Kidneys Structure And Function Flashcards
Urinary system
Kidneys, ureter, bladder and urethra
Functions of urinary system
Excretion - removing waste from body fluids
Elimination- discharge of waste products in form of urine
Homeostatic :
RRSA
Regulating blood volume and pressure
Regulating plasma concentrations and ions eg, potassium, sodium , chlorine and calcium
Stabilises blood ph (hold onto or eliminate hydrogen ions and bicarbonate)
Assists liver (remove toxic waste) and breakdown of amino acid in starvation
Kidney structure
2 kidneys posterior , T12-L3 Left kidney higher than right Suprarenal gland at apex 10cm long, 5.5cm wide and 3cm thicken Weighs 150g Red brown Hang suspended by collagen fibres of renal fascia Collagen fibres can regrow if floating kidney Embedded in perinephric fat capsule Strong fibrous outer capsule
Kidney cross section
Made of renal cortex and Renal medulla
CORTEX - Outer section
Has many cortical columns extending down between renal pyramids
Contains glomerulus
Where filtration happens
MEDULLA- inner part of kidney 6-12 renal pyramids Tip of renal pyramids into the renal sinus at the renal papilla Each one separated by cortical columns Contains collecting ducts
Renal pyramid + Renal cortex + adjacent cortical columns = renal lobe
Renal lobe is urine production
Renal papilla into minor calyx
4/5 minor calyx makes major
2/3 major calyx makes renal pelvis
Good blood supply
Kidney blood supply
RSIACAGEPVCAIR
Renal artery Segmental arteries Interlobar arteries Arcuate arteries Cortical radiate arteries or interlobular Afferent arterioles Glomerulus Efferent arterioles Peri tubular capillaries Venules Cortical radiate veins or interlobular veins Arcuate veins Interlobar veins Renal veins
Nephron
Functional unit of kidney
Tubular structure in cortex of each renal lobe
1.25 million nephrons
Has renal tubule and renal corpuscle
Corpuscle has the bowmans capsule or glomerular capsule and glomerulus
Capillary network and about 50 intertwining capillaries
Filtration
Kidney functions
AWETBED
Acid based balance - bicarbonate absorbed from urine into blood and hydrogen from blood to urine to balance ph of blood
Water balance- kidneys retain or excrete more or less concentrated urine due to hydration
Erythropoiesis- kidneys make red blood cells. Secrete erythropoietin hormone to make more RBCs
Toxin removal - filter out toxins from blood and excretes toxins through urine
Blood pressure reg - Renin released when low sodium, low blood volume or high potassium to increase Bp and vol
Electrolyte balance - balances electrolytes and removes unwanted ones
Vitamin D activation - Vitamin d binds to receptors on kidneys, kidneys release enzymes and vitamin D is now activated
Renal disorders
NCACVCN
Nephritis - kidney inflammation Congenital disorders Acute renal failure Chronic renal failure Vascular disorders Cancer Nephrosis- degenerative disease occurs kidneys
Nephritis
Inflammation of kidneys
Eg, interstitial nephritis, pyelonephritis and glomerulonephritis
Interstitial = between kidney tubules, fluids with cells, matrix etc. Kidneys swell
Pyelonephritis = Starts in ureter tube then spreads renal pelvis and medullary tissue - bacterial
Glomerulonephritis- inflammation of glomerulus
Causes depend on the area = interstitial nephritis due to allergic reaction to medications or long term meds use, or low K+ levels in blood.
Usual symptoms = Abdominal/ kidneys and pelvic pain, burning on urination, nocturia, cloudy pus or blood in urine, swollen hands, face and feet, fever, vomiting and high BP
DIAGNOSIS = Inflammatory and infection markers in blood test, urine test to look for WBCs, blood or bacteria, renal ultrasound or CT scan, raised creatinine, raised blood urea nitrogen or renal biopsy.
Treatment - depends
Interstitial = take off meds and replace with harmless ones. Short term dialysis
Pyelonephritis = bacterial infection from ureter to kidneys , use antibiotics
Glomerulonephritis = Unknown cause, linked to previous infections + beginning of tumour sometimes
Nephrosis
Non inflammatory diseases of nephrons of kidneys
Blood plasma proteins leak into urine and tissues so oedema - osmotic pressures wrong and can’t control blood volume
Degenerative disease
Primary (Unknown cause but kidney doesn’t function properly) and secondary means caused by another disorder like diabetes
Nephrotic syndrome - Excreting too much protein into urine as kidney disorder
Symptoms of nephrosis- Severe swelling of eyes, ankles and feet (can’t control blood volume), foamy urine, weight gain as fluid retention, fatigue and loss of appetite
Diagnosis= Urine analysis (looks for proteins) , blood tests and pressure, and checks for too high cholesterol levels
Blood test may show reduced albumin as more protein lost in urine- lots of protein in urine and low proteins in blood
Treatment: medication to reduce BP and cholesterol, meds to thin blood and suppress immune system and diuretics (remove excess fluid)
Primary = manage symptoms Secondary = manage original disorder causing it
Kidney cancer
Often malignant
Primarily over 50s
Males more than females 3:2 ratio
Links to smoking
Renal cell carcinoma- cancer cells grow uncontrollably in lining of proximal convoluted tubule of nephrons
Asymptomatic in early stages and usually just one kidney. But picked up once it has metastasised to liver, lungs, bones or CNS
after 5 years, if it was caught early you are 96% likely to survive and if caught late then 23% likely to survive
Treatment : remove the affected kidney
Treat metastasis
Vascular disorders
Large blood supply to the kidneys
Vascular disorders more than common at that age
Similar to arteriosclerosis - arterioles thicker and harder and reduce blood supply to kidney - ischaemia (lack of oxygen to kidneys)
Long term ischaemia = renal tissue destructed and chronic renal failure
Has a link to diabetes, hypertension and heart failure
Treatment ; hypertensives to reduce BP and prevent artery walls being damaged
Diuretics help urination so off loads kidneys and heart under less pressure - kidney Problems or heart failure can be put on diuretics
Kidneys decline in aging and some meds can impact kidney function too like antibiotics
Congenital disorders
Adult polycystic kidney
Most common genetic disease
Presents at 40 years or above
Gradual development of cysts on kidneys and expand over time- it is on both kidneys and impedes renal function
Diagnosis confirmed by CT scan or MRI
In children , transmitted as recessive gene + shows up at birth - die in first few months as poor kidney function. Transplant or dialysis unlikely to work,
If you are adult , polycystic kidneys don’t show up until about 40 so you may have passed it to kids without knowing
Treatment : Cysts removed in surgery or a kidney removed if worse than the other. Hypertensives / diuretics.
Acute renal failure
Both kidneys involved - immediate and temporary failure of kidneys to function
Sudden onset
Failure reversible
Many causes= eg, lack of blood flow, inflammation, obstruction, necrosis, severe illness like sepsis or crush injuries, drugs or exposure to chemicals or sever nephritis
Diagnosis - rapid changes to blood and urine tests
Treatment = Reverse primary problem and temporary dialysis
Chronic renal failure
Gradual and irreversible destruction of kidney over long period of time (above and beyond aging)
Caused by= chronic kidney disease, hypertension or diabetes and high cholesterol
When advanced, progress of CRF may be slowed but not stopped as scar tissue and loss of function so more degenerative changes
Phases : Phase 1- decreased reserve
Phase 2- renal insufficiency
Phase 3- end stage renal failure
