Genourinary system Flashcards
What is the outer region of the kidney?
The cortex
What is the inner region of the kidney?
Renal medulla
What is located within the renal medulla?
Renal pyramids separated by renal columns
What does a renal pyramid produce?
Urine
Where does the urine from the renal pyramid terminate into?
Renal papilla
The Renal papilla drains urine into what?
Minor calyx
Multiple minor calyces drain into what?
Major calyx
What do major calyces drain into?
Ureter
What are the 3 main functions of the kidney?
1) Excretion: Excretion of metabolic products; urea; uric acid and creatine
2) Regulation: Regulate concentrations of electrolytes, acid-base balance and body fluids. Regulation of calcium absorption through the hydroxylation of 25-hydrocholecaliceferol into 1,25dihydroxycholecalicferol via 1-alpha hydroxyls, regulates erythropoesis
3) Blood pressure
How is blood pressure regulated by the kidney?
Function to control blood pressure through the production of renin by the juxta-glomeruluar cells
Which hormone secreted by the kidney regulates erythropoiesis?
Erythropoetin
Which enzyme catalyses the secondary hydroxylation of vitamin d?
1-alpha-hydroxylase
which artery does the afferent arteriole arise from?
Interlobular artery
Which artery does the glomerular capillaries arise from?
Afferent arteriole
Which vessels does the efferent arteriole arise from?
Glomerular capillaries
which arteriole does the particular capillaries arise from?
Efferent arteriole
What is the main blood supply to the kidney?
Renal artery
What is the main blood outflow of the kidney?
Renal vein
What are the three main processes of the nephron?
Filtration
Reabsorption
Secretion
Which artery distributes blood towards the glomerulus?
Afferent arteriole
Where does ultrafiltration occur within the kidney?
Bowmans capsule
What does the Bowmanโs capsule produce?
Filtrate
Which network of capillaries are enclosed within the bowman capsule?
Glomerulus
Where is the filtrate reabsorbed within the kidney?
Proximal convoluted tubule
Loop of Henle
Distal convoluted tubule
Which network of capillaries if formed by the efferent arterioles?
Vasa recta, capillary network follows the loop of Henle
How is blood filtered within the Bowmanโs capsule?
Fenestrations between endothelial cells of the glomerular capillaries.
Podocytes with pedicels cover the glomerular capillaries basement membrane resides between the glomerular endothelium and podocytes, the pedicles interdigitate to form filtration slits, ensuring that platelets and plasma proteins do not filter through the tubule.
Filtration membrane forms
What cells cover the glomerular capillaries and assist with filtration?
Podocytes
What role is performed by podocytes?
Podocytes with pedicels cover the glomerular capillaries. Basement membrane resides between the glomerular endothelium and podocytes. The pedicels interdigitate to form filtration slits, ensuring that platelets and plasma proteins do not filter through the tubule. Maximises absorption of filtrate.
What is a filtration membrane?
Prevents passage of blood cels, large plasma proteins, and negatively charged particles. Negatively charged particles have difficulty filtering the capsular space because the proteins associated with the filtration membrane repel negative charged substances
What is the role of mesangial cells?
Contract to help regulate the rate of filtration of the glomerulus
How Is a high pressure maintained with the renal corpuscle?
A sufficient hydrostatic pressure is required to force the fluid through the fenestrations between endothelial cells of the glomerular capillaries. Relatively large diameter of the afferent arteriole in comparison to the efferent arteriole generates sufficient pressure gradient to enable constituents of plasma to pass through with the exception of erythrocytes and plasma proteins.
What is the filtration barrier?
Filtration barrier (size & charge dependent): Highly permeable to fluids & small solutes; impermeable to cells and plasma proteins.
What is the diameter to which water, ions and small proteins can pass through?
70nm diameter
Which type of pressure within the glomerular capillaries forces fluid outwards into the Bowmanโs capsule?
Hydrostatic pressure
Which type of pressure is exerted by plasma proteins?
Oncotic pressure
What is oncotic pressure?
Osmolarity generated produces a tendency for water to be drawn inwards along water potential gradient, across semipermeable membrane
What type of pressure is exerted by the interstitial fluid with Bowmanโs capsule?
Exerts a hydrostatic pressure
What is the net ultrafiltration pressure?
HPgc = Hydrostatic pressure in glomerular capillaries
HPbw = Hydrostatic pressure in bowmanโs capsule
ฯgc = Oncotic pressure of plasma proteins in glomerular capillaries
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