Anaerobic endurance: the speed endurance sports
Nick Draper, Helen Marshall in Exercise Physiology, 2014
Acids, such as lactic acid, dissociate in solution to release their H+, increasing acidity. Bases, such as ammonia (NH3) which is produced during the adenylate kinase reaction (described in Chapter 9), accept H+ in solution to form hydroxide ions (OH−) thereby increasing alkalinity. The acid-base balance of solution depends on the concentration of hydrogen and hydroxide ions present. Where H+ > than OH− the solution is acidic, when H+ = OH− the solution is neutral, and when H+ < OH− the solution is alkaline. The maintenance of blood pH within tolerable limits is essential to life. Acidosis arising in diseases such as diabetes, and alkalosis in response to the low PO2 at altitude, are potentially fatal if left untreated. The body’s buffering mechanisms (discussed below), which operate within all the body’s fluids (i.e. intracellular and extracellular fluid, and plasma within the blood), are responsible for maintaining pH at rest and importantly during exercise.
Food Types, Dietary Supplements, and Roles
Chuong Pham-Huy, Bruno Pham Huy in Food and Lifestyle in Health and Disease, 2022
The pH is a measure of the acid-base balance of a solution or a water. The pH (potential Hydrogen) measures the concentration of free hydrogen ions in a solution. The pH scale ranges from 0 (the most acidic) to 14 (the most basic), with 7 as the neutral mid-point. Most tap water and a number of spring and natural mineral waters have a pH around 7. Human blood has a pH of approximately 7.4 ± 0.05. It is essential for our bodies to maintain our blood pH within a tight range. Even a small fluctuation of as little as .05 in our blood pH can have severe health risks. However, the pH of the organs throughout the rest of the body can vary widely. In our stomach, the pH is acidic and varies from 1.5 to 3.5 during food digestion, while the pH of pancreatic juice is alkaline from 7.5–8.0.
Blood gas interpretation
Philip Woodrow in Nursing Acutely Ill Adults, 2015
pH (‘puissance d’hydrogène’ – power of hydrogen) is a scale to identify acidity or alkalinity of chemicals. The scale ranges from 0 (strongest possible acid) to 14 (strongest possible alkali), with a chemically neutral point of 7.0 (pure water). Blood is chemically slightly alkaline, so arterial blood below 7.35 is described as acidosis, while pH >7.45 is alkalosis. Significantly lower pH can be found is some parts of the body (e.g. stomach, urine), but blood pH below 6.8 or above 7.8 is usually rapidly fatal (Hennessey and Japp, 2007). Blood pH is the sum of respiratory and metabolic acid/base balance. To maintain homeostasis, the body attempts to compensate for an imbalance of one with an equal and opposite reaction with the other (see step 4 below). pH imbalance may therefore be respiratory, metabolic, or mixed.
The role of the clinical laboratory in diagnosing acid–base disorders
Published in Critical Reviews in Clinical Laboratory Sciences, 2019
Acid–base balance is maintained by a complex interplay of many organ systems including brain, lungs, kidney, and liver. Despite its importance, the physiology of acid–base metabolism seems to be an unpopular topic of medicine due to its complexity and the confusing, simultaneous use of different concepts and nomenclatures [1]. Accurate and timely interpretation of an acid–base disorder can be lifesaving, but the establishment of a correct diagnosis may be challenging [2,3]. Textbook presentation of symptoms may speed diagnosis and treatment, but in clinical practice, many areas of uncertainty remain in the early and even the advanced stages of a disease [4]. History and physical examination may give important clues for diagnosing acid–base disorders, as can be seen in Table 1, but obvious clinical signs are often lacking. Consequently, measurement and integration of laboratory parameters into the clinical pictures is fundamental in establishing the diagnosis in acid–base disorders. Fortunately, important acid–base results are often available within minutes in the acute hospital care setting [5]. This review focuses on the most important laboratory factors in diagnosing these disorders.
Clinical and genetic analysis of distal renal tubular acidosis in three Chinese children
Published in Renal Failure, 2018
Jiaojiao Liu, Qian Shen, Guomin Li, Yihui Zhai, Xiaoyan Fang, Hong Xu
Acid-base homeostasis is critical for normal growth and development and the maintenance of normal cellular function. Alkali therapy is the conventional therapy used to maintain systemic homeostasis. For each patient, treatment with potassium citrate was initiated at diagnosis, and the dose of citrate was regulated based on the blood pH and biochemical findings. During the follow-up, two patients (except for Patient-3) achieved the average height with alkali therapy by the final follow-up (1 year). After three years of potassium citrate treatment, Patient-3 failed to exhibit the normal growth (<p25th). His bone age was delayed by 3 years, and the insulin stimulation tests revealed a peak serum GH concentration of 10 μg/l. Due to the poor growth and parental expectations, we initiated recombinant human growth hormone (rhGH) therapy in patient-3 at 6 years of age. The average dose of rhGH was 0.05 mg/kg daily. After 10 months of rhGH therapy, he grew at an average rate of 9.6 cm per year, which was considerable increased following the initiation of the growth hormone therapy (3 cm/yr), and he achieved the average height for his age and gender (Figure 1).
Strong ions and charge-balance
Published in Scandinavian Journal of Clinical and Laboratory Investigation, 2023
It appears that Bie [27] has no means to predict the pH in a fluid of SID constituents alone, whereas the results obtained with charge-balance since Koppel and Spiro [5] are likely to be reliable [15]. It is certainly true that experiments in a beaker can hardly on their own emulate the complexities of biological systems, but on the other hand the three fundamental principles of electroneutrality, mass conservation and known rules of dissociation cannot be dispensed with, either. Bie [27] envisions that ‘Acid-base homeostasis should be considered as a dynamic regulation of the [H+] in a system of body fluids faced with internal and external gain and losses’, a tall order indeed for a model that does not even have a concept of the amount of acid [15,34], and cannot understand pH in a simple solution of strong ions.
Related Knowledge Centers
- Acid
- Body Fluid
- Extracellular Fluid
- Ph
- Physiology
- Protein Tertiary Structure
- Metabolism
- Homeostasis
- Cell
- Fluid Compartments