General Kidney/Urinary Bladder Flashcards
What are the functions of the renal system?
EXCRETION, water/electrolyte balance, pH regulation, control of circulating volume, hormone secretion, gluconeogenesis
What is the typical daily fluid intake?
2300 mL/day (ingestion of food/fluid + carb oxidation)
How do we lose body water?
Breathing, through our skin, sweating, feces, excretion by kidneys
What is the most common electrolyte disorder?
Hyponatremia
What is hyponatremia?
Low plasma sodium via dehydration or overhydration
What things could cause hyponatremia due to dehydration?
Diarrhea, vomiting, overuse of diuretics (overall loss of sodium chloride)
What could cause hyponatremia due to overhydration?
Abnormally high secretion of ADH
What serious conditions can result from hyponatremia?
Edema, brain swelling, brain damage, death
Why is it important to not induce rapid correction of hyponatremia?
Gradual correction is necessary to avoid further damage
What is hypernatremia?
High plasma sodium due to dehydration or overhydration
What are things that can cause hypernatremia due to dehydration?
Excessive sweating, lack of ADH production/sensitivity
How can hypernatremia be caused by overhydration?
Abnormally high secretion of aldosterone
In which scenario do effects tend to be more severe: hypo- or hypernatremia?
Hyponatremia
Why are the effects of hypernatremia less severe than hyponatremia?
Cells resist damage from shrinkage
Hyponatremia, metabolic depression, and lack of adequate nutrition can cause what kind of edema?
Intracellular edema
Fluid leakage and lymphedema (lymphatic failure) can can what kind of edema?
Extracellular edema
A person who is sweating profusely is at risk for: hypo- or hypernatremia?
Hypernatremia
Does someone with hyponatremia have very high or low levels of sodium in their blood plasma?
Low
When standing, the kidneys are located around what vertebral levels?
L1-L4 (in the retroperitoneal space)
Where is the base of the medulla located?
Cortical-medullary border
What is the tip of the medulla called?
Papilla
What structures contract to propel urine to the bladder?
Calyces, renal pelvis, and ureter
The kidneys make up about how much of cardiac output?
22%
What makes the renal blood flow so unique?
2 capillary beds separated by efferent arterioles (glomerular and peritubular capillaries)
Which set of renal capillaries has high hydrostatic pressure? Low?
High - Glomerular capillaries
Low - Peritubular capillaries
Which set of renal capillaries causes rapid fluid filtration? Which allows for rapid fluid reabsorption?
Fluid filtration - glomerular capillaries
Fluid reabsorption - peritubular capillaries
What is the functional unit of the kidney?
Nephron
What are the two different nephron structures/areas?
Cortical nephron, juxtamedullary nephron
Which nephron structure has a significantly longer Loop or Henle and penetrates deeper into the medulla?
Juxtamedullary nephron
Are new nephrons able to be regenerated by the kidneys?
No
After what age do we see a decrease in the number of functional nephrons?
40 (then 10% decrease every 10 years)
Where are glomerular capillaries encased?
In the Bowman’s capsule
What is the pathway of fluid being filtered from the glomerular capillaries?
Bowman’s capsule –> proximal tubule –> loop of Henle –> distal tubule –> connecting tubule –> collecting duct –> renal pelvis
Which structural type of nephron has a short loop of Henle and barely penetrates into the medulla?
Cortical nephron
Which are more common (70-80% of nephrons): cortical or juxtamedullary nephrons?
Cortical nephrons
What surrounds cortical nephrons?
Peritubular capillaries
What surrounds juxtamedullary nephrons?
Specialized peritubular capillaries called vasa recta
What kind of muscle makes up the urinary bladder?
Smooth muscle
What part of the bladder is where urine is collected?
Body
What part of the bladder attaches to the urethra and passes inferior and anterior from the body?
Neck
What is the name of the smooth muscle involved in emptying the bladder?
Detrusor muscle
Where is the trigone of the bladder located?
Posterior wall of the bladder
Where do the ureters enter the bladder?
At the upper trigone obliquely through the detrusor muscle
What is the difference between the surface of the trigone and the rest of the bladder walls?
Trigone = smooth mucosa Rest = folded rugae
What is the purpose of the tone of the detrusor muscle shutting down the ureters during micturition?
Prevents blackflow of urine
What muscle is located at the neck of the bladder?
Internal sphincter
What is the function of the internal sphincter?
Prevents emptying of the bladder until the pressure rises above the critical threshold
What is the internal sphincter composed of?
Detrusor muscle and elastic tissue
Which urethral sphincter is under voluntary control and made of smooth muscle?
External sphincter
What is the innervation of the urinary bladder?
Pelvic nerves through sacral plexus (S2-S3)
What kinds of fibers innervate the detrusor muscle?
Parasympathetic motor fibers
What kinds of fibers detect the stretch of the bladder wall?
Sensory fibers
What nerve innervates the external bladder sphincter?
Pudendal nerve (somatic nerve fibers)
What makes up the sympathetic innervation of the urinary bladder and what does it stimulate?
Hypogastric nerves (L2); stimulate blood supply to bladder
