KIDNEYS KIDNEYS KIDNEYS KIDNEYS KIDNEYS KIDNEYS KIDNEYS KIDNEYS

KIDNEYS KIDNEYS KIDNEYS KIDNEYS KIDNEYS KIDNEYS KIDNEYS KIDNEYS

What is urine? Mostly water Solutes: urea (from breakdown of protein), uric

acid (from breakdown of nucleic acids), creatinine (from breakdown of creatine phosphate in muscle fibers), sodium, potassium, ammonia,

NOT FOUND: glucose, proteins, rbc, hemoglobin, wbc, and bile

ANATOMICAL PARTS REGIONS:

Renal cortex: superficial

Renal medulla: inner region containing• renal pyramids:

Apex (papilla) face the hilus (kidney indentation)

• renal column: between pyramids

More parts

minor calyx; major calyces – collect urine from pyramid

Renal pelvis – collect urine from calyces

Nephrons – filter urine from blood; microscopic

URETER

URINE FORMATION

Occurs in nephrons: mostly in renal cortex

Leaves through collecting ducts

1. Glomerular filtration Water and small

solutes from blood Glomerular

capsule Due to high bp

2. Tubular reabsorption

Returns useful nutrients to blood Ex: water, glucose, sodium, calcium

3. Tubular secretion

Brings some substances into the urine that are not already there.Ex: ammonium ions, hydrogen, some

drugs

blood supply

1. What is the difference between the renal cortex and the renal medulla?

2. What part of the kidney is the hilus?

3. What part of the kidney collects urine from a medullary pyramid?

4. What is the function of a nephron?

5. Which structure of the urinary system leaves the kidneys with urine?