Examples of pH in the following topics:
-
- Acid-base imbalances in blood pH can be altered by changes in breathing to expel more CO2, which will raise pH back to normal.
- Since maintaining normal pH is vital for life, and since the lungs play a critical role in maintaining normal pH, smokers have yet another reason to quit smoking.
- Acid–base imbalance occurs when a significant insult causes the blood pH to shift out of the normal range (7.35 to 7.45).
- When blood pH drops too low (acidemia), the body compensates by increasing breathing thereby expelling CO2, shifting the above reaction to the left such that less hydrogen ions are free; thus the pH will rise back to normal.
- When blood pH drops too low, the body compensates by increasing breathing to expel more carbon dioxide.
-
- Chemical buffers such as bicarbonate and ammonia help keep blood pH in the narrow range compatible with life.
- The body is very sensitive to its pH level, so strong mechanisms exist to maintain it.
- Its pH changes very little when a small amount of strong acid or base is added to it.
- Many life forms thrive only in a relatively small pH range so they utilize a buffer solution to maintain a constant pH.
- Several buffering agents that reversibly bind hydrogen ions and impede any change in pH exist.
-
- Alkalosis is the increased alkalinity of blood and other tissues, generally occurring when the blood pH is above 7.45.
- Generally, alkalosis is said to occur when pH of the blood exceeds 7.45.
- The opposite condition is acidosis (when pH falls below 7.35).
- Metabolic alkalosis is a metabolic condition in which the pH of tissue is elevated beyond the normal range (7.35-7.45 ).
- As the pH of blood increases, the protein in the blood becomes more ionized into anions.
-
- In the fetus, the normal range differs based on which umbilical vessel is sampled (umbilical vein pH is normally 7.25 to 7.45; umbilical artery pH is normally 7.18 to 7.38).
- Acidosis refers to a low pH in tissue.
- Acidemia refers to a low pH in the blood.
- Alkalosis refers to a high pH in tissue.
- Alkalemia refers to a high pH in the blood.
-
- In the fetus, the normal range differs based on which umbilical vessel is sampled (umbilical vein pH is normally 7.25 to 7.45; umbilical artery pH is normally 7.18 to 7.38).
- Acidosis refers to a low pH in tissue.
- Acidemia refers to a low pH in the blood.
- Alkalosis refers to a high pH in tissue.
- Alkalemia refers to a high pH in the blood.
-
- The goal of this system is to keep the pH of the blood stream within normal neutral ranges, around 7.35.
- The respiratory chemoreceptors work by sensing the pH of their environment through the concentration of hydrogen ions.
- Central
chemoreceptors: These are located on the ventrolateral surface of medulla
oblongata and detect changes in the pH of spinal fluid.
- As bicarbonate levels decrease while hydrogen ion concentrations stays the same, blood pH will decrease (as bicarbonate is a buffer) and become more acidic.
- The chemoreceptors are the sensors for blood pH, the medulla and pons
form the integrating center, and the respiratory muscles are the
effector.
-
- Blood flow is regulated locally in the arterioles and capillaries using smooth muscle contraction, hormones, oxygen, and changes in pH.
- Local responses to stretch, carbon dioxide, pH, and oxygen also influence smooth muscle tone and thus vasoconstriction and vasodilation.
- Generally, stretch and high oxygen tension increase tone, and carbon dioxide and low pH promote vasodilation.
- Brain arterioles are particularly sensitive to pH, with reduced pH promoting vasodilation.
-
- Acidosis describes increased acidity in the blood and other tissues, usually measured as arterial pH below 7.35.
- Acidosis is said to occur when arterial pH falls below 7.35, while its counterpart (alkalosis) occurs at a pH over 7.45.
- In humans, the normal pH of arterial blood lies between 7.35 and 7.45.
- Blood pH values compatible with life in all mammals are limited to a pH range between 6.8 and 7.8.
- The Henderson-Hasselbalch equation is useful for calculating blood pH, because blood is a buffer solution.
-
- Ingested food stimulates gastric activity in two ways: by stretching the stomach and by raising the pH of its contents.
- Small peptides also buffer stomach acid so the pH does not fall excessively low.
- But as digestion continues and these peptides are emptied from the stomach, the pH drops lower and lower.
- Below pH of two, stomach acid inhibits the parietal cells and G cells: a negative feedback loop that winds down the gastric phase as the need for pepsin and HCl declines.
-
- Outside the range, pH becomes incompatible with life; proteins are denatured and digested, enzymes lose their ability to function, and the body is unable to sustain itself.
- To maintain this narrow range of pH the body has a powerful buffering system.
- The kidneys also play an important role in maintaining acid-base homeostasis by regulating the pH of the blood plasma.
- The kidneys are slower to compensate than the lungs, but renal physiology has several powerful mechanisms to control pH by the excretion of excess acid or base.