module 7 urinary system Flashcards
What are the primary organs of the urinary system
2 kidneys, 2 ureters, 1 bladder, 1 urethra
ureter drains from what and into what
from kidney; into urinary bladder
what is the function of the kidney
fluid homeostasis, filtrate waste, blood volume homeostasis and the chemical composition of blood
what is the shape of the kidney
bean, size of soup can, 5oz,
where is the kidney located
R is lower than L because of liver as it lies between T12 and L3
Where is the renal hilus and what enters
medial surface of kidney: concave:
ureter, blood vessel and nerves enter in the hilus and leads to interior sinus
What is the renal sinus
space just inside the kidney- hilus leads to it
what are the 3 specialized tissues in the kidney
inner: renal capsule: tough fibrous outer: protect from injury and infection
2. adipose capsule: fatty layer outside renal protect from trauma
outer: renal fascia: dense fibrous connective tissue keeps kidney connected in abdominal cavity
What are the 3 regions of the kidney
renal cortex, renal medulla, renal pelvis
Describe the renal cortex
just inside renal capsule: continuous outer region with several cortical columns extend down between pyramids
what is in the renal cortex
glomular capsule and distal/proximal tubule section of nephron along with associated blood vessels
Describe the renal medulla
deep in kidney
divided into pyramids
What is in the renal medulla
Loop of henle and collecting ducts
sections of nephron w/associated blood vessels
Describe the renal pelvis
centermost section of kidney
funnel shaped tube connects to ureter as leaves hilus
ureter transports to bladder to be stored
What are the extensions of the renal pelvis called and their function
Calyces: collect urine
What is the blood pathway of the renal arteries and their branches to afferent arteriole
renal artery->segmental->lobar->interlobar artery->arcuate artery->interlobular artery->afferent artery-supplies glomerular capillaries
What is the blood pathway of renal vein after filtration
filtration->efferent arterioles->peritubular or vasa recta capillaries->interlobular vein->arcuate vein->interlobar vein->renal vein
what is the renal plexus
it is how the kidney and nervous system interact
fibers follow renal arteries to kidneys
what system adjusts the diameter of renal artery there regulating the renal blood flow
input from sympathetic nervous system
describe ureter and its function
thin muscular tube; carry urine from kidney to bladder; begins as a continuation of renal pelvis
what are the ureterovesical valves and what do they prevent
sphincters located where ureter enter bladder
help prevent urine back flow toward kidney
what are the 3 tissue layers of the wall of the ureter
inner: transitional epithelium
middle muscular : 2 sheets: 1 longitudinal and other circular
outer: adventitia: fibrous connective tissue
distention of which layer of the ureter causes contraction to push urine through
middle muscular layer
Describe the bladder
hollow, muscular, elastic pouch: receives and stores urine
where is the bladder located in males? females
males: base of bladder in front of rectum, behind pubic symphysis
female: below uterus, in front of vagina, max capacity is lower in females
where does the ureter open into the bladder
uretal orifice
what begins at the base of the bladder
urethra
what is the opening called that is triangular shaped in bladder and is smooth
trigone
what are the 3 tissues of the bladder wall
outer: adventitia: fibrous connective
middle: muscular detrusor muscle- inner and outer longitudinal layer
inner: mucosal: transitional epithelium
Describe the bladder when its empty
when full
when empty: collapses into a pyramid shape because of the elasticity
when filling: swells into pear shape and rises in abdomen cavity; muscular wall stretches, rugae extend to help capacity of bladder
how much urine can bladder hold
moderately full: 500mL of urine
capacity is 1000mL
Describe the urethra
thin wall tube carry urine from urinary bladder out of body
mucosal lining of urethra start as transitional cells as exit bladder come stratified columnar and then stratified squamous cells near external urethral spinctor
Describe the internal urethral spinctor
