URinary brookdale

urinary system is a vital organ system responsible for 

 filtering blood, producing, storing, and excreting urine, and maintaining the body's homeostasis

urinary system plays a crucial role in 

 regulating blood volume, blood pressure, electrolyte balance, and acid-base balance. 

1. primary organs responsible for filtering blood and forming urine.

2. Tubes that transport urine from the kidneys to the bladde

3. A muscular sac that stores urine.

4. A tube that expels urine from the bladder out of the body.

5. These provide neural control and blood supply to the

   urinary organs.

1. Kidneys:

2. Ureters:

3. Bladder

4. Urethra:

5. Associated nerves and blood vessels

kidney is broadly divided into two main regions:

Cortex: The outer region of the kidney where blood filtration occurs to form urine.

Medulla: The inner region responsible for collecting and excreting urine.

These are 8 to 18 conical subdivisions located within the renal medulla. They

contain numerous tubules and secreting portions of the nephrons, playing a key role in urine

concentration.

Pyramids:

These are extensions of the renal cortex that project into the medulla

between the renal pyramids. They contain blood vessels and fibrous material, providing

structural support and anchoring the cortex.

Renal Columns

The apex of each medullary pyramid, where urine empties into the minor

calyces and then into the major calyces.

Renal Papilla:

 A large cavity located within the renal sinus where urine collects from the major

calyces before being transported to the ureters.

Renal Pelvis

These are long, tube-like structures that exit the kidney at the hilum and transport

urine from the renal pelvis to the urinary bladder.

Ureters: 

A hollow, muscular organ designed for urine storage. It can hold approximately

700-800 ml of

urine.

Bladder:

 The bladder empties through this tube-like structure via a process called

micturition or urination, which involves both voluntary and involuntary muscle contractions.

Urethra:

 urinary system performs several critical functions to maintain the body's internal environment

Ridding the body of liquid, nitrogenous waste products.

Maintaining overall water balance within the body.

Maintaining electrolyte balance by regulating ion concentrations.

Maintaining acid/base balance by adjusting pH levels in the blood.

Specific Functions

More specifically, the urinary system:

• Regulates blood volume, pressure, and pH.

• Regulates the concentration (osmolarity) of electrolytes such as

• Reabsorbs essential substances like glucose, ensuring they are not lost in urine.

• Excretes metabolic waste products including urea, creatinine, and uric acid.

• Releases important hormones such as renin (involved in blood pressure regulation) and

• erythropoietin (EPO) (stimulates red blood cell production).

Renal Artery and Renal Vein enter and exit the kidney respectively at the;serving as the main conduits for blood supply and drainage.

hilum

is the functional unit of the kidney, responsible for filtering blood and forming

urine

nephron

 nephron consists of two main parts:

Renal Corpuscle: Where blood plasma is filtered.

Renal Tubule: Where filtered fluid passes through for reabsorption and secretion.

The renal corpuscle is composed of

Glomerular capillaries

Bowman's capsule

A network of tiny blood vessels where filtration occurs.

Glomerular capillaries

: A double-walled cup that surrounds the glomerular

capillaries.

Bowman's capsule 

 Made of podocytes that intricately wrap around the single layer of

endothelial cells of the glomerular capillaries, forming the inner wall of the capsule. These

cells create filtration slits.

Visceral layer:

 Forms the outer wall of the capsule, providing structural support.

Parietal layer

is a long, convoluted tube that extends from Bowman's capsule:

Renal tubule

he first segment where most reabsorption of water

and solutes occurs

Proximal Convoluted Tubule (PCT)

A U-shaped segment that extends into the medulla, crucial for establishing

the osmotic gradient.

Loop of Henle

Permeable to water.

Descending limb

 Impermeable to water, but actively reabsorbs ions.

Ascending limb:

 Involved in fine-tuning reabsorption and secretion, under

hormonal control

Distal Convoluted Tubule (DCT

 Receives fluid from multiple nephrons and plays a final role in water

reabsorption and urine concentration.

Collecting Duct:

The nephrons perform three essential processes to form urine

GFR

Tubular reabsorption, and tubular secretion.

the amount of filtrate formed in all the renal corpuscles

of both kidneys each minute.

GFR 

is the formation of an ultrafiltrate (protein-free fluid) across the

glomerular membrane. Not all blood is filtered; some leaves via the efferent arteriole and

returns to the renal venous system.

Glomerular filtrate 

The process by which useful substances from the filtrate are returned

to the blood.

Tubular Reabsorption:

The process by which waste products and excess ions are moved from

the blood into the filtrate for excretion.

Tubular Secretion:

The fluid that passes from the blood into Bowman's capsule, containing water, ions,

glucose, amino acids, and waste products, but lacking large proteins and blood cells.

Filtrate

The process where substances needed by the body (e.g., water, glucose,

essential ions) are moved from the renal tubule back into the blood capillaries.

Reabsorption

The process where waste products, excess ions, and certain drugs are actively

transported from the blood into the renal tubule to be excreted in urine.

Secretion:

The final fluid product formed by the kidneys, containing waste products and excess

water, ready for excretion.

Urine:

visceral and parietal layers of the renal corpuscle, specifically the_______ their

fenestrations, along with the basal lamina, form a highly selective dialysis membrane. This

membrane prevents the passage of large molecules like proteins and blood cells while allowing

water and small solutes to pass through.

 podocytes 

Fluid is filtered from the 

It enters 

the filtered fluid then enters the

 traveling sequentially through the:

glomerular capillaries.\

Bowman's Space (the space between the two layers of the glomerular capsule).

renal tubule, Proximal Convoluted Tubule (PCT) Loop of Henle Distal Convoluted Tubule (DCT)

From the DCT, the fluid flows into the

collecting ducts, then to the minor calyces, major calyces, and finally to the renal pelvis before reaching the ureters.

 two main types of nephrons, distinguished by the length of their loops of Henle:

Cortical nephrons

Juxtamedullary nephrons

 These have short loops of Henle that primarily reside in the renal cortex.

They are involved in routine urine formation.

These possess long loops of Henle that extend deep into the

renal medulla. They are critical for creating a concentration gradient in the renal medulla,

which enables the kidney to excrete very dilute or very concentrated urine, depending on the

body's hydration needs

Cortical nephrons

Juxtamedullary nephrons