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 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

 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.) Glomerular Filtration Rate (GFR)

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. Oncotic pressure

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 -, Ca 2+, PO 4, HCO % of H 2 0. 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 HCO 3 -. Collecting duct - reabsorbs the remaining 2% of Na+ only if the hormone aldosterone is present. H 2 0 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.

Rennin Erythropoietin: Vitamin D3: Hormones Produced by the Kidney

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

URETER Mengalirkan urin  vesika urinaria P: cm 3 lapisan * Luar : jaringan ikat * Tengah : longitudinal & sirkuler * Dalam : selaput lendir

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