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Muscle Fiber Types
Published in Charles Paul Lambert, Physiology and Nutrition for Amateur Wrestling, 2020
Capillaries are the small vessels in between arterioles and venules (i.e., in between the arterial side of the body and venous side of the body). Capillaries are the blood delivery apparatus of the circulatory system. They deliver blood and remove metabolic by-products from the muscle. With training, the number of capillaries per muscle fiber goes up. Clearly, this is a good thing from both a metabolic by-product removal perspective and from a nutrient and oxygen delivery perspective. This means that the greater number of capillaries the greater perfusion of the muscle tissue in question. This results in better oxygen and nutrient delivery and the removal of hydrogen ions and lactic acid. This means that from the middle of the muscle fiber to the capillaries, the distance is decreased which allows for oxygen and nutrient delivery and the removal of metabolic by-products, to occur faster. This is a good thing for a wrestler as this means his physiology has improved. Interestingly, strength training with heavy weights without any other type of training will actually decrease capillary density relative to muscle fiber size as the distance from capillary to the middle of the muscle cell will become greater. This makes it more difficult to deliver oxygen-rich blood and nutrients (glucose, fatty acids, amino acids) and remove metabolic waste products (hydrogen ions and lactic acid) (Hudlicka 2011).
The Science Banqueting Table
Published in Jazlin Ebenezer, Hark, Hark! Hear the Story of a Science Educator, 2020
In line with the tradition of phenomenographic research, teaching did not focus on eradicating children’s everyday or “street” language because it is well-accepted for common use to function in their daily life. However, science discourse (with proper language labels) in the science classroom is important for socializing young learners into the scientific academic community (Brown & Ryoo, 2008; Wenger, 1998). Therefore, the teacher’s specially designed instruction enabled students to perform relational talk or distinguish the contexts in which everyday talk and science talk are appropriate. She helped students to conduct the science talk with science labels in science class, thus inducing relational conceptual change. Students were helped to attach language labels such as “metabolism, metabolic wastes, and nitrogenous wastes” to their understanding. In fact, five students refer to waste as “nitrogenous waste” and three refer to it as “metabolic waste” (see Table 4.1 section a).
The Plant Kingdom
Published in Spyridon E. Kintzios, Maria G. Barberaki, Evangelia A. Flampouri, Plants That Fight Cancer, 2019
Some secondary metabolites are considered as metabolic waste products, e.g. alkaloids may function as nitrogen waste products. However, a significant portion of the products derived from secondary pathways serve either as protective agents against various pathogens (e.g. insects, fungi, or bacteria) or growth regulatory molecules (e.g. hormone-like substances that stimulate or inhibit cell division and morphogenesis). Due to these physiological functions, secondary metabolites are potential anticancer drugs, since either direct cytotoxicity is effected on cancer cells or the course of tumor development is modulated and eventually inhibited. Administration of these compounds at low concentrations may be lethal for microorganisms and small-sized animals, like herbivore insects; however, they affect, more or less specifically, the fastest growing tissues (such as tumors) in a larger organism, as well as humans. Cancer cytotoxic compounds may also act as cancer chemopreventive agents, by inhibiting tumor- and metastasis-specific molecular pathways. A representative list of such targeted properties of plant-derived compounds is presented in Table 2.1.
Algal extracellular polymeric substances (algal-EPS) for mitigating the combined toxic effects of polystyrene nanoplastics and nano-TiO2 in Chlorella sp.
Published in Nanotoxicology, 2023
Lokeshwari Natarajan, M. Annie Jenifer, Willie J. G. M. Peijnenburg, Amitava Mukherjee
One of the critical gaps in the current ecotoxicological studies of nanomaterials lies in ignoring the role of naturally occurring biopolymers in modulating their physico-chemical as well as biological interactions. Extracellular Polymeric Substances (EPS) areone such natural biopolymer that often functions as a barrier to pollutants. EPS constitutes a key component of microalgae. Algae produce EPS for a variety of reasons, including (a) secure attachment and improvement of the local environment, and (b) as a metabolic waste. Notably, EPS secretion boosts cell survival, metabolic efficacy, and adaptability (Decho and Gutierrez 2017). These biopolymers can easily adsorb to nanomaterials in the aquatic environment, modulating their bioactivity, cytotoxicity, and physiological features (Alimi et al. 2018). This phenomenon is often referred to as eco-corona formation, the effects of which need to be considered while formulating an experimental design for nano-ecotoxicity studies in aquatic organisms.
Manganese mitigates against hepatorenal oxidative stress, inflammation and caspase-3 activation in rats exposed to hexachlorobenzene
Published in Drug and Chemical Toxicology, 2022
Abiola S. Tijani, Olori O. David, Ebenezer O. Farombi
Serum creatinine, cystatin-c, urea, uric acid and electrolytes are often used as indices for evaluating kidney function to ascertain kidney injury (Mahgoub et al. 2017, Zhang et al. 2018). Creatinine, urea and uric acid are normal metabolic waste products excreted by the kidneys. Cystatin-c with blood urea and creatinine is used to assess renal function and glomerular filtration rate (GFR) (Al-Kuraishy et al. 2019). Acute nephrotoxicity has been linked to electrolyte disturbances and dehydration. Considerable serum elevation of Na+, K+, HCO3−, and Cl− levels is of toxicological implication and may denote a consequence on the ion-dependent processes. Thus, the significant increases in these kidney function indices in rats administered with HCB alone suggest kidney’s excretory dysfunction, reduction of GFR and glomerular filtration (Health Council of the Netherlands 2011, Odden et al. 2014, Zhang et al. 2018). The reduced levels of these kidney function indices in HCB and Mn co-treated rats revealed the ameliorating effect of Mn on HCB-induced renal toxicity.
Royal jelly abrogates flouride-induced oxidative damage in rat heart tissue by activating of the nrf-2/NF-κB and bcl-2/bax pathway
Published in Toxicology Mechanisms and Methods, 2021
Abdullah Aslan, Seda Beyaz, Ozlem Gok, Muhammed Ismail Can, Gozde Parlak, Ibrahim Hanifi Ozercan, Ramazan Gundogdu
The cardiovascular system is a large scale network system through which blood is distributed throughout the body. It performs two important tasks: Providing oxygen and nutrients for our body organs and removing metabolic waste products from tissues. The central organ of the cardiovascular system is the heart, a closed fist-sized muscular organ located in the middle of the chest cavity between our two lungs. The average weight of a heart is 300-350 grams for men and 250-300 grams for women. ( Ilhan 2016). Useful products, food products and medicines used in daily life contain significant amounts of fluoride. Fluorine is the 13th most abundant chemical element in the world, and fluoride is its anionic form. Fluoride affects almost all organs and the functions of the living organism. While the fluoride taken in certain amounts contributes to the development of the bones and teeth of the human body, excessive amounts of fluoride are dangerous for the human body. Fluoride taken in excessive amounts causes damage to the heart tissue from cytotoxic substances for many organs. Studies conducted over the last decade have shown that excessive fluoride consumption has adverse effects on different organs and systems. Many studies have shown that fluoride is required for neurological, reproductive, hepatic, immunological, cardiac, nephrological, neurological, bone, dental development. It has been determined that it is a factor causing various toxicities (Sharma et al. 2017). Recent studies has shown that Royal jelly may have a cardioprotective effect on paclitaxel-induced cardiotoxicity in rats (Malekinejad et al. 2016).