Nephron + Kidney + Urine Flashcards
(22 cards)
What changes occur in body that lead to production of concentrated urine (5)
- hypothalamus detects high (salt) concentration of blood
- pituitary gland releases ADH
- increasing permeability (of) …
- collecting duct …
- (so) more water reabsorbed (into blood)
Role of nephron in osmoregulation
- as blood concentration increases
- hypothalamus detects change
- and sends signals to pituitary gland
- which releases ADH
- ADH increases permeability of collecting duct
- so more water reabsorbed back into blood from collecting duct
- more concentrated urine
- blood water concentration increases
- blood (salt) concentration decreases
- hypothalamus no longer simulated
- so less / no ADH released by pituitary gland
Nephron structures in order
- glomerulus (outside nephron)
- bowman’s capsule
- proximal convoluted tubule
- loop of henle
- distal convoluted tubule
- collecting duct
What is glomerulus
- network of capillaries
- where ultrafiltration occurs
- high pressure of blood forces water, glucose, urea, salts to be filtered out of blood and into nephron (bowman’s capsule)
What does bowman’s capsule do
- site of entry (to nephron) of filtrate substances
- like water, urea, salts, glucose
What does proximal convoluted tubule do
- selective reabsorption
- ALL glucose is reabsorbed
- SOME salts reabsorbed
- SOME water reabsorbed
What is reabsorbed in PCT
- ALL glucose
- SOME water
- SOME salts
What is reabsorbed in loop of henle
- SOME water
- SOME salts
What is reabsorbed in DCT
- SOME salts
- SOME waste
- regulates salt levels + pH
What does DCT do
- regulates:
- pH
- salt levels
What does collecting duct reabsorb
- water
- how much is dependent on ADH levels
What is the permeability of collecting duct controlled by
ADH levels
What does urine contain
- urea
- excess water
- excess salts
Route of urine after collecting duct
- collecting duct
- renal pelvis
- ureter
- (urinary) bladder
- urethra
- penis / vaginal opening
Define osmoregulation
- maintenance of water + salt levels of the body
What part of the kidney is the nephron located in
- in the cortex
Why is no ADH release dangerous
- osmoregulation
- collection duct…
- is less permeable
- less water reabsorbed / less water in blood / dehydration
- more urine
Why is glucose reabsorbed in nephron
- (so that) glucose isn’t excreted / lost from the body
- maintain blood glucose…
- (as it is) required for respiration (for energy)
Effect on urine production of high protein + salt
- blood concentration increases
- hypothalamus detects change
- (pituitary gland) secretes (more) ADH
- increasing the permeability of collecting duct
- more water is reabsorbed / more concentrated urine
- more urea produced
- less urea reabsorbed
- more salts in plasma
- so less salts reabsorbed
- more glucose in blood (but no change since all is reabsorbed)
How structure of glomerulus is adapted to move glucose into blood
- capillary entering is wider
- increased pressure
- for ultrafiltration
How is glucose reabsorbed back into the blood
- active transport
- low to high concentration/ against concentration gradient
- using energy / ATP
Why does glucose need to be reabsorbed
- respiration
- to make energy / ATP