involuntary controlled: located near bladder and keep urethra closed to prevent urine from leaving bladder
Describe external urethral sphinctor
voluntary controlled: composed of skeletal muscle, surround uretrha as pass through pelvic floor
what are the differences in the urethra between males and females
female: urethra is shorter, only carries urine
male: 5x longer, carry both urine and semen from body- functions only 1 system at a time
what are the 3 regions of the male urethra
prostatic: run with prostate
membranous: run with urogenital diaphragm
spongy: run w/in penis: opens to external urethral opening
What is a UTI
Urinary Tract Infection
female urethra is short and external opening is close to anus
poor hygiene after defection can easily carry fecal bacteria into urethra- bacteria enter and travel to bladder causes UTI
What is the nephron
structural and functional unit of the kidney
over 1,000,000
What is the function of the nephron
control concentration of water and solutes in blood
reabsorb needed material
excrete rest as urine- eliminates waste, regulates: blood volume, pH, pressure and controls electrolyte balance
what are the 2 parts of the nephron and how are they connected
glomerular capsule: filters blood
renal tubule: reabsorb needed material+ collecting duct carry remaining material away as urine
2 parts are connected by tubule and collecting ducts
what are the 3 parts of the renal tubule
proximal convoluted tubule: PCT
loop of henle
distal convoluted tubule: DCT
What is the renal corpuscle
composed of glomerulus
what is the glomerulus
network of tiny blood capillaries surrounded by glomerular( Bowmen) capsule(double walled squamous epithelial cup)
what do the glomular capillaries lie inbetween
the afferent and efferent arterioles
describe the afferent arteriole
fed by interlobular artery, larger than efferent
the difference in diameter causes increase in BP in glomerular capillaries: force H20 and solutes out of blood making filtration possible
What is filtrate
H20 and solutes that have left the blood and entered glomerular capsule
What is a cortical nephron and what % of kidney is the nephron
85%
found in cortex region of kidney
small portion in loop of henle which goes into medulla
what are juxtamedullary nephrons
remaining 15% of nephrons in the kidney
pass deeply into medulla because of location and longer loop of henle
Describe the PCT structure and function
surrounds renal tube+ secrete unwanted substance
reabsorbs H20 and solutes from glomerular filtrate into decreased pressure peritubular capillaries
Describe the Loop of Henle
has 2 limbs: ascending and descending( ascending is first)
descending allow H20 loss
ascending allow NaCL loss
Describe the DCT
allow for hormonally control reabsorption of water and solutes
secretes unwanted substances
when is filtrate considered urine
when reaches renal pelvis
what is the collecting duct
urine drains into this duct after passing through tubulues
what are the papillary ducts
many collecting ducts form this
drain into calyces and subsequently into renal pelvis and out of kidney by what of ureter
Describe the glomerular capillaries
highly coiled, formed from afferent arterioles, leaving as efferent arteriole
specialized for filtration: force fluid and solute out of blood and into glomular capsule
99% of glomular filtrate reabsorbed through renal tubule and return to blood in peritubular capillary bed
Describe Peritubular capillaries
closely follow renal tubules- drain into interlobular vein
adapted for absorption, reclaim H20 and solute from filtrate because of decreased pressure
Describe the Vasa Recta
follows loop of Henle in juxtamedulllary nephron of medulla
what is micturition
urination: empty bladder
what is the process for urination
urge felt at about 200mL of liquid- cause bladder wall to distend, intitiate visceral reflex arc-> detrursor muscle contracts and internal sphincter relaxes, force stored during through internal sphincter into urethra to be expelled
which sphincter can be ignored
external as it is voluntary
if reaches 100% capacity- external sphincter becomes involuntary
define incontinence
inability to control urination voluntarily
normal in infants and later in life/dementia
