M5 Renal Flashcards
What is the purpose of the renal system?
- regulate blood volume/pressure
- regulate water and solute balance
- filtration of blood
What is the renal system a part of?
Urinary system
What does the urinary system consist of?
Ureters - transport urine from kidneys to urinary bladder
Urinary bladder - temp storage of urine
Urethra - transporting urine out of body
Where are kidneys located?
Dorsally in lumbar vertebral region
What are the 5 major structures of the kidney?
Cortex - Outer
Medulla - spaces
Pelvis
Renal arteries and veins
Renal plexuses
What is filtrate?
Formed by kidney: blood plasma minus proteins
How much oxygen does the kidneys use?
20-25%
What does urine contain?
excess salts and metabolic wastes
How many times do kidneys filter the body’s entire plasma volume per day?
60
Path of blood flow through renal blood vessels
Aorta
renal artery
segmental artery
interlobar artery
arcuate artery
cortical radiate artery
afferent arteriole
glomerulus (capillaries)
efferent arteriole
peritubular capillaries or vasa recta
cortical radiate vein
arcuate vein
interlobar vein
renal vein
inferior vena cava
What are the nephrons
Network of tubules and vasculature across renal cortex and medulla through which filtrate is formed.
over 1 million nephrons per kidney.
What is the renal corpuscle?
Consists of glomerulus and glomerular capsule.
Efferent and afferent arterioles enter and lead to proximal convoluted tubule > nephron loop > distal convoluted tubule.
What is the glomerulus?
A ball of fenestrated capillaries
- highly porous, transporting large volumes of solute-rich,m protein-free fluid from the blood into the glomerular capsule. (some not others)
- Creates filtrate, processed by renal tubules to form urine.
What is the glomerular capsule?
Cup structure around glomerulus.
- external epithelium - simple squamous cells.
- visceral layer - attached to capillaries of the glomerulus.
(branching epithelial cells [podocytes] with filtration slits)
(Allows filtrate but not macromolecules to enter capsular space)
What is the purpose of renal tubules?
Reabsorption, secretion and urine formation
What are renal tubules?
Proximal and distal convoluted tubules, nephron loop.
- from renal cortex, into medulla and back to cortex)
- drains into collection ducts.
What is the purpose of collecting ducts?
site of water, sodium and acid-base balance maintenance.
What is the structure of proximal and distal convoluted tubule cells?
luminal surface (highly folded) lined by microvilli to increase surface area for water/solute reabsorption and secretion.
What is the structure of the nephron loop cells?
Thin-segment
What are the 2 cell types in the collecting duct?
Principle cells
- More numerous
- Fewer microvilli
- Water + Na+ balance
Intercalated cells
- More microvilli lining
- acid-base balance
(segmented alternating)
Does a single collecting duct receive filtrate from many nephrons?
Yes
Why does the renal pyramids have a stripy appearance?
side-by-side arrangement of collecting ducts.
What are the 2 types of nephrons?
Cortical - 85% of nephrons, situated in cortex, shallow tubules (proximal and distal)
Juxtamedullary - states at boundary, extend into medulla (only nephron)
What is glomerulus fed and drained by?
Afferent and efferent arterioles
- arrangement provides high-pressure blood supply to facilitate efficient filtration.