Week 9- Genitourinary System Flashcards
On an average day what is salt and water consumption like?
More than we need so that excess must be excreted
What is the function of the kidney?
Excretion of metabolic products, foreign substances
Regulation of body fluids, electrolytes and acid base balance
Control of blood pressure
Secrete hormones
What is the function of the detrusor muscle?
Contracts to build up pressure in the bladder to support urination
What is the function of the trigone?
Stretching of this region to its limit signals to the brain about the need for urination
Describe the flow through a nephron
Glomerulus, bowmans capsule, proximal convoluted tubule, loop of henle, distal convoluted tubule, collecting duct
At the proximal convoluted tubule where does water flow and why?
Out of the tubule because sodium and proteins are pumped out so water follows
What is special about primary and distal convoluted tubule epithelial cells?
They have a lot of mitochondria
What is special about ascending loop of henle epithelial cells?
They have few mitochondria
What are the 2 cell types in the collecting duct and how do they differ?
Principal cells- low mitochondrial density
Intercalated cells- rich in mitochondria
What are the 2 types of nephron?
Superficial and juxtamedullary
What type of nephron is more abundant and by how much?
Superficial- 10 times as many
What makes up the juxtaglomerular apparatus?
Macula densa (distal convoluted tubules) Extraglomerular mesangial cells Juxtaglomerular cells (afferent arterioles)
What is the function of the juxtaglomerular apparatus?
GFR regulation through tubulo-glomerular feedback mechanism
Renin secretion for regulating blood pressure
Is glomerular filtration active or passive?
Passive
How permeable are glomerular capillaries?
Semi permeable
Where does glomerular filtrate go through to?
Bowmans capsule
How is net ultrafiltration pressure calculated?
Hydrostatic pressure in glomerular capillaries - hydro pressure in bowmans capsule - oncotic pressure of plasma proteins in glomerular capsule
What is glomerular filtration rate (GFR)?
The amount of fluid filtered from the glomeruli into the Bowmans capsule per unit time
What is the unit for GFR?
mL/min
How is GFR calculated?
Sum of filtration rate of all functioning nephrons
Pressure of ultrafiltration x ultrafiltration coefficient (membrane permeability and surface area available for filtration)
Describe the myogenic mechanism of regulation of GFR?
Arterial pressure increases, afferent arteriole stretches, arteriole contracts, vessel resistance rises, blood flow reduces, GFR stays the same
What is renal clearance?
The number of litres of plasma that are completely cleared of substance per unit time
How is renal clearance calculated?
(conc of substance in urine x rate at which urine is produced)/ conc of substance in plasma
What are the units of renal clearance?
mL/min
why is liv such a legend?
who knows? theories are still being thought up- maybe it’s her biochemistry, the very molecules she is made from? more likely its the fact she is an anomaly and has the love of her one and only wifey xox
Describe renal blood supply through the kidney
renal artery segmental artery interlobar artery arcuate artery interlobular artery afferent arteriole glomerular capillary efferent arteriole peritubular capillary interlobular vein arcuate vein interlobar vein renal vein