Chapter 33: Disorders of Renal Function Flashcards
Hilus
medial border of the kidney where the renal artery enter and renal vein and ureters exit
Nephron
functional unit of kidney that cannot be regenerated
Two types: cortical (85%) and juxtamedullary (15%)
Juxtamedullary Nephrons
largely concerned with urine concentration
area where renin is released
Glomerulus
high-pressure capillary filtration system
encased in thin, double-walled capsule called Bowman’s Capsule
Afferent arterioles
carry blood containing nitrogenous wastes to glomerulus
Efferent arterioles
carry filtered pure blood from glomerulus back to the circulatory system
The PSNS causes bladder ____
emptying
contracts the detrusor muscle and relaxes the internal sphincter
The SNS promotes bladder _____
filling
relaxes the detrusor muscle and contracts the internal sphincter
The parasympathetic lower motor neruons for the detrusor muscle and external sphincter are located ______
in the sacral segments S2 - S4
Pelvic Nerve
part of the PSNS
acetylcholine bins to M3 receptor = contraction of detrusor muscle (sensation of needing to urinate)
Pudendal Nerve
somatic
acetylcholine binds to nicotinic receptors = causes external sphincters to contract (hold urine)
Hypogastric Nerve
SNS
norepinephrine binds to alpha and beta receptors
alpha 1 = contraction of the internal sphincter (not under our control)
beta 3 = relaxation of the detrusor muscle
Detrusor-Sphincter Dyssynergia
interruption of pontine control that results in inhibited spinal reflex-controlled contraction of bladder without relaxing the external sphincter
Glomerular Filtration Rate (GFR)
how much filtrate is formed every minute
measure of overall function of the kidney
serum creatinine levels reflect the GFR
Renal Threshold
plasma level at which a substance appears in the urine
Proximal Tubule
responsible for apprx 65% of all reabsorption and secretory processes
almost complete reabsorption of nutritionally important substances
Loop of Henle
absorbs more Na+ and Cl- than water
25% of filtered Na, Cl, and K is reabsorbed and allows for excretion of free water
loop diuretics work here
Distal and Collecting Tubules
relatively impermeable to water
determines final Na concentration of urine
have intercalated cells and principle cells
Intercalated Cells
reabsorbs K+ ions
secretes H+ ions and reabsorbs bicarb
Principle Cells
where aldosterone exerts its action
reabsorbs Na and facilitates movement of K+ into the urine
Antidiuretic Hormone (ADH)
assists in maintenance of the ECF volume by controlled the permeability of the medullary collecting tubules
released for posterior pituitary in response to increased osmolality
Aquaporin-2 channels
move into the cell membrane when ADH binds to vasopressin
results in increased water permeability
Renal Function is innervated by ____
sympathetic nervous system (SNS)
increased SNS activity will cause vasoconstriction = decrease in renal blood flow
______ causes vasoconstriction
Angiotensin II
ADH
Endothelin-1
_____ causes vasodilation
dopamine
nitric oxide
prostaglandins
Juxtaglomerular Complex
feedback control system that determines how much renin should be released to keep the BP within normal range (to maintain a constant GFR)
Aldosterone
reabsorbs Na (water follows) and excretes K+
Atrial Natriuretic Peptide (ANP)
secreted by atrial muscle cells
inhibits kidneys from reabsorbing Na and inhibits the renal secretion of renin (disrupts the RAAS)
works with BNP to decrease preload
______ can compete with uric acid excretion
Salicylates
high uric acid seen in gout or renal calculi
BUN
measures the kidney excretion of urea (end product of protein metabolism)
BUN = 10 - 20
BUN is elevated in ______
kidney failure, high-protein diets, excessive muscle breakdown, and reduced GFR (dehydration)
Serum Creatinine
measures skeletal muscle metabolism
poor test for elderly who have less muscle mass
Drugs need to be _____, ______, and ______ to be excreted.
unbound, ionized, and water-soluble
Erythropoietin
kidney is the main site that releases erythropoietin to produce more RBCs in response to tissue hypoxia
Active form of _____ increases intestinal calcium absorption.
vitamin D (active 1,25 dihydroxycholecalciferol = calcitriol)
Parathyroid Hormone (PTH)
increases calcium in the blood and excretes phosphate
kidney is the site of PTH action
RAAS
Renin – Angiotensin 1 – [ACE] = Angiotensin II and stimulates aldosterone = increase blood pressure
Hydronephrosis
urine-filled dilation of the renal pelvis and calices d/t obstruction of outflow of urine
Calcium Renal Calculus
caused by calcium supplements, calcium-containing antacids, foods high in oxalate, immobilization, hyperparathyroidism
Magnesium-ammonium Phosphate Renal Calculi
staghorn stones
certain bacteria use urease to convert uric acid to ammonia (making urine more alkaline)
alkaline environment = crystalline Mg
tx the UTI and make urine more acidic
Uric Acid Stones
seen with high purine diet, dehydration, and obesity
forms an acidic environment
tx w/ Probenecid, hydration, and make urine more alkaline
Renal Colic
pain that accompanies stretching of duct or ureter
acute, intermittent (with peristaltic movement) and severe flank pain
Noncolicky Pain
caused by stones that distend renal calyx or pelvis
dull, deep ache in flank or back exaggerated by movement and drinking large amounts of water
Glomerulonephritis
inflammation of the capillary loops of the glomeruli
can be acute, rapidly progressive, or IgA neuropathy
Acute Post-Infectious Glomerulonephritis
antigen-anitbody complexes are formed and trapped in the glomerulus following a strep infection causing dec in GFR and increased porosity
Signs/Symptoms of Acute Glomerulonephritis
hematuria proteinuria salt and water retention azotemia headache
Rapidly Progressing Glomerulonephritis
build antibodies against the glomerular basement membrane and obstruct Bowman’s space
usually associated with autoimmune disorders like lupus (SLE) or Goodpasture’s
S/Sx of Rapidly Progressing Glomerulonephritis
flu-like symptoms
oliguria
abdominal or flank pain
IgA Neuropathy Glomerulonephritis
Buerger disease
deposits of IgA immune complexes deposit in the in glomerulus causing inflammation
common cause in Asians 20 - 30
gross hematuria is major sign
Nephrotic Syndrome
protein wasting thta occurs with glomerular damage rsulting in large amounts of protein loss difficult to replace with diet
S/Sx of Nephrotic Syndrome
edema (due to loss of colloidal oncotic pressure)
decreased BP
lipiduria, hyperlipidemia, hypoalbuminemia, loss of globulins (antibodies)
Hypoalbuminemia puts patients at risk for _____
drug toxicity
drugs bind to albumin
Pyelonephritis
inflammation of the kideny pelvis and parenchyma from a bacterial infection (most commonly E. coli)
S/Sx of Pyelonephritis
absurpt onset of fever/chills
CVA tenderness
can have lower UTI symptoms
untreated can lead to sepsis and renal failure
