Int 2: Renal System Flashcards
Kidney structure: Match the components to the area
a) loops of Henle
b) all glomeruli
c) convoluted tubules
d) cortical collecting duct
e) medulla collecting ducts
- Medulla
- Cortex
a) Medulla
b) Cortex
c) Cortex
d) Cortex
e) Medulla
What % of cardiac output goes to the kidneys
20%
Why do the kidneys need such high blood flow?
- High blood flow supports high glomerular filtration rate (180L per day, 5L Blood every 40 minutes)
Which is which, Hydrostatic pressure and colloid oncotic pressure // pushing pressure and pulling pressure.
There is a measure for each of these in the glomerular capillaries and Bowman’s capsule
Hydrostatic = pushing pressure
Colloid oncotic = pulling pressure
(Net push is greater than net pull)
In capillaries, pushing pressure a)_______ as fluid is removed but this is counteracted by b)_______________. Meanwhile, pulling pressure progressively c)___________
- Efferent arteriole constriction
- rises
- falls
a) falls
b) efferent arteriole constriction
c) rises
Which of the following cause GFR (glomerular filtration rate) to increase/decrease?
a) Nitric oxide
b) noradrenaline
c) Prostaglandins
d) ANGII
e) ET-1
a) increase
b) decrease
c) increase
d) decrease
e) decrease
The filtration barrier consists of 3 layers, what are they? good luck mate as if your remembering this
- capillary endothelium (-ive charge)
- basement membrane (-ive charge)
- podocytes (epithelium)) slit diaphragm
The nephron is:
- transporting tubule
- epithelial cell monolayer (polarised and specialised proteins for transport)
- a basement membrane
- filtration pressure gives unidirectional flow along the tubule
- axial fluid fluxes across the epithelial monolayer modify urine
What are the 4 main sections of the nephron?
- Proximal tubule
- Loop of Henle
- Distal convoluted tubule
- Collecting ducts
What is the structure and function of the glomerular endothelium?
- the inner most layer of cells that line the glomerular capillaries.
- composed of many fenestrated / porous structure that permits the passage of ions , water and small solutes from the blood into the glomerular filtrate.
- prevent filtration of large molecules
What is the structure and function of the basement membrane?
- lies between GE and podocytes
- is a specialised extracellular matrix composed of collagen, laminin and other proteins
- further restricts passage or larger molecules + aids structural integrity
What is the structure and function of podocytes?
- wrap around glomerular capillaries to provide structural support for them
- also help regulate filtration
What is the structure and function of Slit Diaphragms?
- narrow spaces or gaps located between foot processes of podocytes
- further regulate the filtration process
How do the following factors play a role in the composition of the glomerular filtrate:
a) molecular charge
b) molecular size
a) The filtration barrier is negatively charged due to the presence of glycoproteins and proteoglycans in the basement membrane. This repels molecules with a negative charge such as proteins.
b)The barrier is also selectively permeable to smaller molecules such as amino acids and water.
How much of the following do the kidneys filter and excrete per day and what hormones are involved:
a) water
b) Na+
c) K+
a) 180L/day. ~1.5L/day, Vasopressin
b) 25000mmol/day, 150mmol/day, RAAS
c) 800mmol/day, 25-1600mmol/day, Aldosterone
Hard Q: List 3 features of the Proximal tube of the kidney
- Leaky epithelia
- High water permeability of cells
- Very high paracellular water permeability
