The Urinary System Overview

Kidneys filter blood, removing toxins, wastes, and excess ions, regulating blood volume and composition, and maintaining water and electrolyte balance.

A temporary storage reservoir for urine.

Tubular structures that transport urine from the kidneys to the bladder.

Structure that carries urine from the bladder to the outside of the body.

The kidneys are located in the retroperitoneal space, in the superior lumbar region, and extend from T12 to L3 vertebrae, with the right kidney slightly lower than the left.

Fibrous capsule preventing kidney infection.

Fatty cushion surrounding the kidney, holding it in place.

Outer fibrous connective tissue layer holding the kidney in its place.

The vertical cleft on the medial surface of the kidney, leading to the renal sinus.

The light colored, granular superficial part of the kidney.

The region of the kidney containing cone-shaped medullary pyramids.

Inward extensions of cortical tissue that separate the pyramids in the kidney.

A medullary pyramid and its surrounding capsule.

A flat, funnel-shaped tube in the kidney, lateral to the hilus in the renal sinus.

Large branches of the renal pelvis that collect urine from the papillae and empty it into pelvis.

The structural and functional unit of the kidney that forms urine.

A tuft of capillaries associated with a renal tubule in the nephron.

The blind, cup-shaped end of a renal tubule that completely surrounds the glomerulus.

The glomerulus and its Bowman's capsule together.

Fenestrated epithelium that allows solute-rich, protein-free filtrate to pass into the glomerular capsule.

Modified, branching epithelial cells forming the visceral layer of Bowman's capsule.

Openings in the foot processes of the glomerulus allowing filtrate to pass into the capsular space.

Part of the renal tubule with cuboidal cells, microvilli, and mitochondria, responsible for reabsorption and secretion.

Hairpin-shaped loop of the renal tubule, with thin and thick segments.

Part of the renal tubule with cuboidal cells, no microvilli, and primarily involved in secretion.

Nephrons located mainly in the kidney cortex.

Nephrons located near the cortex-medulla border, with long loops of Henle, involved in concentrated urine production.

Network of capillaries in the nephron, involved in blood filtration.

Capillaries surrounding the renal tubules, involved in reabsorption and secretion.

Arteriole supplying blood to the glomerulus.

Arteriole draining blood from the glomerulus.

The muscular tube that drains urine from the bladder and expels it from the body.

Muscles that control the flow of urine, keeping it inside the bladder until you need to urinate.

Involuntary muscle at the bladder-urethra junction that keeps urine in the bladder.

Voluntary muscle around the urethra that controls urination.

The female urethra is near the vaginal opening, in front of it.

The male urethra has three parts: prostatic, membranous, and spongy (penile).

Low-pressure, porous capillaries that arise from efferent arterioles and absorb substances.

Long, straight capillaries of juxtamedullary nephrons.

The initial step in urine formation, involving filtration of blood in the glomerulus.

Process of reclaiming valuable substances from the filtrate in the tubules.

Transport of substances, such as unwanted molecules, from the blood to the filtrate in the tubules.

Slender tubes that transport urine from kidneys to the bladder.

Transitional epithelium (inner lining), smooth muscle layer, and fibrous connective tissue (outer layer).

Muscular sac that stores urine temporarily.

Triangular region of the bladder where the ureters and urethra enter.

Transitional epithelium, thick muscular layer, and fibrous adventitia.

Filtration of blood, removing toxins, metabolic wastes, and excess ions, maintaining blood volume and composition, and balancing water and salts.

A temporary storage organ for urine before expulsion from the body.

Slender tubes transporting urine from kidneys to bladder.

Tube transporting urine from the bladder to outside the body.

Retroperitoneal space in superior lumbar region, extending from T12 to L3 vertebrae; right kidney slightly lower than left.

Fibrous capsule surrounding kidney, protecting from infection.

Fatty cushion surrounding the kidney, supporting and cushioning it.

Outer fibrous tissue layer, anchoring kidneys to the body.

Vertical cleft on medial side of kidney, leading to the renal sinus.

Light colored, granular outer kidney layer.

Inner kidney region containing cone-shaped pyramids.

Inward extensions of cortical tissue that separate the medullary pyramids in the kidney.

A medullary pyramid and its surrounding capsule.

A flat, funnel-shaped tube located in the renal sinus, lateral to the hilus, that collects urine.

Large branches of the renal pelvis that collect urine from the papillae and empty into the renal pelvis.

The structural and functional unit of the kidney that forms urine.

A tuft of capillaries associated with a renal tubule in the nephron.

The cup-shaped structure that surrounds the glomerulus, collecting the filtrate.

The glomerulus and its Bowman's capsule.

Fenestrated endothelium in the glomerulus that allows solute-rich, protein-free filtrate to pass into Bowman's capsule.

Openings between foot processes that allow filtrate to pass into the capsular space.

Part of the renal tubule with cuboidal cells, microvilli, and mitochondria; reabsorbs water and solutes, secretes substances.

Hairpin-shaped loop of renal tubule with thin and thick segments.

Part of renal tubule with cuboidal cells, no microvilli, primarily involved in secretion.

Nephrons located mainly in the cortex.

Nephrons near the cortex-medulla border, with long loops of Henle; involved in concentrated urine production.

Network of capillaries in the nephron involved in blood filtration.

Capillaries surrounding renal tubules, involved in reabsorption and secretion.

Arteriole supplying blood to the glomerulus.

Arteriole draining blood from the glomerulus.

Low-pressure, porous capillaries that absorb substances, arising from efferent arterioles and emptying into the renal venous system.

The muscular tube that carries urine from the bladder outside the body.

Long, straight capillaries of juxtamedullary nephrons, playing a role in urine concentration.

The initial step in urine formation, filtering blood in the glomerulus, creating a filtrate.

Muscles that control urine flow, keeping it in the bladder until you urinate.

Involuntary muscle at the bladder-urethra junction.

Reclaiming valuable substances from the filtrate in the renal tubules, such as water and nutrients.

Voluntary muscle surrounding the urethra.

Transport of substances into the urine, such as waste products not filtered initially.

Slender tubes transporting urine from kidneys to the bladder.

The female urethra is situated near the vaginal opening, in front of it.

Epithelial lining (transitional), smooth muscle layer, and fibrous connective tissue (outermost).

The male urethra has three parts: prostatic, membranous, and spongy (penile).

Muscular sac storing urine temporarily.

Triangular region of the bladder where ureters and urethra meet.

Transitional epithelium, a thick layer of smooth muscle, and fibrous adventitia.

Filtration of blood, removing waste, regulating blood composition, and balancing water.