Biomaterial Database

Fractals describe blood flow heterogeneity within skeletal muscle and within myocardium. 1995

P O Iversen, and G Nicolaysen

Department of Physiology, University of Oslo, Norway.

A marked perfusion heterogeneity exists within single skeletal muscles and within the left ventricular (LV) myocardium. The relative dispersion (RD) of blood flows to regions < 1 g amounts to approximately 0.35 in both organs in rabbits. RD is changed with refinement of spatial resolution because the observed variance in regional flows increases. It has been shown with fractal analyses that the fractal dimension (D) can describe the relationship between the measured RD and size of the region studied within both the myocardium and the lung. A similar study has not been done with skeletal muscle. Barbital-anesthetized rabbits, cats, and sheep were used. Regional blood flow distribution was assessed with the microsphere method. Microsphere deposition in organ regions was determined after successive regrouping of either the LV or one skeletal muscle into various sized regions. We found that the perfusion patterns could be described with fractals for both organs, with the corresponding D values of 1.22-1.37 for the myocardium and 1.30-1.46 for muscle. It appears that fractals also yield a good description of blood flow distribution within skeletal muscle. In rabbits, D for myocardium was strongly correlated to the D for muscle (correlation coefficient = 0.98). This surprising finding of the strong correlation in D sampled from two organs originating from the same rabbit has hitherto not been reported.

UI	MeSH Term	Description	Entries
D009929	Organ Size	The measurement of an organ in volume, mass, or heaviness.	Organ Volume,Organ Weight,Size, Organ,Weight, Organ
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D012039	Regional Blood Flow	The flow of BLOOD through or around an organ or region of the body.	Blood Flow, Regional,Blood Flows, Regional,Flow, Regional Blood,Flows, Regional Blood,Regional Blood Flows
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D003326	Coronary Circulation	The circulation of blood through the CORONARY VESSELS of the HEART.	Circulation, Coronary
D003331	Coronary Vessels	The veins and arteries of the HEART.	Coronary Arteries,Sinus Node Artery,Coronary Veins,Arteries, Coronary,Arteries, Sinus Node,Artery, Coronary,Artery, Sinus Node,Coronary Artery,Coronary Vein,Coronary Vessel,Sinus Node Arteries,Vein, Coronary,Veins, Coronary,Vessel, Coronary,Vessels, Coronary
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012756	Sheep	Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.	Ovis,Sheep, Dall,Dall Sheep,Ovis dalli
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species
D017709	Fractals	Patterns (real or mathematical) which look similar at different scales, for example the network of airways in the lung which shows similar branching patterns at progressively higher magnifications. Natural fractals are self-similar across a finite range of scales while mathematical fractals are the same across an infinite range. Many natural, including biological, structures are fractal (or fractal-like). Fractals are related to "chaos" (see NONLINEAR DYNAMICS) in that chaotic processes can produce fractal structures in nature, and appropriate representations of chaotic processes usually reveal self-similarity over time.	Fractal