Kidney anatomy DIANA

ANATOMI-FISIOLOGI SISTEM
KEMIH
DIANA IRAWATI

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
• Regulasi tekanan darah

KIDNEY

NEPHRON
• Unit fungsional ginjal
• Berjumlah 1-1.2 juta
• Proses pembentukan urin:
 Filtrasi

 Sekresi
 Reabsorpsi

Overview of Nephron Function

Glomerulus

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
• Proses filtrasi yang melewati barier glomerulus belum
berupa urin

Glomerular Filtration Rate
(GFR)

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
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
and secretion

Reabsorption
•Active Transport –requires ATP
▫Na+, K+ ATP pumps
•Passive Transport▫Na+ symporters (glucose, a.a., etc)
▫Na+ antiporters (H+)
▫Ion channels
▫Osmosis

What is Reabsorbed Where?
• Proximal tubule - reabsorbs 65 % of filtered
Na+ as well as Cl-, Ca2+, PO4, 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
present. H20 depending on hormone ADH.

Filtrasi Glomerulus

Sekresi
• Proximal tubule – uric acid, bile
salts, metabolites, some drugs, some
creatinine
• Distal tubule – Most active
secretion takes place here including
organic acids, K+, H+, drugs.

Countercurrent exchange
• The
structure
and
transport properties of
the loop of Henle in
the nephron create the
Countercurrent
multiplier effect.

• A substance to be
exchanged
moves
across a permeable
barrier in the direction
from greater to lesser
concentration.

Hormones Produced by the
Kidney

•Rennin
• Erythropoietin:
• Vitamin D3:

Renin, Angiotensin, Aldosterone:
Regulation of Salt/Water Balance

URETER
• Mengalirkan urin  vesika urinaria

P: 25-30 cm
• 3 lapisan
• * Luar : jaringan ikat
• * Tengah : longitudinal & sirkuler
• * Dalam : selaput lendir

Urethra
•Perempuan : P  4 cm
•Laki –laki : P  ± 15-20 cm
•Letak : retroperioneal torakal
12- lumbal 3