Chapter 11: The Urinary System Flashcards
What’s the primary function of the urinary system?
Regulate extracellular fluids of the body (plasma and tissue fluid).
Define electrolyte:
Mineral salt of the body that carries an electrical charge and regulates nerve impulses, muscle contractions, hydration, and blood pH.
Define filtrate:
Fluid that passes from the blood through the capillary walls of the glomeruli to the Bowman capsule. Urine is formed from filtrate, which is similar to plasma with less protein.
Define nitrogenous waste:
Product of protein metabolism that includes urea, uric acid, creatine, creatinine, and ammonia.
Define peristaltic wave:
Sequence of rhythmic contractions of smooth muscles of a hollow organ to force material forward and prevent backflow.
Define peritoneum:
Serous membrane that lines the abdominopelvic cavity and covers most of the organs within the cavity.
Define pH:
Symbol that expresses the acidity or alkalinity of a solution. [acidic < 7 (neutral) < alkaline]
Define plasma:
Liquid portion of blood filtered by nephrons to remove dissolved waste.
What happens if the kidneys do not continuously remove wastes?
Death
What is erythropoietin?
Produced by the kidneys that stimulates RBC production in bone marrow when O2 levels are low.
Tell me about the kidneys:
Each are about the size of a fist, bean-shaped, and are retroperitoneal. In a cross-section view, they have an outer renal cortex and inner renal medulla.
Renal cortex
Outer layer of the kidneys (in a cross-section view)
Renal medulla
Inner layer of the kidneys (in a cross section view)
Nephrons
Microscopic filtering units of the kidneys.
Hilum (singular hilus)
An opening near the medial border of the kidneys through which the renal artery enters and the renal vein exits.
Renal pelvis
Hollow cavity where the ureter merges with the kidney.
Tell me about the ureters:
Each is ~10”-12” long; these carry urine in peristaltic waves to the bladder.
What is the urethral orfice?
Where the ureters meet the urinary bladder.
Tell me about the urinary bladder:
It’s an expandable, hollow organ that acts as a temporary reservoir for urine. It has small folds called rugae that expand as the bladder fills.
What’s the trigone?
Triangular area at the base of the bladder formed by the openings of the ureters and urethra; leads into the urethra.
Tell me about the urethra:
Tube that discharges urine from the bladder. ~1.5” in women and ~7-8” in men. In males, the urethra passes through the prostate gland and the penis.
What’s micturition?
urination
What’s the urinary meatus?
Opening in the urethra through which urine is excreted from the body.
About how many nephrons are there in a kidney?
1 million