nervous system injury/stroke
define urinary retention
inability to expel stored urine
common after general anesthesia
in males occurs dur to overgrowth of prostate
catheters may be necessary to insert in urethra to allow bladder to empty
how many times a day do kidneys filter entire blood plasma
how much of resting energy is used for this process
60x/day
25% of resting energy
how many gallons of glomerular filtrate contain H20, nutrients and ions are removed daily
47 gallons
by the time filtrate enters collecting ducts how much is actually urine
.5 gallon
other 99% is returned to blood
what 3 processes happen for body to filter all blood and return important elements
filtration: glomerulus
reabsorption: renal tubules
secretion: renal tubules
Describe glomerular filtration
mechanical: no energy required
takes place across porous membrane- lie between capillaries and interior glomerular casuple
depends on opposing pressure exerted w/in glomerular capsule and glomerulus capillary
measured in mmHg: milimeters of mercury
What is HP in glomerular filtration
Hydrostatic pressure of blood
amount found inside the blood in capillaries:
drives fluid out of capillaries
varies from person to person, dependent on BP from heart and vessels
What is Colloid Osmotic Pressure( COP)
oncotic pressure
dependent on # of protein in plasma
opposes blood HP by drive fluid back into capillary bed
draws H20 out of filtrate
What is normal range for COP and what happens if out of range
normal range 25-32mmHG
if out of this range causes damage to glomerulus
What is Capsular Hydrostatic pressure
mechanical pressure exerted by recoil of elasticity inside glomerular arteriole
opposes blood HP by driving fluid back into glomerular capillaries
What is Net filtration Pressure
difference in pressure between outgoing and incoming forces at glomerulus
pressure which filtrate enter the PCT
What is the glomerular filtration rate( GFR)
amount of blood filtered by glomerulus over time
what is normal GFR rate
120-125mL/min or 180L/day
due to surface area glomerular artery, large degree filtration membrane permeability and moderate net filtration pressure
What causes and increase/decrease in GFR and why is constant rate importatn
increase in GFR caused by increase arterial BP in kidney
decrease in GFR caused by increase in glomerular osmotic pressure: dehydration normal cause
maintenance important: adequate reabsorption H20 and other substances from filtrate and filtering of wastes
what is the result if GFR is too fast or too slow
too fast: substance are not adequately reabsorbed
too slow: nearly all filtrate reabsorbed: including wastes
What are the 3 mechanisms that regulate GFR
Renal autoregulation
nervous system
Hormonal: Renin-angiotensin-aldosterone: RAA
Describe renal autoregulation
kidney determines own rate of blood flow by controlling diameter of afferent and efferent arterioles
able to maintain constant GFR despite change in arterial BP in rest of body
Describe how the nervous system regulate GFR
takes over in times of emergencies
afferent arteriole diameter narrowed by sympathetic fibers
releases epinephrine: decrease renal blood flow and decrease GFR
long periods of time with decreased blood to cell of kidney is damaging to kidneys
when does RAA respond
when body BP is too low
what is angiotensiongen
pre-enzyme: produced by liver: freely circulates blood
what is renin
enzyme released by juxtaglomerular cell of nephron when BP drops
How does RAA work
when renin is released, it causes constriction of efferent and afferent arterioles and signals angiotensiogen to be converted to angiotensin 1
in the lungs: angiotensin 1 is converted to angiotensin 2 signaling thirst in hypothalamus
water intake increase BP and blood volume
angiotensin 2 causes vasoconstriction to increase peripheral BP
angiotensin 2 reaches adrenal cortex and aldosterone is released
aldosterone cause renal tubules to absorb more NaCL- increasing water retention
overall helps in reabsorption of water and sodium from filtrate
What is tubular reabsorption
process of fluid and substances moving from filtrate back into blood
If tubular reabsorption didn’t occur-entire plasma drained away as urine in 1 hour
