Lab 6 Flashcards
What is the primary function of the urinary system?
Produces urine that removes metabolic wastes and toxins
What is a secondary function of the urinary system?
Maintain homeostasis by conserving glucose, water, and electrolytes
What happens when there is urinary dysfunction?
Disrupts homeostasis and is ultimately fatal
How many kidneys are there in the human body?
2
What is the anatomical position of the kidneys?
Retroperitoneal; positioned behind the abdominal cavity
Which kidney is lower than the other and why?
The right kidney is lower due to the dominance of the liver on the right
What is the function of the ureters?
Transports urine from kidneys to bladder
What mechanisms are involved in the transport of urine through the ureters?
Peristalsis, hydrostatic pressure, and gravity
What is the primary role of the urinary bladder?
Stores urine
What is the average length of the male urethra?
~20 cm long
What is the average length of the female urethra?
~3.5 cm long
What is the trigone in the urinary bladder?
The floor of the bladder with openings for the ureters and urethra
What type of muscle is the internal urethral sphincter?
Smooth muscle (involuntary)
What type of muscle is the external urethral sphincter?
Skeletal muscle (voluntary)
What are rugae in the urinary bladder?
Folds in the mucus membrane that smooth out when the bladder is full
What is the nephron?
The functional unit of the kidney where urine is formed
What are the components of the nephron?
Renal corpuscle, glomerulus, glomerular capsule (Bowman’s capsule), renal tubule
What is the function of the proximal convoluted tubule?
Reabsorbs water and other substances back into the blood
What is the function of the distal convoluted tubule?
Fine-tunes electrolyte balance, reabsorbs sodium/calcium, and secretes potassium and hydrogen
What is the role of the nephron loop (loop of Henle)?
Concentrates urine by reabsorbing water and sodium/chloride
What is the collecting duct’s function?
Receives filtrate from several nephrons and empties into a papillary duct
What percentage of nephrons are cortical nephrons?
80-85%
What percentage of nephrons are juxtamedullary nephrons?
15-20%
What are the two capillary beds that supply the nephron?
Afferent arteriole and peritubular capillary bed
What is the function of peritubular capillaries?
Reclaims most of the glomerular filtrate
What does an intravenous pyelogram (IVP) involve?
IV dye with X-ray to assess kidney issues
What is the flow of filtrate and urine from the nephron?
Nephron → collecting duct → papillary duct → minor calyx → major calyx → renal pelvis → ureter → urinary bladder
What are the main functions of the nephron and collecting duct?
Filtration, reabsorption, secretion
What is Net Filtration Pressure (NFP)?
The force that moves fluid across the glomerular capillaries
What is Glomerular Hydrostatic Pressure (GHP)?
Blood pressure in glomerular capillaries that forces fluid out
What does Blood Colloid Osmotic Pressure (BCOP) do?
Forces fluid back into the glomerular capillaries
What substances are primarily reabsorbed in the nephron?
*Water
*Glucose
*Amino acids
*Ions
What substances are primarily secreted in the nephron?
*Metabolic wastes
*Drugs
*Ions
What is the normal content of urine?
*95% water
*5% solutes
What is urochrome?
A pigment from hemoglobin breakdown that affects urine color
What does the turbidity of urine indicate?
Cloudiness; could suggest infection or other issues
What is the specific gravity range for normal urine?
1.003 to 1.030
What factors can affect urine pH?
*Diet
*Infection
What are common causes of abnormal urine contents?
*Kidney stones
*Blood cells
*Microbes
What are kidney stones composed of?
Mineral salt crystals that precipitate out of solution
What can cause hematuria?
Blood in urine due to various conditions
What does urinalysis involve?
Analysis of urine to disclose evidence of disease
What is the purpose of a urine culture?
Confirms diagnosis and identifies bacteria causing infection
What does macroscopic urinalysis include?
Direct visual observation of urine quantity, color, clarity
What can cause orange urine?
Bile pigments or Pyridium
What factors can cause red urine?
*Hematuria
*Beets
*Blackberries
What does urine test strip measure?
*Specific gravity
*pH
*Glucose
*Protein
*Ketones
*Leukocyte
*Nitrite
*Bilirubin
*Urobilinogen
What is a disadvantage of urine test strips?
Not very accurate and time sensitive
What does the presence of leukocytes in urine indicate?
Possible infection
What do elevated ketones in urine suggest?
Accumulation in plasma, often related to diabetes
What does the presence of bilirubin in urine indicate?
Possible liver disease
What might the presence of epithelial cells in urine suggest?
Inflammation or contamination
What can evidence of WBC or bacteria in urine suggest?
Possible urinary tract infection
