Excretion (the kidney) q's Flashcards
(63 cards)
a student designed an experiment to investigate the effect of temp on the rate of glucose diffusion through dialysis tubing. State factors that would need to be controlled in this experiment
- vol of solution
- initial glucose conc
- brand of dialysis tubing
- length of dialysis tubing
describe the structural difference between alpha and beta glucose molecules
H above the ring / OH below ring on carbon 1
what can you conclude about the likley effect of sulthiame (inhibits carbonic anhydrase) on the reabsorption of sodium ions in the PCT?
- fewer H+ ions in PCT cells
- No cotransport of Na+ ions into cells
- no active transport of Na+ ions into the blood
compare the processes occuring in the proximal and distal convoluated tubules
similarities
- both use active transport
- both involve co transport
- both involve selective reabsorption
- both involve use of Na+
differences
- DCT involves use of Ca2+
- co transport in DCT involves ions only
- PCT involves ions+ moleucles
state+ explain one symptom you would expect to oberserve as a result of nephrogenic diabetets insipidus (Li entering Na Channels ; prevent cells from responding to collecting duct)
- high level of urine/ always thirsty
- fewer aquaporins in the plasma membrane of CT
explain why podocytes are usually unable to undergo mitosis
- are differenciated therefore cannot divide
- are in G0 phase of cell cycle/ resting phase
- shape is too irregular therefore cannot divide
- cytoskeleton cannot function
- if mitosis occured, it would alter no. of fenestrations
- it would alter an aspect of ultrafiltration
what features of adult stem cells can make them suitable for regeneration of tissues in the kidney?
- adult stem cells are multipotent
- differenciate to became any cell type within kidney
similarities between ultrafiltration and formation of tissue fluid
- small molecules diffuse out of the blood
- both processes occurs in capillaries
- large molecules (proteins/rbc) remain in blood
- high hydrostatic pressure in both
- many molecules (water etc) reabsorbed back into capillaries
- blood vessels become narrower to maintain hydrostatic pressure
- hydrostatic pressure greater than oncotic pressure in both
- lymphocytes can pass through in both
- both involves basement membrane
differences between ultrafiltration and the formation of tissue fluid
- filterate enters the bowmans capsule + then PCT in the kidney but tissue fluid bathes cells
- molecules that are not reabsorbed by capillaries form urine in the kidney but molecules that are not reabsorbed from tissue fluid will form lymph
- blood filtered through 3 layers in ultrafiltration by only 1 layer in formation of tissue
- knot of capillaries in ultrafiltration but a network of capillaries in formation of tissue fluid
suggest+ explain 2 characteristics of a patient that must be taken into account when using this GFR measurement to diagnose kidney damage
- age bc kidney finction declines w/ age
- gender bc men+ women have diff muscle mass
explain why the presence of protein albumin in the urine indicates kidney damage
- large protein should remain in the blood
- protein too large to cross the basement membrane
state one function of the distal convoluted tubule
regulation of ions
describe the function of the structures labelled A (something in PCT)
increase SA for reabsorption
has cotransporters for active transport of Na+
suggest why DCT lumen had high conc of urea
water is removed earlier in the nephron
explain why some foods affect urine production (bar chart)
- salted crisps+ boiled sweers reduce WP bc of high sugar content
- osmoreceptors in hypothalamus detetct change in WP in blood + cause increased release of ADH
- ADH causes production of aquaporins in collecting duct so more water reabsorbed into capillaries
- bread/milk/choco incre WP of blood
- causes reduced ADH release
describe how the endocrine + nervous system work together to increase water reabsorption from the collecting duct (endocrine system)
-hypothalamus causes release of ADH from pituitary aldosterone released from adrenal cortex
- ADH released from pituitary gland
-ADH binds to receptors of the cell membranes of collecting duct cells+ incr permeability to water (regulated by aquaporins)
- role of cAMP
describe how the endocrine+ NS work together to incr water absorption from the CT (NS)
- Hypothalamus is part of NS
- osmoreceptors in the hypothalamus
- detect a low WP in the blood
- ADH prodcues in the hypothalamus
- posterior pituitary is extension of hypothalamus
decribe how endocrine + NS work together to incr water absorption from the collecting duct (aldosterone)
- sodium ions pumped out of collecting duct cells into tissue fluid + K+ ions pumped in
- decr WP in tissue fluid
- conc grad established
- Na+ reabsorbed from the collecting duct lumen
- H20 diffuses into CT via osmosis
reason why a diuretic (drug) might be most effective at reducing a persons BP
more urine is produced
reason why a diuretic (drug) would be the most appropriate for use by a person w/ type 2 diabetes
one that does not have an affect on glucose
suggest two adv and one dis of a kidney transplant compared to dialysis
adv- doesnt require repeated dialysis ; better quality of life
dis- risks of surgery ; difficult to find organ donor
suggest a non invasive method that could be used to test for these cancers (bladder/kidney)
test urine
explain why the visible blood vessels are likely to be veins
- have valves so will bulge
- large lumen as contains large volumes of blood
- found closer to the surface skin than arteries
suggest why anabolic steriods are effective when applied to the surface of the skin
- skin has large SA for absorption
- skin has many capillaries
- steriods are lipid soluble so can cross phospholipid bilayer
- muscles are close to the skin surface so short diffusion distance