Class Notes (836,147)
Canada (509,656)
Brock University (12,091)
Biology (1,629)
BIOL 2P93 (93)

Glomerular Filtration

2 Pages
Unlock Document

Jenny Janke

Intro to Renal Physiology & GLomerular Filtration I. Formation of the Ultrafiltrate a. Filtration Barrier—(3) fenestrae of endothelial cells, basement membrane, & slit membranes on podocyte foot processes i. 3 parameters determine whether solute will cross barrier: 1. size: <5200 A filter freely; > 34000 daltons not filtered *radius & MW are important!* 2. charge: (-) charge is retarded from crossing 3. shape: rod-shaped pass more easily than globular ii. concentration ratio—gives measure of how well solute crosses filtration barrier ([plasma solute]/[urine solute]) b. Physical Factors i. SNGFR = K(ΔP -fΔπ) = single nephron GFR 1. ΔP = change in hydraulic pressure between glomerulus (P ) & GC bowman’s capsule (P ) BC a. Normally, P GC = 45mmHg & P BC = 10mmHg 2. K =ffiltration coefficient = (hydraulic permeability of filtration barrier) x (filtration surface area) a. K ffr kidney is > 2x any other capillary network in body 3. Δπ = oncotic pressure difference across membrane = colloid osmotic pressure a. Rises from 20mmHg to 35 mmHg from afferent to efferent ends b/c plasma proteins are becoming more concentrated b. Since π of bowman’s space ~ 0 (no lg – proteins), Δπ = π GC c. Tends to pull H2O back into capillaries ii. Because glomerular capillaries lie between 2 arteries, hydraulic pressure is relatively constant throughout! iii. Very small net driving force, but large K fllows for high fluid flow rate c. Filtration Profiles
More Less

Related notes for BIOL 2P93

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.