Overview of Kidney, Nephron Anatomy and Function Flashcards
Functions of the Urinary System
- REgulation of Body Fluid Volume - conserving or eliminating water
- Regulation of Fluid Osmolality and Composition - Na+, K+, Ca++, Cl-
- Waste Removal (metabolism by products - nitrogenous wastes(urea), acids)
- Endocrine - Renin(cascade for BP) Erythropoieten (RBC production)
- Territory/Sex marker
Components of Urinary System
- Vascular System
- 2 kidneys
- 2 ureters
- 1 bladder
- 1 urethra
Amount of plasma filtered per day
180 L or 45 gallons
Amount of Urine excreted per day
1.5 L
137 gallons per year, 10265 gallons per life
% of blood flow goint to the kidneys
25% of cardiac output
1250mL/min, 5mL/min/gram of kidney
Kidney
paired, bean shaped organ, 4.5 inches long, retroperitoneal sposition(Tt12-L3), ureters depart from the Hilus, functional unit is Nephron
Primary Kidney Function
conservation and filtration of fluid
cannot restore lost volume
Gross Anatomy
Main Kidney Parts
- Capsule
- Cortex
- Medulla
- Pelvis
Kidney
Capsule
provides protection to the Kidney
tough fibrous layer that surrounds the kidney
Kidney
Cortex
where ultrafiltration and erythropoietin production occur, contains cortical arches and renal columns
between the capsule and medulla
Renal Columns
consists of blood vessels and urinary tubes
medullary extension of renal cortex in between renal pyramids
Kidney
Medulla
8-18 renal pyramids, contains Nephrons
innermost part of the kidney
Renal Calyces
pacemaker cells that stimulate peristalsis which propels urine
Nephron
funcitonal unit, 1-3 million per kidney, 3 cm long
Functions of Nephron
- Filtration of Blood Plasma(concentration)
- Reabsorbtion of water, AA’s, sugar, salts(Acidification)
- Secretion of H, K ions
these funcitons allow urine concentration and acidification
Cortical Nephrons
start high in the cortex and have a short loop of henle that does not deeply penetrate the medulla
majority of Nephrons
Juxtaglomerular Nephrons
cells that produce Renin
produces renin in response to B1 receptors, decrease in renal profusion, decrease in NaCl concentration in the macula densa
5 Principle Nephron Parts
- Renal Corpuscle
- Proximal Concoluted Tubule
- Loop of Henla
- Distal Convoluted Tubule
- Collecting Duct
Renal Corpuscle
primary function is filtration
Renal Corpuslce = Glomerulus + Bowman’s Capsule
Glomerulus
fenestrated(leaky) capilary exchange unit, Filtration Funciton
simple squamous, basal lamina, podocytes, mesangial cells