Genitourinary 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 5 main functions of the kidney?
1) Excretion: Excretion of metabolic products; urea; uric acid and creatine
2) Excretion of foreign substances e.g drugs
3) Homeostasis of body fluids,electrolytes and acid-base balance
4) Regulation of blood pressure
5) Secretion of hormones e.g renin and erythropoietin
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 peritubular 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 Bowman’s 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
How is blood filtered within the Bowman’s capsule?
Filtered firstly by the glomerular basement membrane which allows water,ions and small proteins to pass.The epithelial podocytes in the Bowman’s space are the 2nd filter.
What cells cover the glomerular capillaries and assist with filtration?
Podocytes
What role is performed by podocytes?
Allow water and small solutes to pass through slits between podocytes
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 Bowman’s 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 Bowman’s capsule?
Exerts a hydrostatic pressure
What is the net ultrafiltration pressure?
HPgc = Hydrostatic pressure in glomerular capillaries
HPbw = Hydrostatic pressure in bowman’s capsule
πgc = Oncotic pressure of plasma proteins in glomerular capillaries
𝑷𝒖𝒇=𝑯𝑷𝒈𝒄 −H𝑷𝒃𝒘−𝝅𝒈𝒄
What is GFR?
Glomerular filtration rate: The volume of fluid filtered from the glomeruli into the Bowman’s capsule per unit time (ml/minute)
Sum of filtration rate of all functioning nephrons
What is the equation for glomerular filtration rate
𝑮𝑭𝑹=𝑷𝒖𝒇 𝒙 𝑲𝒇
What is the ultrafiltration coefficient?
Product of membrane permeability and surface area available for filtration; changes in Kf will result in GFR imbalances, reduction in GFR characteristic feature of renal disease, accumulation of excretory products within the plasma
What is the GFR range for males?
90-140ml/min
What is the GFR range for females?
80-125ml/min