Renal Basics Flashcards
Components of the renal system
-2 kidneys
-2 ureters
-bladder
-urethra
male and female is the same other then the differences in the length of the urethra
Functions of the Kidneys
- Regulate body fluid volume and composition
- Eliminate metabolic wastes
- Synthesis, release or activate hormones
- Regulates Blood Pressure and Blood Volume
- Regulates Blood pH by excreting and reabsorbing H and HCO3 ions
What hormones are synthesized, released or activated in the kidneys?
- Erythropietin- a glycoprotein hormones that controls erythropiesis (RBC production)
- Renin
- Vitamin D
What mechanisms do we have in our bodies that are going to help us regulate H2O in our bodies
- osmoreceptors in the hypothalamus
- the posterior piturary can release ADH which conserves H2O
- The adrenal cortex can release glucocorticoids and mineralcorticoids such as aldostrone which will help retain Na and excrete K.
What happens when there is a decreased renal perfusion?
- Renin is released by the kidneys
- Angiotensin I is converted to angiotensin II (vasoconstrictor and increases BP) with the help of ACE (comes from the lungs)
- Aldostrone is released and Na retention, pulling water to stay inside also.
Hypothalamus and posterior regulation of blood volume
- low blood volume triggers osmoreceptors to send signal of low blood volume and ADH is released and you get thirsty and your kidneys reabsorb H2O at the distal and collecting tubules
- when too much volume, the osmorecpetors tell the posterior piturary to stop release of ADH and water is secreted
Nephrone
- Functional unit of the kidney that filters the blood
- Reabsorb what we need and secretes ions (glucose, Na, AA) in the urine when we don’t need them
Components of the nephrone
- glomerulus
- proximal tubule
- loop of henle
- distal tubule
- collecting duct
Which products should and which shouldn’t be passing the filtration of the kidneys?
- water, small molecules, ions can easily pass
- blood, proteins, are big and cannot easily pass
Glomerular Filtration Rate (GRF)
Amount of filtrate produced every minute
-generally 99% of the filtrate is reabsorbed and 1% goes into the urine
What supplies the kidneys with blood
-the renal artery
- How much blood passes through the kidney’s every minute?
- In an healthy person how much of the cardiac output goes to the kidneys
- 1,000 ml
- 20-25%
Describe the renal circulation of blood
- renal artery
- afferent arterioles
- glomerular capillaries
- efferent arterioles
- peritubular capillaries
- vasa recta
- How much urine does an adult produce per day?
- What factors influence the amount of urine produced in a day
- 1- 2 Liters
- environmental factors, level of hydration, activity levels, weight, health of the individual
Classifications for polyuria, oliguria, anuria
- polyuria- more then 2.5 L in an day
- Oliguria- less then 400 ml in a day
- anuria- less then 100 ml in a day