Renal system - - introduction to the kidneys

Question 1

Kidney functions (1)

Answer 1

• Regulates the extracellularfluid (ECF)
– ECF volume
• Water & Na+ balance
– Electrolyte composition
• Na+, Cl-, K+, Ca2+, H+, bicarbonate,
phosphate, sulfate, magnesium
– Osmolarity
• 300mOsm

Question 2

Kidney functions (2)

Answer 2

• Acid-basebalance
• Waste disposal
– Eg. Urea & foreign compounds (drugs etc)
• Hormoneproduction
– Erythropoietin, renin (blood volume), vitamin D activation

Question 3

Urine composition

Answer 3

varies as the kidneys maintain homeostasis

Question 4

structure of renal system

Answer 4

kidney = produces urine
Ureter = transports urine toward the urinary bladder
urinary bladder = temporarily stores urine prior to elimination
urethra = conducts urine to exterior; in males, transports emen as well

Question 5

kidneys

Answer 5

retroperitoneal - behind peritoneal cavity

Question 6

Structure of the kidney

Answer 6

• Outer cortex
• Inner medulla
– Renal pyramids
• Urine drains from renal pyramids into renal pelvis
• Urine leaves via the ureter

Question 7

renal vascular supply

Answer 7

aorta > renal artery > segmental a. > arcuate a. > cortical radiate ar. > afferent arteriole > glomerulus (capillaries) > efferent arteriole > pertibularcapillaries and vasa recta > cortical radiate vein >arcuate v. > interlobar v. > renal v. > inferior vena cava

Question 8

The nephron

Answer 8

Functional units of the kidneys (where urine is produced)
• Renal corpuscle
• Renal tubule
• Collecting system

Question 9

Two types of nephrons

Answer 9

• Cortical nephrons
– 80%
– ShortloopofHenle
– Mostly in cortex
• Juxtamedullary nephrons
– 20%
– LongloopofHenle
– Dips deep into medulla
* balancing sodium and water in body

Question 10

Vascular component of the nephron

Answer 10

Afferent arteriole > glomerulus efferent arteriole > peritubular > capillaries/vasa recta

Question 11

How do we make urine?

Answer 11

1. Glomerular filtration - only occurs at renal corpuscle
2. Tubular reabsorption - both occur in renal tubule (2,3)
3. Tubular secretion
   (Excretion)

Question 12

Glomerular filtration

Answer 12

nondiscriminant filtration of a protein-free plasma from the glomerulus into Bownman’s capsule

Question 13

Tubular reabsorption

Answer 13

selective movement of filtrated substances from the tubular lumen into the peritubular capillaries