Nephron Structure Flashcards
Name the blood vessels related to the nephron structure
Afferent Arteriole, Efferent Arteriole and Glomerulus
Name the 5 main sections of the nephron in the chronological order
Bowmans/ Renal Capsule Proximal Convoluted Tubule Loop of Henle Distal Convoluted Tubule Collecting duct
Name the 4 parts to osmoregulation
Ultrafiltration + formation of glomerular filtrate
Reabsorption of glucose and water by the PCT
Maintenance of the Na+ gradient in the medulla by the Loop of Henle
Reabsorption of H20 by the DCT and Collecting duct
Name the vessels that the blood passes through in and out of the nephron
Renal Artery, afferent arteriole, glomerular capillaries, efferent arteriole, capillaries, renal vein.
Describe how Ultrafiltration occurs
Walls of the glomerular capillaries are eplithal with pores
Diameter of afferent > efferent so HP builds up in Glomerulus
H20, glucose and mineral ions are squeezed out of the capillary to form glomerular filtrate.
Blood cells and proteins are too large to pass through
Name the 5 ways the movement of the glomerular filtrate is resisted
Capillary epithelial cells Connective tissue and epithelial cells of the blood capillary Epithelial cells of the renal capsule HP of the fluid in renal capsule space low wp of the blood into the glomerulus.
What 2 modifications are in the Bowman’s Capsule?
Podocytes = specialised cells which have space between
Endothelium of glomerular capillaries have spaces
How is the Epithelial cell modified to reabsorb H20 and glucose in the PCT
microvilli to reabsorb substances from the filtrate
infoldings at their base to give a large SA
high density of mitochondria to prove ATP
Describe the process how the PCT reabsorbs h20 and glucose
na+ are AT out of the PCT into the blood capillary
Now Na+ can facilitated diffuse from lumen of PCT into epithelial lining
When they diffuse in glucose/H20 is co-transported in please
Describe the differences between the descending ascending limb of the loop of Henle
Descending Limb= narrow thin walls that are permeable to H20.
Ascending limb= wide, thick walls that are impermeable to h20
The concentration of urine is related to what?
the length of the loop of henle
Describe the counter current multiplier of the Loop of Henle
Na+ out of the ascending limb of loop of Henle using ATP from mitochondria in the walls
This creates a low wp in the medulla interstitial region but ascending limb impermeable to H20 so H20 passes out of filtreates via osmosis in the descending limb to a capillary and carried
Filtrate loses H20 down the descending limb hence wp lowers- lowest at the tip.
ascending limb Na+ diffuse out as it moves up a limb so wp increases
Interstitial space have wp gradient down
CD permeable to H20 so water moves via osmosis
Explain how the Distal Convoluted Tubule is adapted
microvilli to increase rate of absorption
Mitochondria to generate ATP for AT
Describe and explain how the secretion of ADH affects urine produced by the kidneys when the water potential of the blood is low?
1) Permeability of (membrane/cells) to water is increased
2) More water absorbed (from/leaves) distal tubule/ collecting duct
3) Smaller volume of urine
4) Urine becomes more concentrated
Explain the role of ADH in the production of concentrated urine?
1) When water potential of the blood is too low
2) Detected by receptors in the hypothalamus
3) Pituitary secretes (releases) more ADH
4) ADH increases permeability of aquaporins (opens channels for water in DCT)
5) More water is reabsorbed; leaves nephron and moves into the blood
6) By osmosis down the water potential gradient