hormonally regulated; active or passive
what is diffusion and is it active or passive
process that does not require energy and passive
active means: pumps ATP driven and require energy
where is the greatest amount of tubular reabsorption occur
in cells of PCT
What substances are actively reabsorbed in PCT
glucose and amino acids
65% of Na+, 65% H2O, 90% HCO3-, 50% chloride, 50% K+ reclaimed from filtrate along with most ca, phosphate and magnesium
How do the ascending and descending loops act differently from each other in loop of henle
H2O leaves descending but not ascending
Na+ and K+ leave ascending but not descending
What is reabsorbed in loop of henle
25% Na, 15% H20, 40% K, reabsorbed in pertubular capillaries to return to blood
How much of various filtrates remain after being filtered in PCT and loop of Henle and in DCT
10% of Na and CL, 20% H20 remain once reaching DCT
what conditions can be controlled by ions channelled through DCT and collecting ducts
abnormal BP, low blood volume, low Na+ or high K+ in fluid
What is tubular secretion
removing substances from peritubular capillaries
What regulates urine concentration and volume
kidneys: they maintain homeostasis
What is countercurrent flow
movement of fluids in opposite direction through adjacent channels
ex: filtrate in nephron flows in 1 direction through renal tubules while blood in adjacent flows in opposite direction
what is the purpose of the countercurrent flow
help kidney to establish and maintain osmotic gradient from renal cortex to medulla
what is the osmotic gradient
concentration of solutes inside a solution measure in milliosmoles/liters
what does isomotic mean
fluid inside/outside have same concentration
osmotic characteristic of filtrate when entering PCT is
300
when does solute concentration increase
in descending limb of loop of henle: hair pin turn filtrate increase 1200 mOsm/L
what is urea
substance converted from ammonia to be excreted as urine
where is the concentration of urea high
where is the concentration of urea lower
in DCT and cortex of collecting ducts because tubules in cortex are impermeable to it: high
medullary collecting duct as it is highly permeable to it- contributes to high osmolarity until concentrations are equal inside/out of duct
What is ADH and its function
hormone produced in hypothalamus and released posterior pituitary
inhibits urine output by increasing # of channels in cells o collecting ducts
connected to body degree of hydration
responds to hemorrhage
which factors contribute to dehydration
excessive water loss- sweat, vomit, diarrhea
what is a hemorrhage and how does ADH respond
large amount of blood loss which results in a drop in BP
ADH responds by retain 99% of water in filtrate, kidney excretes little volume that is highly concentrated
what is the osmolarity when ADH is released compared to not being released
when released as high as 1200
when not released as low as 65
what is aldosterone
hormone secreted by adrenal cortex in adrenals: works with RAA system
acts to place several ion channels inside the collecting ducts
What are 2 actions of aldosterone
acts on the sodium-hydrogen channel: increases reabsorption of Na+ through secretion of Hydrogen( sodium pumped out, H+ pumped in for secretion)
sodium potassium pump: sodium is pumped out and K+ is pumped in for secretion
what is the overall result of aldosterone
increase blood volume and BP when needed
can be triggered by high K+ or low Na+
what are diuretics
substances act on nephron to increase urinary output
most diuretic drugs decrease Na+ reabsorption, less H2O is absorbed
what are 2 examples of diuretics and their effects
caffeine: cause renal tubules to increase in diameter, increase amount of flow through tubules
alcohol: inhibit release of ADH
what are cardiovascular baroreceptors
exert control over nephron to regulate blood volume
found in aortic arch and carotid sinus arteries under control of vagus and glossopharyngeal nerves
mechanorecptor: detect stretch inside vessels
how do cardiovascular baroreceptors regulate blood volume
if blood volume and BP rise baroreceptor inhibit sympathetic nervous system signal kidneys which dilates the afferent arteriole that brings blood to the glomerulus.
