Anatomy and Functions of the Urinary System

Urinary System Functions

Excretes wastes, maintains blood volume and pH.

Nephron

Functional unit of the kidney, filters blood.

Glomerular Filtration

Initial filtration of blood in the nephron.

Tubular Reabsorption

Returns water and solutes to blood.

Tubular Secretion

Removes wastes from blood into urine.

Micturition

Process of urine expulsion from the bladder.

Renin

Hormone regulating blood pressure via kidneys.

Erythropoietin

Stimulates red blood cell production in bone marrow.

Calcitriol

Active form of Vitamin D, regulates calcium.

Kidney Anatomy

Paired organs, reddish, fist-sized, retroperitoneal.

Hilum

Entry point for vessels and ureters in kidneys.

Renal Capsule

Protective barrier surrounding the kidney.

Perirenal Fat Capsule

Fat layer providing cushioning around kidneys.

Renal Fascia

Connective tissue anchoring kidneys in place.

Renal Cortex

Outer region of the kidney containing nephrons.

Renal Medulla

Inner region of the kidney with renal pyramids.

Minor Calyx

Collects urine from renal pyramids.

Major Calyx

Formed from minor calyces, leads to pelvis.

Renal Pelvis

Funnel-shaped structure draining into ureter.

Urethra

Tube transporting urine out of the body.

Detrusor Muscle

Muscle layer of the urinary bladder.

Trigone

Triangular area in bladder, sensitive to stretch.

Ureter

Tube carrying urine from kidneys to bladder.

Afferent Arteriole

Brings blood to the glomerulus for filtration.

Efferent Arteriole

Carries blood away from the glomerulus.

Juxtaglomerular Complex

Regulates blood pressure and filtration rate.

Cortical Nephron

Type of nephron primarily in the cortex.

Juxtamedullary Nephron

Type of nephron extending into the medulla.

Urine Formation

Includes filtration, reabsorption, and secretion processes.