Renal Flashcards
Blood vessel into glomerulus
Afferent Arteriole
Which of thevnephron is actively involved in the process of filtration?
Glomerulus and Bowmans Capsule
Three layers of kidney
Renal cortex- contains corpuscules and convoluted tubules
Renal medulla- loops of Henley and collecting tubules and renal pyramids
Renal pelvis-
Blood flow to kidney
Abdominal aorta
Renal artery
Afferent arteriole
Blood flow from kidney
Efferent arterole
Renal vein
Inferior vena cava
Bowmans capsule
Contains glomerulus
Arterioles enter bowman
Cluster of blood vessels in bowmans capsule
Glomerulus
Proximal convoluted tubule
Reabsorption of water, ions, nutrients
Loop of Henle
Further reabsorption water (descending limb) and both sodium and chloride ions (ascending limb)
Distal convoluted tubule
Secretion of ions, acids, drugs, toxins.
Variable reabsorption of water sodium and calcium (hormone controlled)
Diuretics/antidiuretics work here
Collecting System
Collecting Duct -variable reabsorption of water and reabsorption/secretion of sodium, hydrogen and bicarb ions
Papillary duct- delivery of urine to minor calyx
ureter
Hydrostatic Pressure
pressure exerted by any fluid in a space
Consists of 3:
Glomerular hydrostatic pressure (55mm hg)
Blood osmotic pressure (30mmhg)
Capsular hydrostatic pressure (15mmhg)
overall net outward pressure = 10mmhg
Hydrostatic Pressure is affected by:
Systemic Blood pressure
AKI Definition
Acute kidney injury is an abrupt decline in glomerular filtration
failure of kidneys to excrete waste products of metabolism
inability to maintained electrolyte and acid base homeostasis
AKI Characteristics
Reduction in GFR High urea/ creatine Reduce urine output electrolyte imbalance drowsiness Labile BP
Pre-renal
Decreased blood supply to kidneys
ie: Dehydration, renal artery thrombosis, low bp, medications
Intra-renal
Abnormalities within kidney
Ie: Infection, rabdomyolysis, medications NSAIDS for example, cancer, tumorlysis, vasculitis, acute tubular necrosis, contrast, ischeamia, toxins.
Post renal
Resulting from obstruction below renal pelvis
Kidney stones, prostate, cancer, fibroids
Acute Vs Chronic
Acute- sudden, rapid, reversible
Chronic- progressive, non reversible, nephron less
Management of AKI
- Haemodynamic monitoring and support
- control sugars
- fluid management isotonic crystalloids
- nutritional support
- diuretics (fluid overload)
- Low use contrast
- Initiate RRT in life threatening electrolyte/fluid changes
RASS System
Drop In BP Macula densa cells (stimulated) Constriction of afferent arteriole reduction in filtration rate (GFR) renin released by the JGA renin to liver = AG1 AG1 to lungs changed to AG2 with ACE AG1 causes vasoconstriction This increases vascular resistance and maintains hydrostatic pressure
Part of nephron which chiefly regulated reabsorption of potassium
Distal convoluted tubule
Kidneys produce the following substances
Renin- JGA
Calcitrol- cells in proximal convoluted tubule
Erythropoetin- kidneys- bone marrow to produce red blood cells
Aldosterone
AG2 causes release of aldosterone
increases sodium retention and water reabsorption
Anti-diuretic hormone
-Secreted by posterior pituitary
-Increases water permeability in the tubule increased reabsorption of water= reduced urine output
A lack of ADH leads to excessive urine output (diabetes insipidus)
-Negative feedback
Antidiuretic hormone- negative feedback loop
Osmoreceptors in hypothalamus detect rise in plasma osmolarity
ADH secreted by posterior pituitary gland
Binds to collecting duct
Causing water channels to open therefore water is reabsorbed into blood.
Stimulation of osmoreceptors decreases
Atrial Natriuretic Peptide (ANP)
Opposite of ADH
Atrial wall cell receptors- stretch
Releases ANP
Down regulated renin and AG2 and Aldosterone
Causes increased GFR
Diureses
Reduction in blood volume and blood pressure
ANP also causes vasodilation and reduction in BP
Hyperkalaemia treatment
IV Calcium chloride or gluconate- protects cardiac muscle Insulin-Glucose infusion Salbutamol Sodium Ziconium Consider Dialysis
Renal replacement therapy- processes
Filtration Convection Adsorption Diffusion Osmosis
Indications for RRT
Acidosis Electrolyte disturbance Toxins/Drugs Fluid overload Uraemia Temperature Control
Filtration
Ultrafiltration
Movement of fluid through semi-permeable membrane caused by a pressure gradient
High to low
Positive, negative and osmotic pressure from non-permeable solutes
Ie in Glomerulus
Convection
Water pushed across dialysis filter and carries solute from blood stream
known as solvent drag
Hydrostatic pressure involved
Pressure gradient
Adsorption
Filter attracts solute, molecules and attach to filter
Rapid onset
size of molecules affects
Diffusion
Movement of solutes from high to low concentration
Passive process
OSMOSIS
Movement of water across semipermeable membrane
from and area of high to low concentration to produce equilibrium
passive
based on solute concentration
CVVHD
Diffusion and ultrafiltration to remove waste products
Dialysate rate determines rate of clearance
Anticoagulation
Citrate:
Decreases ionised calcium- prevents clotting
Prolongs circuit life
Heparin
Fluid Management
Insensible losses: 800ml
Therapeutic window to treat AKI-conceptual framework
