Exam #4: Overview of Renal Physiology Flashcards
What are the three main regions of the kidney?
1) Cortex
2) Medulla
3) Papilla
What is the cortex?
Outer region of the kidney, located under the capsule
What is the medulla?
Central region of the kidney; it is divided into an inner & an outer medulla
What is the papilla?
Innermost tip of the inner medulla that empties into the minor & major calyces (extensions of the ureter)
What is the functional unit of the kidney?
Nephron
How many nephrons are contained within each kidney?
~1,000,000
What are the two major constituents of the nephron?
1) Glomerulus
2) Renal tubule
What is the glomerulus?
- A glomerular capillary network the emerges from an afferent arteriole
- These capillaries are surrounded by Bowman’s Capsule, creating Bowman’s Space
Which direction is blood filtered in in the glomerulus?
Across glomerular capillaries into Bowman’s Space
Beginning with Bowman’s Space, what are the parts of the nephron?
1) Proximal convoluted tubule
2) Proximal straight tubule
3) Loop of Henle
4) Distal convoluted tubule
5) Collecting ducts
What are the three parts of the Loop of Henle?
1) Thin descending limb
2) Thin ascending limb
3) Thick ascending limb
What is unique about the structure of the proximal convoluted tubule? How do these structural changes impact its function?
- Extensive development of microvilli, called a “brush border” on the luminal side
- Provides a large surface area of reabsorption
What are the two different types of nephrons?
1) Superficial cortical nephrons=
- Glomeruli in outer cortex
- Short Loops of Henle that descend only into the outer medulla
2) Juxtamedullary nephrons
- Glomeruli near corticomedullary border
- Large glomeruli
- Longer Loops of Henle that descend into the inner medulla & papilla
Which type of nephron functions in the concentration of urine?
Juxtamedullary nephrons
Describe the blood supply to the kidney.
- Renal arteries branch off the abdominal aorta
- Branches into
1) Interlobar arteries
2) Arcuate arteries
3) Cortical radial arteries - Afferent arterioles
*The afferent arterioles deliver blood to the glomerular capillaries, across which ultrafiltration occurs