Kidney Anatomy and Physiology

Anatomy Introduction - Kidney

• Kidneys filter waste from blood, which originates from every cell
• Nephrons in the kidneys perform blood-filtering and produce urine
• Cortex contains the filtering units
• Medulla contains pyramids and calyxes
• Renal pelvis collects urine before transport to the ureter
• Ureter connects the kidneys to the bladder
• Renal artery delivers blood from the aorta to the kidney
• Renal vein returns filtered blood to the heart
• An adult produces 6 cups of urine per day on average
• Kidneys contain 1 million nephrons each
• Kidneys are dark red because they are filled with blood
• Medulla consists of pyramids and calyxes

Anatomy Conclusion

• Bladder stores urine until disposal
• The bladder can hold 2 cups of urine
• The bladder is surrounded by smooth muscle
• Sphincter muscle helps in urine retention
• Urethra is a tube-like structure that transports the urine out

Physiology Introduction

• Renal arteries transport blood to the kidneys
• Kidneys filter waste, water, and other nutrients from the blood
• Homeostasis is the reabsorption of water and other nutrients back into the bloodstream
• Homeostasis keeps the internal environment of the body stable
• Every 4 minutes, kidneys filter 1 gallon of blood (425 gallons/day)
• If a person has 5 liters of blood, it gets cleaned 327 times a day

Physiology Conclusion

• Bladder stores urine until it can be expelled
• Ascending nerves from the bladder communicate "I'm full" to the brain
• The brain uses descending nerve tracks to communicate back to the bladder

Common Ailments Introduction

• Four common ailments of the urinary system are urinary tract infection, renal failure, kidney stones, and glomerulonephritis

Urinary Tract Infections

• UTIs are bacterial infections anywhere in the urinary tract
• Antibiotics slow down bacteria growth
• Females are more likely to contract UTIs due to shorter urethras
• UTIs are most common in the bladder, also called a bladder infection
• 8 million out of 350 million Americans get UTIs every year
• 1/5 women will get a UTI in their lifetime
• The cause is bacteria entering the urinary tract, often the urethra
• Causes in females include improper wiping
• Causes in males include the tip of the penis not being cleaned well
• Sterile means there is no living bacteria present
• Symptoms vary depending on the source of the infection
• Symptoms include painful urination, cloudy urine, and frequent urination
• Treatment is antibiotics and usually clears within about two weeks

Renal Failure

• This is also called kidney failure
• Filtering of blood by the kidneys is either slowed or stopped
• If your kidneys no longer function, you can only live 7 days
• Waste products build up in the blood
• Acute renal failure is sudden and reversible
• Swelling, is typically a 3 day event
• Acute renal failure may be due to bacterial infection, injury, shock, heart failure, poisoning, or drug overdose
• Treatment for Acute renal failure includes dialysis or surgery
• Chronic renal failure is when kidneys lose function over time
• If diagnosed early, Chronic renal failure can be treated but not reversed
• Chronic renal failure usually requires a kidney transplant
• Chronic renal failure can come from diabetes or alcohol abuse
• Dialysis is when a machine removes wastes outside the body daily
• Kidney transplant requires a donor, but only one kidney is needed

Kidney Stones

• Kidney stones are hard pebble-like obstructions in the urinary tract
• Kidney stones are a buildup of crystallized salts and minerals like calcium in the urinary tract
• Kidney stones are hard, and get stuck in the urinary track
• Kidney Stones form after recurrent urinary tract infections
• Kidney Stones form after drinking too little fluid
• Kidney Stones form due to a blockage of the urinary tract
• Limited activity for several weeks or more while passing
• Consuming too much calcium oxalate or uric acid can cause kidney stones
• Consuming too much vitamin C or D can cause kidney stones
• They are only detectable by x-ray

Four basic treatments:

• Small stones will pass, and can use pain meds if needed (must be less than 6mm across)
• If still in the kidney, lithotripsy uses powerful waves to vibrate stones apart
• Protect Doctors ears when completing procedure
• If stuck in the ureter, use a laser blast with stint
• If it is too massive, surgery can be used to cut it out through the back

Glomerulonephritis

• Also called Nephritis
• Tiny filters in the kidney that help to clean the blood get inflamed or damaged
• Glomerulo refers to glomerulus, nephr refers to nephron, and itis refers to swelling
• Causes include infection, certain drugs, cancer but most often it is unknown
• Glomerulus is the globe part of the nephron, bringing wastes and good stuff into the nephron
• The Loop of Henle puts good stuff back into the blood
• Urine exits the Loop of Henle into pyramids
• This causes swelling of the glomerulus, so the whole process doesn't work well
• Glomerulonephritis, is very treatable if found, and often doesn't need treatment
• Glomerulonephritis if untreated, may slowly destroy your body
• Glomerulonephritis can lead to a loss of a kidney if not discovered
• Symptoms include high blood pressure, excessive foaming of urine, or urine that changes color (to red or brown)
• Symptoms include puffiness of extremities, vomiting, difficulty breathing, or headaches