HTML Injection Attacks: Impact and Mitigation Strategies
Lecture 21
1. POTASSIUM (K+) Dominant Intracellular Electrolyte Normal level of plasma in extracellular fluids is 3.5-5.1 mEq/l
2. Potassium Function Potassium is responsible for control intracellular fluid osmolarity Maintaining resting membrane potential, nerve impulse and muscle contraction Play role in acid/base balance
3. Potassium K is filtered through glomerulus K is reabsorbed to plasma at proximal convoluted tubule (PCT) and the loop of Henle Aldosterone reabsorb Na in the plasma and secret K in the distal convoluted tubule (DCT) Mostly K excreted in the urine
4. Hypokalemia: A below level of K in the extracellular fluids of less than 3.5 mEq/l, may cause skeletal muscle weakness, respiratory arrest Hyperkalemia A high level of K in the extracellular fluid of more than 5.1 mEq/l may cause diarrhea, restlessness, muscle weakness
5. Calcium Total Ca level in the plasma 9 – 11 mEq/l Hypercalcemia: Excess of Ca in the extracellular fluid fatigue, confusion, coma, Hypocalcemia: A low concentration of Ca in the extracellular fluids of less than 9 mEq/l muscle spasm occur
6. Effect of calcitonin When Ca concentration too high. Thyroid gland releases calcitonin in the blood Calcitonin stimulate osteoblast which caused bone formation Calcitonin reduces Ca concentration
7. Effect of parathyroid hormone When Ca concentration too low parathyroid gland releases parathyroid hormone PTH increases the activity of osteoclast which increases the Ca concentration in the plasma Parathyroid hormone increase the uptake of Ca from the filtrate in the kidney into the plasma
8. Acid/Base Balance Homeostasis of hydrogen ion content Body fluids are classified as either acids or bases depending on H ion concentration Acid is an H donor and elevates the hydrogen ion content of the solution to which it is added Base is an H acceptor and can bind hydrogen ions Measure the acidity and alkalinity of a solution in units of pH, which is the measurement of free H ion in solution Normal pH of blood is 7.35-7.45 (alkaline)
9. Acids During the process of cellular metabolism acids are continually being formed and excess hydrogen ions must be eliminated There are two types of acids formed: volatile acids are excreted by the lungs and nonvolatile acids are excreted by the kidney Volatile acids can be excreted from the body as gas. Carbonic acid produced by the hydration of carbon dioxide is a volatile acid Normally carbon dioxide is excreted by the lungs as fast as metabolism produces it, so carbonic acid is not allowed to accumulate and alter pH
13. Regulation of pH Three methods control pH 1. chemical buffers-when Hydrogen is removed a buffer replaces it 2. regulation of carbon dioxide by respiratory system 3. regulation of plasma bicarbonate concentration by the kidneys-slower, second line of defense
14. Chemical buffers These are the first line of defense against changes in pH Act within a fraction of a second for immediate defense against H+ shift Buffers are composed of weak acid and weak base pairs Convert strong acids into weak acids and strong bases into weak bases
15. Chemical Buffer System H2CO3/HCO3 buffer system H2PO4/HPO4 buffer system Proteins buffer
16. Chemical Buffers Carbonic acid-bicarbonate system is most important extracellular buffer because it can be regulated by both lungs and kidneys Carbonic acid/bicarbonate ratio is usually 1:20 Phosphates act as a buffer like the bicarbonate system does and protein buffers are the most abundant buffers in body cells and blood
17. Regulation of pH through respiratory system Decreases respiration rate causes Increase CO2 in the plasma Less CO2 is exhaled Results in hypoventilation Accumulate CO2 results in increase H2CO3 and H concentration pH decreases
18. Renal control of pH If acid increases kidney regulate pH by: Re-absorption of bicarbonate in proximal convoluted tubule Generate bicarbonate in the renal tubule Secreting H ions. In urine, hydrogen ion is buffered by phosphate and ammonia If the pH is high, bicarbonate is not re-absorbed in the renal tubule and eliminated pH decreases
