What are the 6 functions of the urinary system?
- 1. electrolyte balance
- 2. Excete water nitrogenuous urea, creatine, etc)
- 3. Regulates water level/balance, which turns regulates BP
- 4. pH balance (long term control)
- 5. Creates erythropopitin for RBC production
- 6. Kidneys important for activating Vit. D, and renin for BP control
T or F: Renal arteries deliver more blood to the kidneys than they actually need
up to 20-25% of cardiac output (1-1.25 L/min)
Which tube carries urine out of the kidneys into the urinary blader?
What is Ptosis?
People who have a lack of adiose tissue and do not have enough support to keep the kidneys from drooping
What are renal calculi?
T or F: as osm goes deeper into the medulla, it starts to increase: .12osm -> .3 osm
What is the blood vessel called that feeds into every nephron? Which part of the nephron does it enter?
Afferent arteriole: it goes into a ball of leaky capillaries called the Glomerulus
What is the first thing that happens to the blood in the glomerulus?
Filtration: lose 10% water volume and small molecules
How much filtrate is produced per day? Where in the glomerulus does this filtrate get caught in and then led to?
- It gets caught in the Bowman's capsule leading to the renal tubules
After filtration in the glomerulus, what happens next in the nephron?
Tubular reabsorption: reclaims water and the molecules we want in our body?
Which molecules are passed and blocked during tubular reabsorption?
- Molecules < 3nm pass: ions, glucose, urea, amino acids
- Molecules >7-9nm blocked: plasma proteins
After tubular reabsorption in the nephrons, what is the third thing to happen?
What is the official word for urination?
What is the net filtration pressure (NFP) formula? What does it mean?
NFP = hydrostatic pressure of blood (55mmHg) - Osmotic Pressure (30mmHg) - Capsular Hydrostatis P (15mmHg) = 10mmHg
- NFP is the pressure that helps to move filtrate from the glomerulus into bowman's capsule, a combination of these pressures.
- Hydrostatic pressure helps the out flow of filtrate into the bowman's capsule, and the other two pressures oppose it
- Even though the net filtration pressure is the subtraction of all the forces, the net force is always positive in favor of glomerulur hydrostatic pressure
What is glomerular filtration rate and its typical value?
It is how much blood passes through the glomerulars every minute: 100-125 ml/min
After going through the glomerulus, what are the four parts of the nephron tubules does blood go through during the filtration process?
- 1. proximal convoluted tubule
- 2. Loop of Henle - ascending and descending
- 3. Distal convoluted tubule
- 4. Collecting Tube
What happens in the proximal convoluted tubule? What is the flow rate and osm at the end of the pct?
- reabsorb 65% of h20 and lots of solute (eg glucose)
- flow rate: 35ml/min; 0.3osm
What is the descending Loop of Henle permeable and not permeable to? What is osm and flow rate?
- Permeable to h20 but not solute
- flow rate: 20ml/min
- osm: 0.3-> 1.2osm
What is the ascending loop of henle permeable and not permeable to?
What is the osm?
- It is not permeable to h20, but actively pumps sodium out
- osm: pumps can maintain 0.2 osm difference between two sides of the membrane
What is the main function of the distal convoluted tubule?
Why is the collecting tube not permeable to h20? When does it have the ability to be permeable to h20?
- the collecting tubule is next to the loop of henle, which has high osm. If it was normally permeable to h20, water would escape from the collecting tube.
- ADH: pituitary releases this to increase permeability of the collecting tube by inserting aquaporins
What does aldosterone do in the collecting duct and where is it released from?
Released from the adrenal cortex, it tells collecting duct to reclaim sodium
T or F: kidneys can function when BP is below 45mmHg
What is the role of the juxtaglomerular apparatus?
Monitors BP of afferent arteriole
What do the afferent arterioles release when bp is low?
What do the macula densa cells in the DCT monitor? How do they effect the GFR?
- osm of filtrate: they have the ability to constrict afferent arteriole or trigger increased BP
- - this is to keep GFR in the target range to keep kidneys functioning
How do diuretics effect the kidneys?
- It slows the release of sodium, keeping the osm high in the tubules.
- - This pushes water into the tubules and increasing amount of urine
Fill in the blank:
We get our water intake from...
___% cellular resiration
What is the tyical value in liters?
- 30% food
- 60% water
- 10% cellular respiration
- 2.5L typical value
What are the ways we lose water in our body? How much do we usually lose a day?
- 28% lungs & skin
- 60% urine and 4% feces
- 8% pespiration
What is the tyical pH range for our body?
- 7.35 - 7.45
- - 7.4 being the ideal value
What are the buffer systems in our blood and cells to regulate pH?
- bicarbonate in blood
- phosphate in cells, as well as proteins
T or F: pulmonary ventilation can effect pH
What can the kidneys do to control pH? is this long or short term
Long term: can excete H+ or HCO3-