N715 Exam 3 New Pt 3

Kidney Structure and Function

• The basement membrane lines the endothelium, with immune response processes.
• Mesangial cells help regulate sodium while protecting the kidneys from damage.
• Glomerular filtrate is plasma without plasma proteins (albumin).
• The glomerulus and basement membrane are crucial for homeostasis.
• Glomerular capsules enter nephrons, some shorter and found in the cortex.
• Nephrons that are bigger and longer are found deeper in the medulla, and have a larger surface area for reabsorbing sodium chloride, and water.
• The final glomerular filtrate becomes urine after passing through collecting ducts, renal pelvis, and ureters for eventual bladder storage.
• The juxtaglomerular apparatus allows filtered substances to re-enter the vascular system.

Glomerular Filtration and Loop of Henle

• Glomerular filtration in the descending loop of Henle causes rapid water reabsorption, increasing osmolality from very dilute to very thick.
• The maximum osmolality of filtrate in the loop of Henle is 1200 millimoles.
• Reabsorption of sodium chloride and the elimination of waste products takes place at this point, decreasing osmolality.

Acute Kidney Injury (AKI)

• Prerenal AKI is due to poor blood flow to the kidneys.
• Intrinsic AKI is due to damage within the kidneys. This may be due to inflammation, infections, or other issues in the glomeruli, tubules, or interstitial tissue.
• Postrenal AKI is due to obstructions in the urinary tract.

Ureters

• Ureteropelvic junction (UPJ) is the junction between the renal pelvis and the proximal ureter.
• The pelvic brim is where iliac blood vessels cross over the ureter.
• The ureterovesical junction (UVJ) is where the ureter enters the bladder.
• Urine moves downward due to peristalsis and gravity.

BUN/Creatinine Ratio

• Normal BUN/creatinine ratio is 10-20 to 1.
• Creatinine is another nitrogenous product of the body.
• Pre-renal issues, like reduced kidney perfusion, can lead to a rise in the BUN/creatinine ratio.
• Post-renal issues, like obstructions, can also lead to a rise.
• A decrease in the BUN/creatinine ratio may indicate renal problems.

Glomerulonephritis

• Glomerulonephritis is a type of kidney disorder that causes inflammation of the glomeruli.
• Different types of glomerulonephritis can cause different issues.
• Clinical manifestations of glomerulonephritis can vary depending on the specific type or presence of associated diseases.
• Causes include autoimmune conditions and infections (infective, genetic, metabolic, ischemic).

Renal Function

• Kidneys remove waste products, like urea, creatinine, uric acid, and drugs.
• They maintain acid-base balance, water balance, electrolyte levels, and remove toxins.
• Kidneys produce erythropoietin for red blood cell production and activate vitamin D.

Urine Analysis

• Key elements of urinalysis include color, clarity, specific gravity, the presence of blood, protein, glucose, and bacteria.
• Abnormal results may suggest certain renal or urinary issues.

Renal Function in Aging

• By age 40, kidney function can decrease by 10% per decade.
• This is partly due to the loss of glomeruli in the kidneys.
• There are also changes to the structures of tubules and loops of Henle.

Kidney Stones

• Kidney stones are deposits of minerals and salts.
• Different types of stones are most common, including calcium stones, uric acid stones, and struvite stones.
• Formation of stones can be affected by levels of calcium, pH in urine, hydration, diet, and more.
• Clinical manifestations can include acute onset of abdominal pain, with symptoms of blood in urine/hematuria and pain that may change location or severity.

Hormone Function and Transportation

• Many hormones are transported unbound.
• Lipid-soluble hormones travel through the blood with carrier proteins, while water-soluble hormones travel freely.
• Different hormone actions result in different effects based on their properties. Hormone receptors play a vital role in these interactions.

Positive and Negative Feedback Loops

• There are positive feedback loops that are present throughout the various body systems.
• Negative feedback loops regulate hormone levels and maintain homeostasis.