L26 - Kidney - Structure And Blood Filtration Flashcards
What are the structures in the renal system? (4)
- 2 kidneys
- 2 ureters
- bladder
- urethra
What are the functions of the kidney? (4)
- regulation of water, salts, acid-base balance
- removal of metabolic waste, foreign chemicals
- gluconeogenesis
- production of hormones/enzymes
What are examples of hormones/enzymes that the kidney produces? (3)
- erythropoeitin (control RBD production)
- renin (controls BP and Na+ balance)
- activates vitamin D (regulates Ca2+)
What is the anatomy of the kidney (in cross section)? (5)
- capsule (separates the kidney from the rest of the body)
- cortex
- medulla
- renal pelvis
- urether
What is the output like in one kidney? (3)
- contrain 1 mil nephrons
- feed into collecting ducts
- feed into ureter
What areas of the kidney can the nephron be found in? (2)
- cortex
- medulla
What are the sections of the nephron? (6)
- glomerulus
- bowman’s capsule
- PCT
- loop of henle
- DCT
- collecting duct
Where does blood filtration occur in the nephron? (2)
- glomerulus
- bowman’s capsule
What type of relationship is there between blood vessels and the nephron? What does this allow?
Intrinsic relationship
- allows fine tuning of waste products
What are the key steps in the function of the nephron? (3)
- glomerular filtration
- tubular secretion
- tubular reabsorption
What way does blood flow in from the blood vessel into the bowman’s capsule?
Afferent arteriole to the efferent arteriole
What are the blood vessels like at the glomerulus? And why?
Bunched up
- increases surface area
What are the epithelial cells like of the blood vessels in the glomerulus? And why?
They are more porous
- allows small substances to leave
What are podocytes?
Cells with lots of small projections that wrap around the blood vessels
- sieve substances
What do podocytes allow the absorption of? (8)
- water
- salts
- glucose
- a/a
- urea
- uric acid
- creatine
- small drugs
Anything <8nm
What do podocytes not allow the absorption of? (3)
- cells
- proteins
- protein-bound drugs
Anything >8nm
What are the main steps of glomerular filtration? (3)
- podocytes surround blood vessels in glomerulus
- foot-like process create sieve like structure
- allows free passage of small molecules from blood to kidney tubules
What is the glomerular filtration rate (GFR)?
Volume of fluid filtered from glomeruli to bowman’s space per unit time
How is fluid filtered through glomeruli?
By pressure of flow through blood vessels
What is GFR regulated by?
Adjusting blood pressure either side of glomerulus
How do you reduce GFR? (3)
- constrict afferent flow
- dilate efferent flow
- reduces water and salt loss through excretion
How do you increase GFR? (3)
- dilate afferent flow
- constrict efferent flow
- increases water and salt excretion
What are facts about the kidneys in humans? (2)
- avg person contains 40L of water
- total filtered 4.5 times a day
