Uric acid formation and excretion in birds The metabolic end product of protein and amino acids in reptiles and birds is the uric acid (instead of urea in mammals). Uric acid is formed in liver and also in kidneys from ammonia. Uric acid is freely filterable at the glomerulus, and it is also secreted by […]
Renal portal system (RPS) in birds An unique feature of avian kidney is its Renal Portal System (RPS) which provides an extra branch of blood flow to the renal tubules along with peritubular capillaries. Venous blood from portal vein gives one branch to the kidney and this branch provides the microcapillaries which perfuse the tubules along
Excretion in birds In the birds, the ureters transport the urine to the cloaca, which is the common collection site for digestive, reproductive and urinary organs. There is no urinary bladder in birds. Urine formation in birds is almost similar to the mammals but still then there are some notable differences: Presence of two major
Electrolytes An electrolyte in any chemical that dissociates to ions when dissolved in a solution. Ions can be positively charged (cations) or negatively charged (anions). The major electrolytes found in the body are sodium, potassium, calcium, magnesium, chloride, phosphate, sulphate and bicarbonate. The primary electrolytes of the ECF are sodium, chloride and bicarbonate and in
Fluid and electrolyte balance Regulation of fluid by the body is necessary to maintain homeostasis. If the water or electrolyte equilibrium is affected, many body functions fail to proceed at normal rates. Water Water is a major constituent of all living things. Most of the ions and molecules that make up living matter have chemical
Acid Base balance disturbances The pH of the ECF is determined by the rate of conjugate base to their weak acids. The total amount of buffer base in whole blood including HCO3, Hb and other bases of lesser importance is called buffer base (B.B). These bases are known as metabolic components determining blood pH. Acid
Renal control of acid base balance The kidneys regulate acid-base balance by excreting either an acidic or basic urine. Excretion of either an acidic or a basic urine removes acids or basic from the ECF. Large numbers of HCO3– ions are filtered in the urine and if they are excreted into the urine, it removes base
Respiratory regulation of acid base balance The respiratory system acts as the second line of defense against acid base disturbances. An increase in PCO2 of ECF, decreases the pH, while a decrease in PCO2, increases the pH. Therefore, by adjusting the PCO2, the lungs effectively regulate the H+ ion concentration of the ECF. An increase in ventilation
Chemical acid base buffer systems When there is a change in the H+ ion concentration, the body fluids react immediately to minimize the change. Chemical buffers act by converting either strong acids or bases into weaker acids or bases. The various chemical buffers are- Bicarbonate This is the most important buffer system in the body. Bicarbonate
Acid base balance The normal blood pH is 7.4. Maintenance of normal blood and extracellular pH within the narrow limits is essential for homeostasis. The pH usually refers to the hydrogen ion (H+) concentration and has a widespread effect on the function of the body systems. Any disturbance in the H+ ion concentration leads to imbalance of
