Chapter 19-20 (kidney physiology) Flashcards
Describe the glomerular filtration. What are the results?
It basically cleans the blood by getting rid of all the waste and stuff and turns the waste and stuff into urine (filtrate) (only 1%).
180L of blood is filtered in 24 hours and only 1% of filtrate turns into urine
What makes the filtration process in the glomerulus so efficient?
The diameter of the arteriole in the glomerular is bigger so that is what makes it more efficient
What determines the hydrostatic pressure in the glomerulus? How is this different from normal capillaries in the body?
The large input of the afferent arterioles and the small output of the efferent arterioles.
Name all the pressures in the renal corpuscle (5)
- Glomerular Hydrostatic pressure
- Capsular hydrostatic pressure
- net hydrostatic pressure
- Blood colloid osmotic pressure
- net filtration pressure
What do each of the pressures in the renal corpuscle do?
- Glomerular Hydrostatic pressure
- Capsular hydrostatic pressure
- net hydrostatic pressure
- Blood colloid osmotic pressure
- net filtration pressure
- Glomerular Hydrostatic pressure- the primary force that drives the filtration of fluid from the blood within the glomerulus into the Bowman’s capsule (pushes out)
- Capsular hydrostatic pressure- it is back pressure on the glomerular hydrostatic pressure and provides resistance on it and opposes it (pushes in)
- net hydrostatic pressure- pushes fluid from the glomerular capillaries into Bowman’s capsule
- Blood colloid osmotic pressure- Draws fluid into the capillary beds
- net filtration pressure- Determines the rate of at which fluid is filtered from the blood into the Bowman’s capsule
Which pressures oppose on each other in the renal corpuscle?
The Capsular hydrostatic pressure, and Blood colloid osmotic pressure GO AGAINST THE Glomerular hydrostatic pressure
Which pressures work together in the renal corpuscle?
The Capsular hydrostatic pressure, and Blood colloid osmotic pressure
What is NHP (net hydrostatic pressure)/NFP(Net filtration pressure)?
NHP (Net Hydrostatic Pressure)- is the glomerular hydrostatic pressure (GHP) MINUS the Capsular hydrostatic pressure (CsHP), GHP - CsHP (35mmHg)
NFP (Net Filtration Pressure)- It is the Blood Colloid Osmotic pressure (BCOP) MINUS Net Hydrostatic pressure (NHP). BCOP - NHP (10-15mmHg)
What is the GFR?
It is the amount of filtrate produced in one minute
How do you measure the GFR?
You use the creatinine clearance test and Inulin test
Describe the creatinine clearance test
It measures the amount of creatine that is removed from the blood per minute since glomerular filtration gets rid of the creatine in the kidneys
name the steps of the RAAS
- a decrease in NA+ makes your blood volume drop and blood pressure
- They juxtaglomerular apparatus sense this drop of blood volume and blood pressure
- Granular cells secrete renin
- The liver converts renin into angiotensin I
- ACE enzyme converts angiotensin I into angiotensin II
- Angiotensin II stimulates (turns on) the adrenal cortex to make aldosterone and does vasoconstriction
- Aldosterone promotes reabsorption of NA+ and secretion of K+ from ducts
- Increase blood volume and raises blood pressure
What stimulates the RAAS system? And what are the results?
Decrease in blood volume/ pressure
Results: Water and Na+ is reabsorbed causing the blood pressure and blood volume to increase
Describe how water reabsorption works in the nephron loop (the countercurrent multiplication)
The thin descending limb in the nephron loop is where you start to lose the most fluid/water as you are going down the loop since it is permeable to water (lets it leave) and impermeable to solutes (keeps it in) since the ascending loop is releasing a lot of solutes so water follows BUT you gain water/fluid as you go up the thick ascending limb in the nephron loop since it is impermeable to water/fluid (doesn’t let water out) and soluble to solutes (lets them out) which lets the solutes leave but keeps the water in and doesn’t follow the solutes leaving. POSITIVE FEEDBACK SYSTEM
How do the kidneys manage blood pH?
By reabsorbing bicarbonate into the body and secreting H+ ions by peeing