Urinal system 1 Flashcards
Kidney Anatomy
• Surfaces – Anterior (renal artery/vein above) & posterior (ureter is above)
• Margins – Lateral (greater curvature) & medial (lesser curvature)
• Poles – Superior & inferior
o Superior pole is protected by lower ribs
o Inferior pole is protected by layers of connective tissue & fat
Right Kidney
o Lower than left kidney because during development, the liver pushes it downwards
o The same side as the inferior vena cava
o Right renal artery is longer
o Related to liver, duodenum & ascending colon
▪ Note: “” = separated by peritoneal membranes
Left Kidney
o Same side as the aorta Left renal artery is shorter
o Related to stomach, spleen, pancreas, jejunum* &
descending colon
kidney cortex
takes up the outer 1/3 of the kidney
kidney medulla
takes up the inner 2/3 of the kidney
Kidneys – Support
• Renal capsule o Innermost layer attached to surface of kidney o Protects kidney • Adipose capsule (Perinephric Fat) o Protective mass of fatty tissue o Cushioning function • Renal fascia o Dense irregular connective tissue o Anchors kidney and adrenals in abdomen • Paranephric fat o Outside of renal capsule
Kidney Blood Supply
abdominal aorta, after the superior mesentery artery,
two bilateral branches come off to give rise to the renal arteries
Because the left kidney is located closer to the aorta, the left renal artery is much shorter than the right renal artery.
However, the right kidney is closer to the inferior vena cava, so the right renal vein is shorter than the left renal vein.
Venous Drainage kidney
o Nephron -> Interlobular vein (cortical radiate vein) -> Arcuate Vein -> Interlobar vein -> Renal vein
o The arcuate veins (and arteries) separate the kidney cortex from the kidney medulla
o Interlobar veins separate the lobe of the kidneys by running through them.
Arterial Supply
o Renal artery -> Segmental arteries -> Lobar arteries -> interlobar arteries -> arcuate arteries -> interlobular arteries -> nephron
Renal corpuscle
area where filtration occurs
o Contains the glomerulus within the bowman’s capsule
Podocytes
are present and have slits between their projections so that filtration will occur
o Continuous with epithelial layer of bowman’s capsule
Uriniferous tubule
nephrons + collecting duct
o One million per kidney
o Collecting ducts are present in the thousands which give the renal pyramids the striated look
Cortical Nephrons
o 85% of all nephrons
o Almost entirely in cortex
o Peritubular capillaries from efferent arterioles
Juxtamedullary Nephrons
o 15% of all nephrons o At cortex-medulla interface o Loops invade deep into medulla o Descending limb more extensive o Involved in forming concentrated urine o Vasa recta = cross-bridging capillaries
Polycystic Kidney Disease
- Autosomal dominant trait (i.e. genetic cause)
- Single or multiple cysts
- Important cause of renal failure
3 points of constriction (kidney stones)
ureteropelvic junction
pelvic inlet
entrance to bladder
Ureters
Duct draining the renal pelvis to the bladder
retroperitoneal
enters bladder at a sharp angle working as a natural valve
Pyelography
intravenous or retrograde injection through urethra
visualizes calices, ureter and bladder.
Urinary bladder
muscular sac to store urine
detrusor muscle under autonomic control
Urinary bladder anatomy
ureter rugae ureteric orifices bladder neck trigone - void of regae
Micturition reflex
- visceral stretch afferents synapse in sacral spinal cord
- coordination by the pontine micturition center stimulates efferent limb
- pelvic splanchnic n. contract the detrustor
- Lumbar sympathetic to bladder are inhibited to relax the internal urethral sphincter
- voluntary inhibition of the pudendal n. relaxes the external urethra sphincter
Incontinence
leaky bladder
urethral slings to prevent stress incontinence
attached anteriorly
wraps around bladder neck to act as another sphincter
