Chapter 18: Urinary Flashcards
calyx
cup of flowers
detrudere
to push down
fenestra
window
glomus
ball
gonion
angle
juxta
near
papplillae
small, nipple-shaped projections
podon
foot
rectus
straight
ren
kidney
vasa
vessel
micturition
urination
position of kidneys
in peritoneal space; right sits lower than left
hilum
indented opening in the kidney where vessels enter and leave
renal sinus
internal cavity within the kidney
renal medulla
divided into 18 renal pyramids, the tips of which are called renal papillapyramids are divided by renal columns
minor calyx
cup-shaped drain into which each renal papilla discharges urine
major calyx
formed by four or five minor calyces; these combine to form the renal pelvis
renal pelvis
central collecting region in the kidney that flows into ureter
nephrons
functional units of the kidneysconsists of two main parts: renal corpuscle and renal tubulemay be cortical or juxtamedullary
afferent arterioles
deliver blood to capillaries supplying individual nephronshave greatest impact on controlling kidney blood pressure
efferent arteriole
small artery that carries blood away from the glomerulus to the peritubular capillaries
cortical nephrons
located mostly within cortex
juxtamedullary nephrons
located near the renal medulla; peritubular capillaries are connected to the vasa recta
renal corpuscle
consists of glomerulus and Bowman’s capsulein renal corpuscle, blood pressure forces fluid and dissolved solutes out of the glomerular capillaries and into the surrounding capsular space in a process called filtration
filtrate
protein-free solution produced by filtration at the renal corpuscle
renal tubule
microscopic tube in the kidney where urine is formed after filtrationmajor segments include: proximal convoluted tubule (PCT), loop of Henle, and distal convoluted tubule (DCT)
capsular space
space in-between the Bowman’s capsule and glomerulusreceives the filtrate and empties into the renal tubule
podocytes
specialized epithelial cells that cover glomerular capillaries; have long cellular processes called pedicels that wrap around
three layers of glomerular filtration membrane
•fenestrated pores of endothelial cells•fibers of basement membrane•filtration slits between the pedicels that wrap around the capillary
proximal convoluted tubule (PCT)
absorbs plasma proteins, water, vitamins, and ions from the tubular fluid
ascending limb of loop of henle
not permeable to water and solutes; actively transports sodium and chloride ions out of tubular fluidcreates concentration gradient in medulla, allowing kidneys to produce concentrated urine
descending limb of loop of henle
permeable to water; reabsorbs water
distal convoluted tubule (DCT)
reabsorption of sodium ions; secretion of acids, ammonia, and drugs
juxtaglomerular apparatus
made up of macula densa and juxtaglomerular cellssecretes EPO and renin
metabolic wastes of urine
urea, creatinine, uric acid, creatine phosphate
three processes of kidneys
filtration, reabsorption, secretion
filtration
occurs exclusively in the renal corpuscle, across the capillary walls of the glomerulus
reabsorption
occurs primarily at the PCT
active secretion
occurs primarily at the DCT; secretion is a selective, carrier-mediated process
filtration pressure
net force that promotes filtrationcaused by slight difference in the diameters of afferent and efferent arterioles
cardiac arrhythmias may occur if the extracellular concentration of ________ becomes too high
potassium
glomerular filtration rate is controlled by
•local automatic adjustments•sympathetic nervous system•various hormones
glomerular filtration rate (GFR)
amount of filtrate produced in the kidneys each minutegenerates about 180 L of filtrate per day (70x volume of plasma)
aldosterone
produced by adrenal cortex; occurs in response to lowered sodium concentrations of elevated potassium concentrations in the blood or to stimulation from angiotensin IIstimulates reabsorption of sodium ions/loss of potassium ions along DCT and collecting duct
antidiuretic hormone (ADH)
occurs under angiotensin II stimulationincreases permeability of DCT/collecting duct (stimulating increased water reabsorption at kidneys) and induces sensation of thirst
osmoreceptors
specialized hypothalamus neurons which can trigger release of ADH in response to low blood volume
renin-angiotensin system
if glomerular pressures fall, juxtaglomerular apparatus releases renin; renin converts angiotensinogen to angiotensin, which is then converted to angiotensin II
