National Repository of Grey Literature 8 records found  Search took 0.00 seconds. 
His bundle in phylogenesis, ontogenesis and pathology
Tremerová, Aneta ; Gregorovičová, Martina (advisor) ; Kolář, David (referee)
His bundle is a part of the cardiac conduction system of mammals, birds and crocodilians. His bundle is important for high cardiac output in endothermic vertebrates. His bundle is a connection between atria and ventricles in fibrous atrioventricular isolation and it serves as an electrical conduction pathway via bundle branches to ventricular apex, where ventricular contraction begins. Defect in cardiac conduction system leads to cardiac arrhytmia and can cause sudden cardiac death. Thesis describes development of His bundle in mammals and birds, its phylogenensis and atrioventricular conduction in other vertebrates. Thesis also describes disorders of atrioventricular canal development, fibrous anulus and His bundle such a preexcitation syndromes and congenital heart block. Thesis also depicts history of a discovery of the atrioventricular conduction tissue. Key words: cardiac conduction system, His bundle, atrioventricular canal, anulus fibrosus, ventricular preexcitation, perinatal AVRT, WPW syndrome, congenital heart block
Effect of incubation temperature on growth of the working and conducting myocardium in the embryonic chick
Skuhrová, Kristýna ; Sedmera, David (advisor) ; Gregorovičová, Martina (referee)
It was shown almost 50 years ago that hypothermic incubation of chicken embryos results in a reduction in the size of embryos and an increase in the heart weight, presumably by hypertrophy (increase in cell volume). The chicken embryos were incubated in normothermia (37.5 ř C) and hypothermia (33.5 ř C) from the eleventh embryonic day. On the 17th day, the embryos were weighed and then their hearts were weighed. In agreement with the previous results, hypothermic embryos were 29% smaller and their hearts 18% heavier. The heart-to-body weight ratio was 67% higher in the hypothermic group. The measured cell size was very similar in the target areas and it was also between the two groups. The left ventricle width was twofold that the right one and the difference was not significantly higher in the hypothermia model. Purkinje fibers, the terminal part of the conduction system, were smaller than the working cardiomyocytes. Purkinje fibers were slightly enlarged after hypothermic incubation. The proliferation rate was measured by immunohistochemical labeling of anti-phospho histone H3. The experimental group showed much higher proliferation rate; it reached statistical significance in the right ventricle. Thus, hypothermic incubation resulted in increased growth of embryonic heart based on hyperplasia...
Role of individual chemical compounds of repellent secretion of Graphosoma lineatum towards different predator species
Gregorovičová, Martina ; Horáček, Ivan (advisor) ; Veselý, Petr (referee) ; Zápotocký, Martin (referee)
The chemical defence of Heteroptera is based on the repellent secretion that is very complex and consists of dozens chemical compounds. Heteroptera have good ability to produce/store large amounts of chemical components. The repellent secretion of Graphosoma lineatum is composed of many chemicals, such as short-chained aldehydes, which may signal the unpalatability of the bug to its potential predators or be directly toxic for them. The thesis is aimed at the major components of defensive secretion of Graphosoma lineatum - aldehydes - as well as the whole metathoracic scent-glands secretion of Graphosoma lineatum. The aversive reactions of four selected predators were evaluated: (1) leopard gecko (Eublepharis macularius); (2) green lizard (Lacerta viridis); (3) great tit (Parus major) and (4) blue tit (Cyanistes caeruleus). The following major compounds of the repellent secretion were tested: (1) the mixture of three aldehydes: (E)-hex-2-enal, (E)-oct-2-enal, (E)-dec-2-enal; (2) the mixture of three aldehydes and tridecane; (3) oxoaldehyde: (E)-4-oxohex-2-enal; (4) extracted metathoracic scent-glands secretion of Graphosoma lineatum adults; (5) hexane as a non-polar solvent and (6) pyrazine: 2-isobutyl-3-methoxypyrazine in experiments with leopard geckos as a positive control for excluding the...
