L17 Flashcards
what does Asparagus contain that makes you pee smell bad
Asparagus contains sulfur compounds called mercaptan.
you need to have a gene to produce an enzyme to brake down mercaptan into its sulfur bioproducts to get the unpleasant smell
what are the 3 basic processes of the nephron
- glomerular filtration
- tubular secretion
- tubular reabsorption
Glomerular filtration, tubular secretion and reabsorption
are energy intensive processes, so why do we do this?
although it seems wasteful to filter large amounts of substances from the plasma only to reabsorb most back
again, this allows the body to quickly rid
the body of toxic or harmful substances from the blood
therefore it has to do with renal clearance
what is Tubular Reabsorption
As the filtrate passes down the tubule, most is reabsorbed back into the blood (plasma) (filtrate to blood)
how is Tubular Reabsorption achieved
• This is achieved through action of specific channels and
transporters in the membranes of the epithelial cells of the
tubule, and through the tight junctions of some of the segments of the nephron.
what kind of epithelium does the Proximal tubule contain
Leaky absorptive epithelium
what kind of solution is the Proximal tubule responsible for producing
• Isosmotic solution
what kind of epithelium do the Late Distal tubule and Collecting duct contain
• Tight absorptive epithelia
what kind of solution do the Late Distal tubule and Collecting duct produce
• Hyperosmotic solution
what part of the nephron is under hormonal control
Late Distal tubule and Collecting duct
different parts of the nephron have different roles. what is this dependent on
What the different parts of the nephrons are doing is dependent on the polarity of the cells and what transport proteins are on the apical and basolateral membranes
where is SGLT1 and SGLT2 located in the nephron
SGLT1 in the straight tubules and SGLT2 in the proximal tubule
what amount of water is filtered per day
180L
what amount of water is excreted per day
1.8L
what % of water is reabsorbed per day
99%
what causes Diabetes mellitus
- too much glucose
where are substances secreted from in the nephron
Substances can be secreted from the peritubular capillaries (peritubular blood to the filtrate)
note peritubular capillaries = first part of the nephron (before the loop of henle) - secretion
vasa recta = loop of henle - absorption
what is the difference between glomerular filtration, tubular secretion
Like glomerular filtration, tubular secretion constitutes a
pathway of moving substances from the blood to the
tubule lumen
Secretion at peritubular capillaries enables disposal of substances at a higher rate than depending on filtration
alone
what things would be secreted from the body
• H+, K+, penicillin, metabolites from pesticides and many
substances
what is metabolic acidosis
is when the body has too much H+
why do we secrete K+
because we have a lot of it in our diet
Which of the following statements is TRUE?
A. 100% of the filtered urea is reabsorbed by the nephron.
B. Reabsorption is the only renal process that ‘recovers’ filtered substances and water.
C. Secretion is not an energy intensive process.
D. Normally, 95% of the filtered glucose is reabsorbed by your kidneys, unless you are a diabetic.
B
what is Glomerular Filtration Rate (GFR)
• Amount of filtrate produced per unit of time
what is the normal value for Glomerular Filtration Rate (GFR)
Normal value = 125 ml / min (180 L / day)
Equal to sum of filtration rate of all functioning nephrons in the two kidneys
