1 Renal Intro Flashcards
What are the major functions (4) of the kidney?
- Regulation of balance: water and ions
- Regulation of osmolality and volume
- Excretion of metabolic waste and foreign chemicals
- Secretion of hormones (Renin and Erythropoietin)
When urine flow = 1100 ml.day
Steady state (excreting just enough water)
When urine flow > 1100 ml/day
Negative water balance (excreting too much water)
When urine flow < 1100 ml/day
Positive water balance (not excreting enough water)
Name 3 examples of NEGATIVE sodium and water balance (excreting too much)
- Diarrhea
- Diuretic medication
- Insufficient aldosterone
Name 3 examples of POSITIVE sodium and water balance (excreting too little)
- Excess steroids
- CHF
- Salt-retaining renal disease
Is the cortex granular or striated?
granular
Is the medulla granular or striated?
striated
Gross anatomy of ureter: Urine is discharged into _______ from _______ ___________.
pelvis; renal pyramids
The pressure in the ureter is usually ________.
very low
Basic unit of kidney?
nephron
3 components of Nephron?
- Tubular component 2. Vascular component 3. Combined component (JGA)
Draw out the nephron including; 1. Renal corpuscle (with glomerulus and bowman’s capsule) 2. Proximal tubule 3. LOH (descending thin and ascending thick) 4. Distal convoluted tubule 5. Collecting duct
draw it..
What drains the Bowman’s capsule?
the proximal tubule
What is the main function of the LOH?
Generate osmotic gradient in medulla that allows kidney to concentrate urine
What happens in the proximal tubule?
60-80% of filtered solute and water are reabsorbed (isosmotic)
Where is the JGA in relation to the glomerulus?
where thick ascending limb of LOH passes between afferent and efferent arteriole
What happens in the distal convoluted tubule?
Some reabsorption of water and ions (iso-hyposmotic)
What hormone controls water permeability in the collecting duct of the nephron?
Vasopressin (ADH)
Where is the final concentration of urine adjusted?
the collecting duct
What’s the difference between a cortical nephron and a juxtaglomerular nephron?
Cortical nephrons: - have glomeruli in the outer cortex - LOH is short and doesn’t extend into medulla Juxtaglomerular nephrons: - glomeruli near corticomedullary border - LOH long and extends deep into medulla
Ability to produce concentrated urine is proportional to ______________.
the number of juxtaglomerular nephrons
All nephrons function in ___________. (orientation)
in parallel (collecting ducts shared by many nephrons
What are the three layers of the filtration barrier? Draw it…
- Capillary endothelium 2. Basement membrane (basal lamina) 3. Capsular epithelial cells (podocytes, slits between them where urine flows)
Name the 3 parts of the JGA
- Macula densa 2. Extraglomerular mesangial cells 3. Granular cells
What’s the function of the JGA?
- Helps control GFR - Controls renin secretion (BP and volume)
In response to what molecule do mesangial cells contract?
Angiotensin II
Where are mesangial cells found?
Between and within the capillary loops
How many capillary beds are there? What are they called?
2; Glomerular and peritubular
Vasa recta is found in what layer and it follows what structure?
medulla; LOH
Cortical arteries give off _________ arterioles.
afferent
There are 2 arterioles (________ and ________) and 2 capillary beds (__________ and __________) . They are IN _______.
(afferent and efferent) (glomerular and peritubular) IN SERIES
Important function of vasa recta?
- supply nutrients to medullary tissue - recovery of water
Draw out distribution of blood flow…. (slide 19)
draw it…
What type of receptors are renal nerves?
Sympathetic A1 receptors (release NE and DA)
A1 receptors are on both the ________ and the ________, but primarily on the __________ arterioles.
afferent, efferent, afferent
The renal nerves have no ______________ innervation
parasympathetic
Stimulation by the SNS tends to ________ RBF and GFR, but the simultaneous release of PGE2 and PGI2 __________ the effect
reduce; opposes (reductions in RBF and GFR are minimized)
Granular cells (JGA) are innervated by _______.
SNS
Renin released upon stimulation of _________.
Beta receptors
Purpose of glomerular filtration is production of a _____________ filtrate.
protein-free
Name the steps of renal function
- Glomerular filtration 2. Tubular reabsorption (from lumen to PTC) 3. Tubular secretion (from PTC to tubular lumen) 4. Excretion (substance appears in urine)
How fast is the average GFR?
120-125 ml/min
