Kidney Structure and Function Flashcards
what are the main diseases that have close associations with oral health
- cardiovascular disease
- rheumatoid arthritis
- respiratory diseases
- metabolic disease
- kidney disease
what is the main understanding of why the oral health can impact the general health of a person
inflammation from an infection in the mouth can contribute to the overall inflammatory burden in the body, and this is where the problems arise.
what are the kidneys
excretory organs that process blood and rid the body of the waste products of metabolism via urine
how do kidneys maintain blood pressure
by controlling the fluid and electrolyte homeostasis
what is the centre of all kidney functions
fluid homeostasis
what are the main functions of the kidney
- control blood pressure
- regulate acid base composition
- vitamin D metabolism to convert it into an active form the body can use
describe the gross anatomy of the urinary system
- two kidneys produce urine
- ureters convey the urine
- bladder stores the urine
- urethra voids urine
what is the hilum of the kidney
this is the indentation on their medial side where all the connected structure are found
describe the kidneys location
posterior abdomen, retroperitoneal
encased by the renal fat pad
label this
what are the three distinct parts of the kidney
- cortex
- medulla
- pelvis
describe the cortex of the kidney
this is where 85% of all kidney tubules are found
outer part
describe the medulla of the kidney
this is the site where urine is concentrated, and it prevents excessive water loss
found underneath the cortex
describe the pelvis of the kidney
this is the collection area for urine which is funnelled into the ureter
what encases the kidneys
dense irregular fibrous capsule
describe the vasculature of the kidney
a highly vascular organ, renal artery delivers blood directly from the abdominal aorta
how many litres of blood are filtered per minute in the kidneys
1.2 litres
how much of cardiac output goes to the kidneys for filtration
one fifth
describe the vascular hierarchy of the kidneys
renal artery
segmental arteries
lobar arteries
interlobar arteries
arcuate arteries
interlobular arteries
describe the vascular anatomy at the level of arterioles and capillaries in the kidneys
interlobular arteries
afferent arterioles
glomerular capillaries
efferent arterioles
peritubular capillaries
interlobular veins
what occurs at the peritubular capillaries
this is the site of oxygena nd nutrient delivery to the kidney
what are the two capillary beds of the kidneys
peritubular capillaries for blood delivery
glomerular capillaries for blood filtration
where is filtration in the kidneys
at the glomerular capillaries
what surrounds the glomerulus
bowmans capsule
what is the basic functional unit of the kidney
the nephron
what are nephrons
structures optimally evolved to filter blood plasma and excrete waste products of metabolism in urine
what are the two kinds of nephrons in the kidneys
cortical nephrons
juxtamedullary nephrons
describe cortical nephrons
located in the cortex, with a short loop of henle that only just extends into the medulla
most of the nephron is in the cortex
describe juxtamedullary nephrons
these are next to the medulla, and the loops of henle are very long which is important for concentrating urine and conserving water in the body
describe the features of nephrons
glomerulus
bowmans capsule
proximal convoluted tubule
loop of henle
distal convoluted tubule
collecting duct
what is involved in the renal corpuslce
glomerulus and bowman’s capsule
involved in filtration and removal
describe the renal tubule
this is the proximal through to the distal tubule, involved in reabsorption and secretion
what happens in renal tubules
this is where fine tuning occurs so the body can get rid of what it doesnt want in the blood
what is the glomerulus
a capillary bed that branches from the afferent arteriole and comes back together to form the efferent arteriole
a network of very fine, fenestrated capillaries that enables the rapid filtration of blood plasma
why do glomerular capillaries need to be fenestrated
to make them leaky and allow for filtration of molecules and fluid from the blood into the nephron
describe bowman’s capsule
a cuplike structure surrounding the glomerulus
what are the layers to bowman’s capsule
parietal, outer layer made of simple squamous
visceral, inner layer, comprised of podocytes
what are podocytes
epithelial cells with foot like processes that wrap around the capillaries
what forms the filtration barrier
glomerular endothelium
basement membrane
pedicels
what are pedicels
processes from the podocytes
what do pedicels wrap around
the glomerular capillaries
what do pedicels share the basement membrane with
fenestrated endothelium
describe the permeability of the filtration barrier
freely permeable to water and small molecules but not large proteins or cells
what provides the barrier that determines which molecules are filtered
size and charge of filtration slits
what is the first step in blood processing
glomerular filtration
describe the stages to glomerular filtration
1 - unfiltered blood arrives at the glomerulus via the afferent arteriole
2 - blood components are filtered through the filtration barrier
3 - filtered blood exits the glomerulus via the efferent arteriole
what facilitates the glomerular filtration
hydrostatic pressure
why does blood arrive faster than it can leave
the afferent arterioles have a larger diameter than the efferent arterioles
what can be freely filtered in the glomerulus
- water
- glucose
- amino acids
- urea
- creatinine
- sodium
- chloride
- calcium
- phosphate
- potassium
- bicarbonate
what is creatinine
a waste product of muscle metabolism that is freely filtered across the barrier
what is not filtered out of the blood at the glomerulus
cells
large proteins like haemoglobin
negatively charged proteins like albumin
what is the glomerular filtration rate
the rate at which blood is filtered through the glomerulus into the bowman’s capsule
what are the main pressures involved in glomerular filtration rate
glomeruluar hydrostatic pressure
hydrostatic pressure in the bowman’s capsule
glomerular osmotic pressure
what counteracts the glomerular hydrostatic pressure
as fluid is pushed from capillaries into bowman’s space, it fills with fluid and this counteracts it
what can influence the glomerular filtration rate
hydrostatic pressure
osmotic pressure
systemic blood pressure
renin angiotensin system
disease
what is the normal, healthy glomerular filtration rate
125 ml a minute
what is kidney function equal to
the glomerular filtration rate
what does a reduced glomerular filtration rate cause
inefficient blood clearance and waste removal
what measurements are used to estimate the glomerular filtration rate
serume creatinine and urea in the urine
what happens to the glomerular filtration rate as the stages of kidney disease progess
it decreases
how long does it take for kidney issues to manifest into systems
stage three when there has been a loss of more than half of kidney function
how many litres of blood are filtered a day
180
