Homeostasis Of Fluid Balance Flashcards

Question

Distal Tubule and Collecting duct of nephron

Answer 1

K+ and H+ not always permeable to H2O, but hormonal reg can change this High blood volume leads to increased blood pressure Inhibit ADH – decreasing water reabsorption Inhibit renin and aldosterone and increased ANH - decreases Na+ reabsorption Vasodilation of renal arteries increasing filtration – more water lost in filtrate When ADH is present reabsorption of H2O through wall of distal tubule and collecting duct Overall reduction in blood volume through greater water and Na+ loss in urine

Answer 2

Imp. When theres a drop in DP 1.renin 2.angiotensin 2 3.aldosterone 1.When BP is decreased, kidneys detect and increase renin secretion into circulatory. Results:vasoconstriction Increase H2O reabsorption, decrease urine formation 2.Renin travels through blood and acts on angiotensin to make angiotensis 1 3. enzyme: angiotensin converting enzyme acts on angiotensin 1 to convert it to its a tive for, angliotensin 2 4.angiotensin 2 is a vasoconstrictor—increases blood pressure 5.angiotensin 2 acts on adrenal cortex to increase secretion of aldosterone 6.aldosterone acts on kidneys, causing them to conserve Na+ and H2O— water volume lost from blood into urine is reduced— less fluid loss so blood volume is maintained—adequate BV is essential to maintain normal venous return to heart and maintain BP

Answer 3

Stimulus—receptors and control centers; Pituitary—baroreceptors inhibit posterior pituitary ADH secretion when blood volume increases. Kidney—juxtaglomerular apparalli inhibit renin release when blood volume increases, which decreases aldosterone secretion. Heart—atrial cardiac muscle cells secrete ANH when blood volume increases. Blood vessels—sympathetic division barocepters detect increased blood volume, which causes vasodialation of renal arteries Response—effectors; Decreased ADH decreases water reabsorption by the distal convoluted tubules and collecting ducts. Less water returns to the blood and more water is lost in the urine, which decreases blood volume . Decreased aldosterone and increased ANH decrease Na+ reabsorption from the distal convoluted tubule and collecting duct. More Na+ and water are lost in the urine, which decreases blood volume. Increased renal blood flow increases the rate of filtrate formation, and more water is lost in the urine Homeostasis restored—reduced blood volume due to loss of water and Na+ in the urine lowers blood pressure

Answer 4

To increase urine process Anti this would be to decrease ADH Secreted by posterior pituitary neurons when solute concentration of blood or interstitial fluid increases or blood pressure falls promotes H2O conservation Increases permeability of collecting duct cells to water by opening water pores and adding them More water reabsorbed Lower volume of more concentrated urine secretion regulated by changes In BP baroreceptors monitor BP detect significant decrease, ADH secretion increases and vise versa

Answer 5

Evaporation from skin—sweat, exercise; increases in hot environment to maintain core temperature— even more in dry environment Exhalation of warmed and moistened air—we do this when the air comes in—increases in a dry environment as air taken in has less moisture—not much with each breath, but sum all the breaths Excretion in Urine—Modified based on hydration status, impacting blood pressure and blood solute concentrations Loss in feces Intake required to balance losses—You should be able to maintain your body fluid volume very consistently Take in more water if you exercise, especially if in heat for prolonged periods. Keep in mind water from fruits and vegetables constitutes as they have a high-water content

Answer 6

Weren’t initially filtered Movement of non-filtered substances from the blood into the filtrate. Active or passive movement of toxic by-products from metabolism (ammonia), drugs and other molecules Certain tubule cells transport additional solutes from blood into filtrate Potassium, bicarbonate and proton (pH) levels in the blood can be regulated through modification of tubular secretion through hormonal control mechanisms

Answer 7

Stimulus—receptors and control centers; Buffers—buffers bind H+.H2O +CO2 <-H2CO3<-H+HCO3. Lungs—the respiratory control center in the brain increases the rate and depth of respiration, which decreases blood flow. Kidney—the distal convoluted tubules increase H+ secretion into the urine, and increase HCO3 reabsorption into the blood. getting rid of more protons, keeping bicarbonate Response—effectors; The number of H+ in the blood decreases.—bring PH up Decreased blood CO2 causes H+ to react with HCO3 to form carbonic acid, which decreases H+ in the blood H2O+CO2 <-H2CO3 <-H+ + HCO3- More H+ are removed from the blood and more HCO3- are available to bind H+

Answer 8

Stimulus—receptors and control centers; Kidney—The distal convoluted tubules decrease H+ secretion into the urine and decrease HCO3-reabsorption into the blood. Lungs—The respiratory control center in the brain decreases the rate and depth of respiration, which increases blood CO2 Buffers—buffers release H+ H2O + CO2 ->H2CO3 ->H+ + HCO3- Response—effectors; Fewer H* are removed from the blood, and fewer HCO3- are available to bind H+ Increased blood CO2 reacts with water to produce carbonic acid, which dissociates to increase H+ H2O+ CO2 —> H2CO3 >H+ + HCO3- The number of H* in the blood increases. Homeostasis restored—blood PH decreases(H+ increases)