Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Nephrology PPT 6 Nephrology Basics Lecture Notes
Nephrology ? Basics
Renal Physiology
? Glomerular Filteration
? Tubular Function
? Endocrine Functions
? Renal blood flow normally drains pproximately
20% of the cardiac output, or 1000 mL/min.
? Blood reaches each nephron through the
afferent arteriole leading into a glomerular
capillary where large amounts of fluid and
solutes are filtered to form the tubular fluid.
? The distal ends of the glomerular capil aries coalesce to
form an efferent arteriole leading to the first segment
of a second capil ary network (cortical peritubular
capil aries or medul ary vasa recta) surrounding
the tubules.
? Thus, nephrons have two capil ary beds arranged in a
series separated by the efferent arteriole that
regulates the hydrostatic pressure in both capil ary
beds.
? The distal capil aries empty into smal venous branches
that coalesce into larger veins to eventual y form the
renal vein.
? The proximal tubule is responsible for
reabsorbing ~60% of filtered NaCl and water,
as well as ~90% of filtered bicarbonate and
most critical nutrients such as glucose and
amino acids.
? The proximal tubule uses both cellular and
paracellular
transport
mechanisms.
? The loop of Henle consists of three major
segments: descending thin limb, ascending thin
limb, and ascending thick limb.
? These divisions are based on cel ular morphology
and anatomic location, but also correlate with
specialization of function.
? Approximately 15?25% of filtered NaCl is
reabsorbed in the loop of Henle, mainly by the
thick ascending limb.
? The loop of Henle has an important role in
urinary concentration by contributing to the
generation of a hypertonic medullary interstitium
in a process cal ed countercurrent multiplication.
? The loop of Henle is the site of action for the
most potent class of
diuretic agents (loop diuretics) and also
contributes to reabsorption of calcium and
magnesium ions
? The distal convoluted tubule reabsorbs ~5% of
the filtered NaCl.
? This segment is composed of a tight
epithelium with little water permeability.
? The collecting duct modulates the final
composition of urine.
? The two major divisions, the cortical collecting
duct and inner medullary collecting duct,
contribute to reabsorbing ~4-5% of filtered
Na+ and are important for hormonal
regulation of salt and water balance.
Arteries/brain/adrenals
Kidneys/adipose tissues
Renal Function Tests
? Blood Urea
? Serum Creatinine
? Serum Electrolytes
? Serum Calcium
? Serum Phosphate
Urine Examination
? Dip stick
? Microscopy
? 24 hrs Urine
Renal Imaging
? Skiagram
? USG
? CT scan
? MRI
This post was last modified on 07 April 2022