-
Organs involved
- Kidneys
- Ureter
- Urinary Bladder
- Urethra
-
Kidney locations
- At level of T12 - L3 vertebrae (12th rib)
- Right Kidney slightly lower than Left (due to liver)
-
Kidney blood flow pathway (start @ aorta)
aorta -> Renal Artery -> Segmental artery -> Interlobar Artery -> Arcuate artery -> Cortical radiate artery -> Afferent arteriole -> GLOMERULUS (capillaries) -> Efferent arteriole -> Peritubular capillaries -> Cortical Radiate vein -> Arcuate vein -> Interlobar vein -> Renal Vein (no segmental vein) -> Inferior Vena Cava
-
Nephron structure & role
- composed of GLOMERULUS & Renal Tubule
- Responsible for FORMING urine
-
Glomerulus
- specialized for filtration
- sits within Glomerular (Bowman's) capsule (1st part of renal tubule)
- Afferent arteriole: comes from cortical radiate artery - FEEDS glomerulus
- Efferent arteriole: receives blood that has passed through glomerulus & goes into the peritubular capillaries & then cortical radiate vein
-
Glomerular Filtration
- Passive process
- H20 & solutes (SMALLER than proteins) go through capillary walls
- PROTEINs & blood cells usually too large to pass through
- Filtrate collected in glomerular capsule & leaves via renal tubule
-
Tubular Reabsorption
- Some is passive, MOST is active process
- Most reabsorption occurs in PROXIMAL convoluted tubule
- peritubular capillaries reabsorb: H20, glucose, aa's, Ions
- Waste products (not reabsorbed): urea(protein breakdown), uric acid(nuc acid breakdown), creatinine(creatine metabolism in muscles)
-
Tubular Secretion
- Important to get rid of substances NOT already in filtrate
- Some material move from Peritubular capillaries into RENAL Tubules: H+ & K+ ions, Creatinine
- These materials move towards the ureter
-
Urine vs. filtrate
- Filtrate: contains everything blood plasma does (except proteins)
- Urine: what remains AFTER filtrate has Lost most of its H20, nutrients & necessary ions
- Urine contains NITROGENOUS wastes and other non-essential substances
-
Solutes found in urine
- Na+ & K+ ions
- Urea, uric acid, creatinine
- ammonia
- Bicarbonate ions
-
Solutes should NOT be found in urine
- Glucose
- WBCS (pus)
- RBCs
- blood proteins
- hemoglobin
- bile
-
Ureters
- Slender tubes attaching to kidneys and bladder
- CONTINUOUS with the renal pelvis
-
Urinary bladder
- Smooth muscular sac
- 3 Openings: 2 FROM ureters, 1 TO urethra
-
Urethra
- controls urine release
- Internal sphincter: involuntary (smooth muscle)
- External sphincter: voluntary (skeletal muscle)
-
Urethra gender differences
- Males: through the prostate & penis (also passageway for sperm), 20cm(8inch)
- Females: Only carries urine, along vagina wall, 1inch
|
|