causes increase in filtration rate, increases output of water and sodium, reduces blood volume to normalize pressure
what are the characteristics of normal urine
clear and a pale yellow
has a distinctive odor: but not pungent
ammonia at end of urination: because of bacterial break down of urea
what causes the color of urine
urochrome: pigment derived from breakdown of hemoglobin
What are abnormal characteristic of urine
cloudy: pus- could be UTI
foods, drugs, blood
fruity smell: diabetics
What is the normal pH and density of urine
pH: 4.5-8: diet high in citrus/veg- more basic, high in protein more acidic
density: 1.003-1.035`
what is the composition of urine
95% water, 5% solutes
urea is most abundant solute: 2%
other wastes: uric acid, creatine, ammonia
solutes: Na, phosphate, sulfate calcium, magnesium, chloride, bicarbonate ion
where is water found in the body
intracellular: inside cells: 60% of fluid in the body
extracellular: outside cells: 40%
what are the 2 sections of the extracellular fluid
plasma: fluid portion of blood contain 3L or 8% total
interstitial: fluid in microscopic space between cells contain 12L or 32% total
what does the acid-base pH balance refer to
balance of concentration of hydrogen in blood
what is the pH scale
ranges 0-14
0=acidic, 14= basic
what is the normal pH of arterial blood and what indicates alkalosis and acidosis
7.35-7.45
alkalosis is arterial blood above 7.45
acidosis is arterial blood below 7.35
What controls the blood acidity
chemical buffers, brain stem respiratory and renal system
What is included as part of chemical buffers
anion: negative charged ion: HCO3-
cation: positive charged ion: ammonium NH4+
combinations of weak acid and its cation or weak base and its anion
Which 3 systems are chemical buffers
bicarbonate: acts as buffer of interstitial and plasma fluids
phosphate: buffers in urine and intracellular fluid
protein: main buffer intracellular fluid
what are the compositions of the bicarbonate, phosphate and protein systems as chemical buffers
bicarbonate: weak carbonic acid and bicarbonate
phosphate: weak acid (H2PO4) and mono hydrogen phosphate
protien: includes amino acids, hemoblogin, plasma proteins: 3x buffer capacity of all other systems
the respiratory center is responsible for
removing CO2 from blood
adding O2 to blood
what monitors the levels of CO2 in the blood
chemoreceptors in the medulla of the brain stem
what is reaction 1
CO2+H2O->H2CO3->H+ +HCO3-
what is formed when carbonic acid dissasociates in water
H+ and HCO3-
what is hyperventilation
increase in respiratory rate decreasing the amount of CO2 in the blood
what is hypoventilation
when respiratory system is depressed, blood pH is more alkaline, allows CO2 to accumulate
how is hyperventilation and hypoventilation resolved
hyperventilation: reaction 1 is pushed to the Left as CO2 is removed- using up H+ which causes pH to rise and balance restored
hypoventilation: reaction 1 is push to the R: forms more H+ ion, pH falls- more acidic and balance restored
define respiratory acidosis and respiratory alkalosis
respiratory acidosis: imbalance of pH due to CO2 retention
respiratory alkalosis: imbalance of pH due to CO2 removal
which major system is used to manage acid-base imbalances caused by daily metabolic processes
renal control system
functions: excrete or reabsorb bicarbonate
what is the acid base balance dependent on
secretion of H+ ion and conversion of bicarbonate
How is respiratory acidosis characterized
lower pH because of higher PCO2
caused by shallow breathing/limited gas exchange
causes renal system to fix by renal compensation
How is respiratory alkalosis characterized
higher pH because of lower PCO2
almost always caused by hyperventilation
causes renal system to fix by renal compensation
How is metabolic acidosis characterized
low pH, normal CO2, low bicarbonate
caused by buildup of acidic materials: acetic acid( alcohol), lactic acid, diabetic ketosis, extreme diarrhea
correction through respiratory compensation
How is metabolic alkalosis characterized
high pH, normal CO2, high bicarbonate
causes: vomit, intake excess antacids, constipation
correction through respiratory compensation
what are the normal blood serum levels
pH
PCO2
HCO3-
7.35-7.45 pH
35-45 mm
22-26 mEq/L
what is the process for determining if a patient is in acids or alkalosis and what is commentating if anything
- determine if patient is in acidosis or alkalosis
- determine if problem from respiratory or metabolic
- determine if condition is compensated
- if condition is compensated: what action is body taking
state values seen for respiratory acidosis: table 4.1
pH<7.35
PCO2>45 if causing condition
HCO3- > 26 if being compensated
body compensate: increased kidney retention of HCO3-
state values seen for respiratory alkalosis: table 4.1
pH>7.45
PCO2<35 if causing condition
HCO3-<22 if being compensated
body compensated: decreased kidney retention of HCO3-
state values seen for metabolic acidosis: table 4. 1
pH <7.35
PCO2<35 if being compensated
HCO3-<22 if causing condition
body compensated: hyperventilation to increase CO2 elimination
state values seen for metabolic alkalosis: table 4. 1
pH> 7.45
PCO2>45 if being compensated
HCO3>26 if causing condition
body compensated: hypoventilation to decrease CO2 elimination
