Key Principles of Acids and Bases:Acids and bases are defined by their ability to donate or accept hydrogen ionsAcids are chemical substances that can donate/release, hydrogen ions in water.Bases, aka, alkalines, are chemical substances that can accept hydrogen ions.pHpH is a measure of the concentration of hydrogen ions in solutionpH scale displays the concentration of hydrogen ions from 0 – 14.An acidic solution has a pH less than 7; it has a high concentration of hydrogen ions.A neutral solution has a pH of 7.A basic solution has a pH of greater than 7; it has a lower concentration of hydrogen ions. Calculation of pH: Negative logarithmic function. pH values for human bodily fluids:Gastric juice, which is secreted by organs of the digestive system, has a pH value around 2; its acidity aids in food digestion.Saliva is slightly acidic, but much closer to neutral than are the gastric juices.For comparison, pure water has a neutral pH, 7.Arterial blood has a pH of approximately 7.4Homeostasis & BuffersBiological organisms are constantly adding acids to their bodily fluids during metabolism, but our blood is slightly basic. Intra- and extra-cellular buffers operate to maintain homeostasis.Buffers minimize changes of pH in solutions; they reversibly donate or accept hydrogen ions. Example: Bicarbonate buffer system:When hydrogen ions are added to the extracellular fluid, they combine with bicarbonate to produce carbonic acid, which is a weaker acid.If the extracellular fluid becomes too basic, the reaction can be reversed: Carbonic acid can dissociate to form hydrogen ions and bicarbonate; when pH increases (becomes more alkaline), carbonic acid dissociates to form bicarbonate, which is a base, and hydrogen ions. Clinical ConsequencesIf the body cannot maintain homeostasis due to pathology, disturbances in bodily fluid pH inhibit enzymatic reactions.Thus, failure to regulate pH causes a range of clinical symptoms associated with acidosis (too high blood acid content)...
Growth Hormone Defects & ExcessPhysiology ReviewSecretion: Growth hormone regulates growth and metabolism in most body tissues. Growth hormone releasing hormone (GHRH) is secreted from the hypothalamus, and travels via neurons to the hypothalamic-pituitary portal system to reach somatotrophs in the anterior pituitary. In response to GHRH, the somatotrophs release growth hormone into the blood. Effects: Growth hormone acts directly on the tissues to increase blood glucose and free fatty acids, and promotes tissue growth and differentiation. Furthermore, growth hormone triggers hepatic release of IGF-1, which enhances the effects of growth hormone. Growth Hormone DefectsGrowth Hormone DeficiencyGrowth hormone deficiency results in reduced levels of growth hormone and, consequently, reduced levels of IGF-1. In most cases, isolated growth hormone deficiency is due to defects in the GH1 gene, which is responsible for growth hormone production.However, we need to rule out general hypopituitarism, in which other anterior pituitary hormones are also low.Treatment: Recombinant human growth hormone. Growth Hormone Insensitivity Growth hormone insensitivity is characterized by normal or high levels of growth hormone, and low levels of IGF-1. Insensitivity is caused by growth hormone receptor defects, which may be hereditary, as in Laron Syndrome, or acquired as a result of malnutrition, liver disease, diabetes, growth hormone receptor antibodies, or other pathologies.Treatment: recombinant IGF-1. Effects of Growth Hormone Defects:In Childhood: - If the defect appears in childhood, linear growth is slow (sometimes called pituitary dwarfism); - These patients often have delayed puberty, with small gonads and genitalia (micropenis).In Adulthood: - If growth hormone defects appear later in life, adults present with body composition changes, including reduced muscle and bone mass, and increased fat mass. - These patients have increased risk of cardiovascular disease (including left...
This post from 2013 was edited, updated, and expanded in 2020. This is one out of a handful of our favorite articles on walking, including topics covering what various “walking parts” do as well as…
Adam Bennett leads the class in an exploration of the theory and application of wristlocks in self-defense and sportive martial arts.
#Physiotherapy #Therapists #RehabClinic #JHRehabilitation Preparing yourself before a session is critical, be it with your mind or clothing. Complete involvement provides quicker and faster results.
