Kidney & Nephron Flashcards
Urinary Function Primary Function
Eliminates excess water, salts and metabolic waste in the form of urine
Removes nitrogenous waste and amino acids
Filters blood
Urinary System Homeostatic Functions
Regulates blood volume & pressure Regulates blood ion levels Stabilizes blood pH Removes drugs/toxins from blood Regulates red blood cell production
Organs of Urinary System
Kidneys Ureters Bladder Urethra Nerves & Muscles
Kidneys Location
Abdominal cavity
Retroperitoneal (posterior abdominal wall covered anteriorly by peritoneum)
Left slightly above (superior) right
Kidneys Protected by:
Visceral organs
Musculature of body and ribs
Fat
Kidneys Structure
Cortex - continuous - extends into renal columns Medulla - divided into pyramids - each pyramid ends in a papilla Pelvis - funnel-like -dilated
Kidney Features
- Fibrous capsule
- Renal cortex
- Renal column
- Renal medulla
- Renal pyramids
- Kidney lobe
- Minor calyx
- Major calyx
- Renal pelvis
- Hilum
- Ureter
Fibrous Capsule
Protective outer casing of kidneys
Renal Cortex
Superficial region containing renal corpuscles, blood vessels and collecting ducts
Renal Column
Medullary band of renal cortex between renal pyramids
Renal Medulla
Innermost part of kidney
Contains ‘loop of Henle’ and collecting ducts of nephrons
Renal Pyramids
Triangular sections of the renal medulla
Kidney Lobe
Consists of the renal pyramid, overlying area of renal cortex and adjacent renal columns
Minor Calyx
Collects urine produced by a single lobe
Major Calyx
Formed by the fusion of 4-5 calyces
Renal Pelvis
Collects urine from major calyces
Connected to the ureter
Hilum
Central fissure where blood vessels, nerves and the ureter pass
Ureter
Tube which drains urine form the renal pelvis to the bladder
Kidney Blood Supply TO the Cortex
Abdominal aorta -> renal artery -> small arteries -> afferent arteriole -> glomerulus
Kidney Blood Supply AWAY from the Cortex
Efferent arteriole -> cortical veins -> renal vein -> inferior vena cava
Kidney: Blood Filtration
Blood -> glomerulus -> filtrates (water, ions, nutrients, waste) -> waste to urine/reabsorption of molecules into blood
Nephron
- Renal corpuscle
- Proximal convoluted tube
- Descending limb of nephron loop
- Ascending limb of nephron loop
- Distal convoluted tube
- Collecting duct
- Papillary duct
Renal Corpuscle
Glomerular capsule
Glomerulus
Makes filtrate
Blood pressure forces water and dissolved solutes into capsular space
Proximal Convoluted Tube
Reabsorbs most of the nutrients
Reabsorption
Descending Limb of Nephron Loop
Reabsorption
Water is reabsorbed
Ascending Limb of Nephron Loop
Thick wall prevents water reabsorption
Reabsorption of sodium & chloride
Distal Convoluted Tube/Collecting Duct
Reabsorption of water and salt Under hormonal control Multiple nephrons drain into each duct Drain into minor calyces Concentrates urine
Anti-Diuretic Hormone
Released when the brain senses the body is dehydrated
Increases reabsorption of water
Acts on the distal convoluted tube and collecting duct
