostic services for this population.
Source: Age and Ageing - Category: Geriatrics Source Type: research
ConclusionBased on IVIM analysis, cerebral microvascular structure and function showed no difference between hypertensive and normotensive patients with moderate-to-severe OSA treated with CPAP. Treatment adherence with antihypertensive drug regime and, in turn, controlled hypertension seems not to affect microvascular structure and perfusion of the brain.Trial registrationClinicalTrials.gov Identifier: NCT02493673
Source: Neuroradiology - Category: Radiology Source Type: research
Nature Reviews Neurology, Published online: 13 September 2019; doi:10.1038/s41582-019-0267-0Outdated knowledge of arterial perfusion territories still guides clinical decisions and management in acute and chronic stroke. In a new study, application of machine learning techniques provides more detail than ever before, laying the foundation for improved stroke management and new research.
Source: Nature Reviews Neurology - Category: Neurology Authors: Source Type: research
Baxter Healthcare is set to acquire Cheetah Medical, a firm an analyst identified earlier this year as one of 16 disruptive private companies in medtech. The transaction consists of an upfront cash consideration of $190 million, with potential for an additional $40 million based on clinical and commercial milestones. It is set to close in 4Q19. Boston and Tel Aviv, Israel-based Cheetah Medical is a major provider of non-invasive hemodynamic monitoring technologies. The addition of Cheetah Medical is expected to enhance Deerfield, IL-based Baxter’s presence in the specialized patient monitoring space with ...
Source: MDDI - Category: Medical Devices Authors: Tags: IV Products Business Source Type: news
The notion that stroke care could one day take to the skies seems more likely...Read more on AuntMinnie.comRelated Reading: Mobile CT unit boosts efficiency of stroke triage Perfusion imaging expands window for stroke treatment UCLA offers ambulatory stroke care with mobile CT Mobile stroke units, spectral CT take spots on ECRI watch list Mobile stroke unit with CT scanner speeds care in Cleveland
Source: AuntMinnie.com Headlines - Category: Radiology Source Type: news
Source: The Journal of Thoracic and Cardiovascular Surgery - Category: Cardiovascular & Thoracic Surgery Authors: Source Type: research
Abstract BACKGROUND: Previous studies have estimated that the risk of recurrent stroke was nearly 20% shortly after a transient ischemic attack (TIA) or minor stroke. A missing or hypoplastic (
Source: Brain Research - Category: Neurology Authors: Tags: Brain Res Source Type: research
We report a case of an intracranial hemorrhage first suspected during a trans-cranial Doppler assessment of a postorthotopic liver transplant patient. The patient was at considerable risk of bleeding, due to a primary graft nonfunction, but he had also elevated ammonium levels, justifying the comatose state, and no focal neurological deficits.
Source: Journal of Stroke and Cerebrovascular Diseases - Category: Neurology Authors: Tags: Case Report Source Type: research
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