angiotensin II
causes vasoconstriction, elevates glomerular pressures, triggers release of ADH, and triggers secretion of aldosterone and epi/norepi by kidney
Atrial natriuretic peptide (ANP)
opposes actions of renin-angiotensin system; released by cardiac cells when blood volume and pressure are too highincreases sodium loss in urine, increases water loss, and inactivates renin-angiotensin system
ureteral openings
slitlike openings which prevents the backflow of urine into the ureters or kidneys when the bladder contracts
nephrolithiasis
kidney stonesmore frequent in the south, more frequent in men, commonly consist of calcium salts
umbilical ligaments
peritoneal folds that extend to the umbilicus that hold the urinary bladder in place
trigone
triangular area in the urinary bladder bounded by the ureteral openings and the entrance to the urethra
internal urethral sphincter
smooth muscle; involuntary control over discharge of urine
detrusor muscle
the smooth muscle layers of the bladder; contraction compresses bladder and expels contents into the urethra
external urethral sphincter
skeletal muscle, voluntary
urinary tract infections (UTIs)
almost all UTIs start with pathogenic colonization of the bladder by bacteria that enter through the urethra; therefore, females are at higher risk because they have shorter urethrasE. Coli accounts for roughly 80% of infections
pyelonephritis
inflammation of the renal pelvis and the kidney
fluid balance
because your cells and tissues cannot transport water, fluid balance primarily reflects the creation of ion concentration gradients that are then eliminated by osmosis
electrolyte balance
neither a net gain nor loss in any ion in body fluids; primarily involves balancing the rates of absorption across the digestive tract with rates of loss at the kidneys
acid-base balance
production of hydrogen ions is equal to their loss
importance of fluid/electrolyte/acid base balance
treatment of any serious illness that affects the nervous, cardiovascular, respiratory, urinary, or digestive systems must always include steps to restore normal fluid, electrolyte, and acid-base balance
sodium balance
kidneys are most important sites for regulating sodium ion lossesindividuals with high BP are told to restrict salt intake because “water follows salt”–water leaves cells and enters extracellular fluids, raising BP
potassium balance
roughly 98% of K+ content lies within intracellular fluidrate of gain is proportional to the amount of potassium in the diet; aldosterone strongly affects the rate of loss
acidosis
blood pH below 7.35severe alkalosis can lead to: CNS function deterioration, weak cardiac contractions, and peripheral vasodilation
alkalosis
pH above 7.45
most important factor affecting pH in body tissues
carbon dioxide concentration
buffer system
Consists of a combination of weak acid and its dissociation products: a hydrogen ion and an anion
three major buffer systems of the body
protein, carbonic acid-bicarbonate, and phosphate
protein buffer systems
contribute to regulation of pH in both ECF and ICF; depend on ability of amino acids to respond in changes in pHplasma proteins and hemoglobin in RBC contribute to buffering capabilities of the blood
carbonic acid-bicarbonate buffer system
important buffer system in the ECFprevents pH changes caused by metabolic acids; mobilizes bicarbonate reserve to convert H+ ions from carbonic acid into CO2 and H2O (CO2 is then exhaled at the lungs)
phosphate buffer system
buffers pH of ICF (where concentration of phosphate ions is high)
respiratory compensation
change in respiratory rate that helps stabilize the pH of the ECFwhen the PCO2 rises, the pH declines (and vice-versa)
renal compensation
a change in the rates of hydrogen ion and bicarbonate ion secretion or absorption in the kidneys in response to changes in plasma pH
urinary retention
may develop in males in response to enlargement of the prostate gland; swelling and distortion of the prostatic tissues compress the urethra, and restrict or prevent the flow of urine
respiratory acidosis
generally caused by hypoventilation and CO2 buildup in tissues and blood
metabolic acidosis
caused by buildup of metabolic acid, impaired H+ excretion at kidneys, or bicarbonate loss in urine or feces
respiratory alkalosis
generally caused by hyperventilation and reduction in plasma CO2 levels
metabolic alkalosis
usually caused by prolonged vomiting and associated acid loss
