Renal system and Nephron components

Kidneys

• Structure: Cortex, Medulla, renal pelvis

• Function is Filtration, electrolyte balance, hormone production

• Blood flow is Renal Artery > segmental Interlobar > Arcuate > Cortical Rádiate > Afferent Arterioles > Glomerius (Filtration Site) > Efferent Arterioles > Peritubular capillaries (Cortex) > Vasa Recta (Medulla) > Cortical Radiate Veins > Arcuate Veins > Interlobar Veins > Renal Veins > Inferior Vena Cava

Nephron

• Structure: Glomerulus, Bowman’s capsule, Proximal Convoluted Tubule, Loop of Henle, Distal Convoluted Tubule, Collecting Duct

• Function is Filtration, Reabsorption, secretion and urine formation as well as Regulates fluid balance, waste excretion, and BP

• Afferent Arteriole > Glomerulus > Efferent Arteriole > Peritubular Capillaries/Vasa Recta

Ureters

• Structure: Muscular Tubes (~25-30cm) with 3 layers (Mucosa, Muscularis, Adventitia)

• Function is transports urine from the kidneys to the bladder via peristalsis and gravity

• Blood is supplied by branches of Renal Arteries, Gonadal Arteries, Common iliac arteries

Urinary Bladder

• Structure: Hollow Muscular organ with layers (Mucosa, Detrusor Muscle, Adventita/ Outer Layer)

• Function is to store urine and contracts to expel urine during Micturition

• Blood flows in the superior and inferior Vesical Venous Plexus

Urethra

• Structure: Thin Walled Muscular tube, Length differs by sex (Males is longer)

• Function is to conduct Urine from the bladder to the outside and in males serves as passage for semen

• Blood is supplied by branches of internal pudendal artery

Renal Corpuscle

• Role is Filtration

• Glomerulus- A network of Capillaries that receives blood from the Afferent arteriole and acts like a filtration unit allowing molecules to pass through the Bowman Capsule

Renal Tubule

• Function is reabsorption and secretion

• Proximal Convoluted Tubule is where most of the reabsorption occurs as products are reabsorbed into the bloodstream

• Loop of Henle has 2 parts, Ascending Limb Impermeable to water but allows salt and descending is opposite

• Distal Convoluted Tubule- regulates ion balance by reabsorbing sodium and calcium while secreting potassium and hydrogen ions

Collecting duct

• Function is excretion by transporting urine to the renal pelvis then moving it to the ureter

• As well as collects filtrate from multiple nephrons and concentrates urine by allowing water reabsorption