Renal Flashcards
What cells make up the PCT?
Simple cuboidal cells with microvilli - tight junctions
What cells make up the loop of Henle?
Flattened Simple Squamous
What cells are found in the DCT?
Principle cells - respond to ADH
Intercalated Cells (I cells) - secrete H+ ions
What are volatile acids?
Acids that can be breathed off - CO2 example.
What are fixed Acids?
Acids that are a result of metabolic processes and cannot be blown off but instead need to be excreted.
What is the 1st concept to be understood in acid base balance?
That the [H+] doesn’t need to be high in order for there to be acid base disturbance. other biochemistry will be affected i.e. HCO3- will be reduced.
How does the Kidney regulate Acid base?
- Re-absorption of HCO3-
- Excretion of Fixed Acid
- In the process of H+ excretion there is new synthesis of HCO3-
During re absorption of HCO3- is there a net loss of H+ or CHO3-?
No there is no net gain or loss. it is equal.
Why is the PCT so good at reabsorbing?
Specialised cellular characteristics:
- large no. of mitochondria
- Brush border for high surface area
- enzymes needed break down of certain substance s
- co-transporters etc.
What cells reabsorb sodium and secrete K+?
Principle cells
Where is K+ and H+ secreted?
DCT and Cortical collecting duct.
Where is most of the Bicarbonate reabsorbed?
PCT - 80-90%
What cell secretes H+ in the presence of aldosterone?
Intercalated cell
Where is the primary place of H+ secretion? What is the flaw in this?
PCT is where the majority of the H ions are secreted however, the majority are reabsorbed.
therefore the PCT does not contribute greatly to hydrogen ion loss.
Why is NH4+ the most important vehicle for H+ excretion?
Because it can be up regulated when needs be