Role of individual chemical compounds of repellent secretion of Graphosoma lineatum towards different predator species
Gregorovičová, Martina
The chemical defence of Heteroptera is based on the repellent secretion that is very complex and consists of dozens chemical compounds. Heteroptera have good ability to produce/store large amounts of chemical components. The repellent secretion of Graphosoma lineatum is composed of many chemicals, such as short-chained aldehydes, which may signal the unpalatability of the bug to its potential predators or be directly toxic for them. The thesis is aimed at the major components of defensive secretion of Graphosoma lineatum - aldehydes - as well as the whole metathoracic scent-glands secretion of Graphosoma lineatum. The aversive reactions of four selected predators were evaluated: (1) leopard gecko (Eublepharis macularius); (2) green lizard (Lacerta viridis); (3) great tit (Parus major) and (4) blue tit (Cyanistes caeruleus). The following major compounds of the repellent secretion were tested: (1) the mixture of three aldehydes: (E)-hex-2-enal, (E)-oct-2-enal, (E)-dec-2-enal; (2) the mixture of three aldehydes and tridecane; (3) oxoaldehyde: (E)-4-oxohex-2-enal; (4) extracted metathoracic scent-glands secretion of Graphosoma lineatum adults; (5) hexane as a non-polar solvent and (6) pyrazine: 2-isobutyl-3-methoxypyrazine in experiments with leopard geckos as a positive control for excluding the...
Food preferences and foraging mode in lizards (Squamata: Sauria)
Křivánek, Jan ; Gregorovičová, Martina (advisor) ; Kubička, Lukáš (referee)
In terms of food-foraging, lizards usually occupy one of two possible strategies ("foraging mode"). The first one is called "sit and wait" and it is defined by waiting on one position for a long time with a minimum movements and attack is based on visual cues on prey which gets to a certain distance. The second one is the "active foraging" in which the predator moves through terrain and it detects with help of chemical cues by nasal olfactoric system or vomeronasal system, with which is able to find a prey. Sometimes the third mode is also presented as a transition - "saltatory foraging" or a continuum between two these extreme strategies. Specific variables, which reflects the activity of a predator, are used to determine the "foraging mode" - MPM, PTM, PAM and AD. Within these predators a whole set of sensory adaptations ( such as enlarged olfactory lobes, a large abundance of taste buds, two fovea centralis in macula), morphological adaptations (e.g.shortening of the jaw, slender body morphology, forked tongue) and food adaptations (yellow color preference, ontogenetic shift to herbivory) are presented. Powered by TCPDF (www.tcpdf.org)
Discrimination and generalization of prey in lizards (Squamata: Sauria)
Vohralík, Martin ; Gregorovičová, Martina (advisor) ; Schořálková, Tereza (referee)
The ability to find and recognize palatable prey is fundamental for survival of any organism. Here we are discussing different ways of recognition of such a prey in order Squamata and the ways they learn this discrimination. Lizards are well known for their ability to analyse chemical cues brought from their tongue to the Jacobson's organ, which is completely separate from the nassal cavity in Squamata. However, the leading sense used for discrimination in Squamata can also be vision or other forms of chemoreception. Dominance of one sense can be assesed from morphology of tongue and abundance of taste buds or ecological strategy used for hunting a prey. Once the predator learns which cue to discriminate, it can generalise similar cues. Powered by TCPDF (www.tcpdf.org)
Hormonal control of aggressive behaviour in lizards
Rauner, Petr ; Kratochvíl, Lukáš (advisor) ; Gregorovičová, Martina (referee)
Aggression is a highly functional form of social behaviour, which can be observed in nearly all species of vertebrates including lizards. There are many forms of aggressive behaviour and there is very significant difference in the physiological basis among them. The main and best understood hormone affecting aggression, is testosterone, but there exists evidence that some aggressive behaviour can be influenced by other hormones as well for example by progesterone, estradiol and corticosterone. The effect of these hormones on the organism is traditionally divided into the activation and organizational effects. Organizational effects are permanent and occur usually in the earlier stages of development. Activation effects are temporary and occur during the entire life. Elevated testosterone levels usually stimulate aggressive behaviour in both males and females. Progesterone and estradiol affect aggressive behaviour similarly but less effective. It is uncertain whether their effects are direct, or whether they are only a side-effect of testosterone, which is a precursor of estradiol and which has progesterone as own precursor. Corticosterone affects aggressive behaviour indirectly by influencing levels of testosterone. Hormonal influence on aggression in lizards is not the sole factor, but it depends on...

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