ANATOMI-FISIOLOGI SISTEM
KEMIH
FISIOLOGI GINJAL
•
Regulasi volume darah melalui proses sekresi air
•
Regulasi elektrolit darah
•
Regulasi keseimbangan asam-basa melalui
eksresi ion H+ dan HCO3
•
Produksi dan sekresi hormon
•
Ekskresi produk sisa metabolisme
NEPHRON
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Unit fungsional ginjal
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Berjumlah 1-1.2 juta
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Proses pembentukan urin:
Filtrasi
Sekresi
Filtrasi Plasma
•
Komponen plasma akan melewati 3 lapisan glomerulus
selama proses filtrasi
1.
Kapiler endotelium
2.
Membran basal
3.
Epitel kapsula bowman
•
Kemampuan molekul melewati membran sangat
dipengaruhi oleh ukuran, bentuk dan pengeluaran
Measure of functional capacity of the
kidney
Dependent on difference in pressures
between capillaries and Bowman’s space
Normal = 120 ml/min =7.2 L/h=180
L/day!! (99% of fluid filtered is reabs.)
Oncotic pressure is the component of total
osmotic pressure due to colloid particles.
Water molecules cross the membrane to
equalize the
concentration of colloid particles on each side.
Reabsorption
•
Active Transport –requires ATP
▫
Na+, K+ ATP pumps
•
Passive
Transport-▫
Na+ symporters (glucose, a.a., etc)
▫
Na+ antiporters (H+)
▫
Ion channels
What is Reabsorbed Where?
• Proximal tubule - reabsorbs 65 % of filtered Na+ as well as Cl-, Ca2+, PO
4, HCO3-. 75-90% of
H20. Glucose, carbohydrates, amino acids, and small proteins are also reabsorbed here.
• Loop of Henle - reabsorbs 25% of filtered Na+.
• Distal tubule - reabsorbs 8% of filtered Na+. Reabsorbs HCO3-.
• Collecting duct - reabsorbs the remaining 2% of Na+ only if the hormone aldosterone is
Sekresi
•
Proximal tubule
– uric acid, bile
salts, metabolites, some drugs, some
creatinine
•
Distal tubule
– Most active
secretion takes place here including
Countercurrent exchange
• The structure and transport properties of the loop of Henle in the nephron create the
Countercurrent multiplier effect.
•
Rennin
•
Erythropoietin:
•
Vitamin D3:
URETER
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Mengalirkan urin
vesika urinaria
P: 25-30 cm
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3 lapisan
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* Luar : jaringan ikat
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* Tengah : longitudinal & sirkuler
Urethra
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Perempuan : P
4 cm
•
Laki –laki : P
± 15-20 cm
•
Letak : retroperioneal torakal
