Myogenic Mechanism
Renal blood flow autoregulation is an essential homeostatic chemical change that defends the kidney from a delegate in arterial pressure that would be sent to the glomerular capillaries and drive injuries. Two mechanisms impart to renal autoregulation that is, the myogenic, which responds very fast, and the tubuloglomerular feedback (TGF), which is slow in response. Myogenic mechanisms help maintain an invariant blood flow at varied pressure in the artery arterial and protect against renal damage from overpressure.
The myogenic reaction is defined by a decrease of the diameter of the vessels in response to the various alteration in the Transmural force and plays an essential function in maintaining the ambient vascular tone and the autoregulation of blood flow of the resistivity vasculature. Myogenic mechanisms are also inbuilt to the smooth muscle blood tubes, particularly in small blood vessels and arterioles (Jackson, 2021). If the force inside a particular vessel is abruptly enlarged, the vessel responds by narrowing, while vasodilation and relaxation are caused by minimized pressure within the vessel.
Tubuloglomerular Mechanism
On the other hand, the tubuloglomerular mechanism is an accommodative execution that links the rate of glomerular action to the compactness of salt in the tubule liquid at the macula lutea. Tubuloglomerular feedback is designed to regulate the amount of salt entering the lateral nephron. A high sodium chloride(salts) distribution and the resorption rate at this site drive contraction of the corticipetal arteriole, a diminution in glomerular filtration pace (GFR), and a decrease in renal blood flow.
This auto regulatory mechanism is built-in to the kidney in that it does not necessitate neuronal or humoral factors. The process of tubuloglomerular response acts as counter feedback regulation mechanism which makes use of the information concerning distal tubular fluid flow rate to control the nephritic blood flow and since the Renal Blood Flow affects the glomerular infiltration rate, and thus the proximal fluid flow value rate, the tubuloglomerular feedback helps hold a comparatively unfluctuating value of renal blood flow and glomerular filtration rate. Tubular secretion is the passage of matter like drugs and creatinine from the blood system into the peritubular capillaries to the renal tubule in the lumen of the kidney.
Purpose
The main aim of tubular secretion is to reduce liquid waste in the blood. It is also crucial in eradicating poisons, toxins, drugs, and other natural elements found in the blood in their excess. Some of the natural elements include potassium ion, hydrogen ion, ammonia, and urea. The removed substances combine with water to form urine which flows into the bladder through the ureter. The secreted products are usually in small quantities and are generally wasted.
Processes
Two main processes are involved in tubular secretion: passive dispersion and active conveyance. Passive diffusion is the conveyance of particles from the peritubular tubules to the interstitial fluid within the nephron, while active transport involves the movement of the molecules from the renal epithelium tubule into the cavum of the nephron. Tubular secretion is usually in the last process of urine formation, known as filtration. The first step in urine formation is known as filtration.
During filtration, blood gets into the kidney through the receptive arteriole into the glomerulus. The glomerulus is surrounded by the bowman’s capsule, which filters blood cells and serum albumins, which flow out through the efferent arteriole, while the rest flow into the glomerulus as glomerulus filtrate. The subsequent process is reabsorption, in which salt ions, minerals and water are reabsorbed into the system. It happens between the distal coiled tubes, the loop of Henle, and the distal tangled tubules. The products after secretion combine with the water and salts that have not been reabsorbed to form urine which collects into the ureters, which leads to the bladder.
Mechanism and Action of Diuretics
There are three main types of diuretics, but they are five in general. The five types are thiazide and thiazide-like diuretics, loop diuretics, carbonic anhydrase inhibitors, potassium-sparing diuretics and osmotic diuretics. Diuretics may treat congestive heart failure, liver disease, hypertension, edema, and raised intracranial pressure.
Loop Diuretics
They include bumetanide and frusemide and are the most powerful diuretic drug. They act on the loop of the Henle section of the urinary organ nephrons. They effectively relieve pulmonary edema due to left ventricular heart failure, giving a quick antidote to breathlessness when administered on time. They block the chloride pump preventing the absorption of sodium and chloride ions, creating a diffusion gradient.
Thiazide Diuretics
Thiazides are absorbed from the digestive tract and act immediately between one and three hours after intake. They include discarding and aquatints; their mode of action decreases the measure of salt and water in the body. It’s also responsible for the widening of blood vessels to decrease blood pressure.
Potassium-Sparing Diuretics
They include drugs like amiloride and spironolactone and express their action on the tube portion of the tubule. Though not as competent as the loop diuretics, but are used for patients on digoxin or taking anti-arrhythmia medication. They help decrease the high glucose and uric acid levels caused by thiazide diuretic medical care.
Her diet may be restrained because salt increases the blood pressure, which undoes the action of thiazide diuretic therapy. Salt is also a risk factor for heart attacks, cardiac arrest, and chronic kidney diseases.
Regulation of Body Sodium Content
Body sodium content is regulated by the hormone aldosterone produced by the adrenal glands. Aldosterone hormone controls when the kidney will retent the sodium or when it will into the urine. Some excess sodium is also excreted in the sweat through the skin. Sodium should be regulated constantly, as excess salts cause high blood pressure. Rapidly low sodium levels of sodium may lead to hyponatremia, leading to brain swelling, headaches, and constant nausea.
Regulation of ECF Volume
Since the ECF (extracellular fluid) has to be regulated in narrow margins, the kidneys work to regulate the volume and osmolality of the ECF. This is achieved by altering the amounts of sodium and water excreted by altering absorption. Low ECF volumes between five to rent percent lead to orthostatic tachycardia.
Regulation of Blood Pressure
Blood pressure is contained by the autonomic nervous system (ANS), which increases when low and lowers when high, though short. When the blood pressure increases, the baroreceptor activity also increases. This leads to an increment in the number of afferent heartbeats towards the cardiovascular Centre. This leads to a decrease in cardiac output and vasodilation, and blood pressure. The vice versa also happens in low blood pressure.
- Problem 1: pH = 7.63, PCO219 mm Hg, HCO3– 19.5 mEq/L
- Problem 2: pH = 7.22, PCO2 30 mm Hg, HCO3- 12.0 mEq/L
For question one, the Imbalance is alkalosis since the blood pH ranges from 7.35-7.75. The cause is likely to be metabolic since it’s far from the optimum 35-45. The situation is not being compensated as the values are too close to the normal range. The described situation may occur due to health issues such as hypokalemia and low potassium. For problem two, the Imbalance is acidosis since the blood pH ranges from 7.35-7.75. The cause is likely to be respiratory since it’s close to the optimum 35-45. The situation is not being compensated as the values are too close to the normal range. The described situation may occur due to health issues such as hypokalemia and low potassium.
Reference
Jackson, W. (2021). The myogenic tone in peripheral resistance arteries and arterioles: The pressure is on!Frontiers in Physiology, 12. Web.