B4W1 Renal Flashcards
What is the concentration of components in plasma from highest to lowest?
Na, Cl, HCO3, K, Ca, PO4
What is the major osmolyte of the extracellular fluid?
Na+
Compare the ionic composition between interstitial fluid and plasma.
Essentially the same but there is no fluid protein in the interstitial fluid
Compare Na+, Cl-. and K+ concntrations between extra and intracellular fluid.
Extracellular
- High Na+ and Cl-
- Low K+
Intracellular
- Low Na+ and Cl-
- High K+
Effect of increasing extracellular NaCl?
Swelling of the ECF compartment
Depletion of ICF compartment
Effect of adding pure water?
Increase ICF compartment
Depletion of the ECF compartment
Effect of isotonic NaCl Water?
Increase ECF compartment
No change in ICF compartment
What is the major determinant of ECF volume?
Total body Na+
What is the primary function of the kidneys?
Filtration
Reabsorption
Secretion
What percentage of cardiac output is received from the kidney?
20%
How can you identify superficial glomeruli?
They are the only glomeruli that have a bifurcated interlobular arteries.
What is a claudin?
A claudin is a family of proteins that determine the selectivity of tight junctions
Two claudins on two cells near one another form a selectivity barrier
Leaky Junction Characteristics
Electrical Resistance, Chemical Gradient, Transepithelial Voltage are low
Transport Rate is high
What is Glomerular filtration rate?
Rate of fluid movement from capillary space into Bowman’s Space
Volume filtered per unit of time
Average Kidney Glomerular Filtration Rate
180 L/Day
Average Daily Urine Amount
1-2 L/Day
Endogenous Molecule Used to Measure GFR
Creatinine
What is the functional unit of the kidney?
The nephron
Two main Components of a Nephron
Glomerulus and Tubule
Glomerulus Function
Filter Blood
Nephron Tubule Function
Convert Filtrate into Urine
What are the two main types of nephrons?
Cortical and Juxtamedullary
85% Cortical
15% Juxtamedullary
Main components of Glomerulus or Renal Corpuscle
Vasculature, Mesangial Cells, and Bowman’s Space. All of which are incased by epithelial cells to form Bowman’s Capsule
Endothelial Cell Characteristics of the Proximal Tubule
Extensive Apical membrane with a lot of in-folding, has many mitochondria, and a large nucleus
What is the Loop of Henle
Medullary Structure that contains S3 Segment of the Proximal Tubule, thin descending limbs, thin ascending limbs, and thick ascending limbs.
Segments of the Proximal Tubule
S1 S2 and S3
S1 Renal Cortex
- Greatest Rate of Transport
S2 Medullary
S3 Outer Medullary
- Has lowest rate of transport
- Has the highest gradient
Thin Descending Limbs
5% of filtered water reabsorbed but no Na+
Thin cells, few mitochondria, no membrane in-folding
Thin Ascending Limbs
Na+ Maybe reabsorbed or secreted depending on the gradient
Thin Cells, few mitochondria, and no membrane in-folding
Thick Ascending Limbs
Reabsorb
-20-30% NaCl
-K+
-Ca2+ and Mg2+
-HCO3-
Increase NaCl reabsorption in response to vasopressin
Secrete Tamm-Horsfall Protein
Does not reabsorb water
A lot of mitochondria, little apical membrane in-folding, but a lot of basolateral in-folding
Role of Tamm Horsfall Protein (Uromodulin)
Role in immunity and stone prevention
Macula Densa
Senses NaCl for tubuloglomerular feedback
Regulate Renin Release
Release paracrine factor
Large nuclei, a lot of mitochondria, basolateral portion is in contact with mesangial cells, the afferent arterioles, and efferent arterioles
What characteristics make a goof GFR Marker?
Freely filterable, not reabsorbed or secreted, breakdown or accumulated by kidney, and physiologically inert
Downsides of Creatinine as a biomarker
Increases in muscle mass increase creatinine
Influences on the glomerular filtration barrier
Blood Pressure/Flow, Urine obstruction, change in extracellular volume, and reaction to hormones
