Kidney Structure and Function Flashcards
what can oral health impact on in the rest of the body?
CVS disease, rheumatoid arthritis, respiratory diseases, metabolic disease, kidney disease
what do the kidneys do?
process blood and rid the body of the waste products of metabolism via urine
what is the main function of the kidneys?
maintain internal homeostasis of fluid
what type of organs are the kidneys?
excretory organs
what is the function of the kidneys in the urinary system?
produce urine
what is the function of the ureters in the urinary system?
convey urine
what is the function of the bladder in the urinary system?
store urine
what is the function of the urethra in the urinary system?
void urine
where do the kidneys lie in relation to the peritoneal cavity?
retroperitoneal
what are the 3 distinct parts of the kidney?
cortex, medulla, pelvis
what does the cortex contain?
85% of all kidney tubules (nephrons)
what happens in the medulla?
urine is concentrated which prevents excessive water loss
what is the pelvis of the kidney?
collection area for urine which is funnelled into the ureter
comment on the vascularity of the kidney
highly vascular
what is the function of the renal artery in the kidney?
it delivers blood from abdominal aorta
how much blood does the kidney process per minute?
1.2 litres
starting from the renal artery what are the blood vessels of the kidney?
renal artery - segmental arteries - lobar arteries - interlobar arteries - arcuate arteries - interlobular arteries - afferent arterioles - glomerular capillaries - efferent arterioles - peritubular capillaries (vasa recta) - interlobular veins
what is the nephron?
the basic functional unit
what does the nephron do?
filter blood plasma and excrete waste products of metabolism in urine
what are the 2 types of nephron?
cortical nephrons and juxtamedullary nephrons
what is the structure of the nephron starting from the glomerulus?
glomerulus - Bowmans capsule - proximal convoluted tubule - loop of Henle - distal convoluted tubule - collecting duct
what parts of the nephron form the renal corpuscle?
glomerulus and Bowmens capsule
what is the function of the renal corpuscle?
filtration
what parts of the nephron form the renaul tubule
proximal convoluted tubule, loop of Henle, distal convoluted tubule, collecting duct
what is the function of the renal tubule?
reabsorption and secretion
what is the structure of the glomerulus?
a network of fine capillaries, a single layer of endothelial cells resting on a basement membrane, it is fenestrated (has perforations)
what does the fenestrations in the glomerulus do?
enables rapid filtration of blood plasma
what is the glomerulus surrounded by?
Bowmans capsule
what is the bowman capsule?
a cuplike structure surrounding the glomerulus
what are the layers of the bowmans capsule?
parietal layer and visceral layer
what is the visceral layer of the bowmans capsule comprised of?
specialised epithelium - podocytes
what is the filtration barrier formed of?
glomerular endothelium, basement membrane and pedicels of podocytes
what shares the same basement membrane as the pedicels?
fenestrated endothelium
comment on the permeability of the filtration barrier
freely permeable to water and small molecules but not large proteins or cells
what do the size and charge of the filtration slits of the filtration barrier allow?
provide the barrier with the ability to determine which molecules are filtered
what is the first step in blood processing?
glomerular filtration
what are the steps of glomerular filtration?
1 - unfiltered blood arrives at the glomerulus via the afferent arteriole , 2 - blood components filtered through the filtration barrier , 3 - filtered blood exits the glomerulus via the efferent arteriole
what is filtration facilitated by?
pressure gradient
what is filtered in the glomerulus?
water, glucose, amino acids, urea, creatinine, sodium chloride, calcium phosphate, potassium bicarbonate
what is not filtered in the glomerulus ?
cells, large proteins (haemoglobin), negatively charged proteins (albumin)
what is the glomerular filtration rate?
the rate at which blood is filtered through the bowmans capsule
what is the GFR primarily driven by?
glomerular hydrostatic pressure
what is the GFR counteracted by?
hydrostatic pressure in the bowmans capsule and glomerular osmotic pressure
what factors influence the GFR?
hydrostatic pressure, osmotic pressure, systemic blood pressure, renin-angiotensin system, disease
what is the normal GFR?
125ml/min OR 180l/day
what does kidney damage do?
reduce GFR
what does reduced GFR mean?
inefficient blood clearance and waste removal so waste products accumulate in blood
what is used to estimate GFR?
serum creatinine and urea measurements
what is stage 1 chronic kidney disease?
kidney damage with normal kidney function. GFR = 90 or higher
what is stage 2 chronic kidney disease?
kidney damage with mild loss of kidney function, GFR = 89-60
what is stage 3a chronic kidney disease?
mild to moderate loss of kidney function, GFR = 59-45
what is stage 3b chronic kidney disease?
moderate to severe loss of kidney function, GFR = 44-30
what is stage 4 chronic kidney disease?
severe loss of kidney function, GFR = 29-15
what is stage 5 chronic kidney disease?
kidney failure, GFR = less than 15
what does your GFR number tell you?
how much kidney function you have
what percentage of fluid is reabsorbed in the renal corpuscle?
99%
