kidney A&P Flashcards
what % of blood in circulation can go through the renal artery at once?
20
what are the main functions of the kidney?
filter and excrete waste products - produce urine
- Water and electrolyte balance
- Producing EPO for RBC production
how is urine produced?
- ## Metabolic waste and electrolyte are excreted by the kidneys to form urine
how does urine exit the kidneys?
- Urine is transported from kidneys to bladder by ureters
- Leaves body via urethra (opens in perineum in female and penis in male)
where does the kidneys extend from?
T12 to L3
which kidney is lower and why?
right - due to presence of liver
what type of organ is the kidneys in terms of peritoneum?
lie retroperitoneally
what are kidneys encased in?
layers of fascia and fat
what makes up renal capsule?
tough fibrous capsule
what makes up the internal structure of the kidney?
- Renal parenchyma divided into cortex and medulla
from cortex to medulla, where does urine collect?
- Cortex extends to medulla dividing into triangular shapes – renal pyramids
- Apex of renal pyramid = renal papilla – collects urine from each pyramid
where do afferent arterioles arise from?
- Renal artery: from superior mesenteric artery they divide into interlobular arteries
- Interlobular arteries: pass into cortex and form afferent arterioles
what do afferent arterioles form?
capillary network, glomerulus and then efferent arterioles
what is the outer 2/3 of renal cortex supplied by?
efferent arterioles form peritubular network supplying nephron tubules with oxygen and nutrients
what is inner 1/3 of cortex and medulla supplied by?
vasa recta
how much fluid does the kidneys supply daily?
200L
describe the process of glomerular filtration
passive process - pushing fluid and solute through membrane
what does the membrane of Bowmans capsule contain?
3 layers - fenestrated epithelial, basement membrane and podocytes
what does fenestrated endothelial filter?
allows blood contents except cells through
what does basement membrane prevent passing through?
prevents proteins through due to charge
what do podocytes in glomerulus do?
selective filtration after fenestrated and basement membrane
what is GFR?
glomerular filtration rate
volume of fluid filtered in a minute – depends on net filtration pressure, total available SA and permeability
how is GFR maintained in high blood pressure?
- In high blood pressure: maintains GFR by constricting afferent arteriole
how is GFR maintained in low blood pressure?
- Low pressure: maintains GFR by dilating smooth muscle in afferent arteriole
