Chapter 24: Urinary System Flashcards
the kidneys receive __% of cardiac output
25
what are the major excretory organs of the urinary system
true
what organ produces urine?
kidneys
___ receive urine form the kidneys and move it to the bladder
ureters
ureters move urine to the bladder using 2 methods
gravity and peristalsis
___ receives and stores urine
bladder
what drives urination?
contraction in walls of the bladder
___ moves urine from the bladder to the outside
urethra
colour of the kidneys
reddish brown
what is the hilum?
medial indentation on the kidney, point of entry/exit for the renal artery, veins, nerves, and ureter
the kidneys empty into what part of the bladder?
posterior inferior
the kidneys are protected by __
visceral organs (anteriorly)
which kidney is slightly higher than the other?
left
what is the purpose of the fibrous capsule?
covers the outer surface of the kidney
what is the structure of the fibrous capsule?
projects collagen fibers through the perinephric fat to the renal fascia (support kidneys)
what is phrenic fat and its purpose?
thick layer of adipose tissue; support kidneys
what is the renal fascia and its function?
dense fibrous connective tissue that anchors the kidneys to surrounding structures
the fibrous capsule lines the __
real sinus (internal cavity in the kidney)
what is the renal cortex?
superficial region of the kidney
what is the renal medulla?
inner region of the kidney
the renal medulla is made of what two structures?
renal pyramid and renal column
what is the renal papilla?
the tip of the renal pyramid
what is the kidney lobe?
pyramid, the overlaying cortex and adjacent columns
each kidney contains __ to __ lobes
6-18
what is a minor calyx of the kidney? Function
collects urine from a single lobe
what a major calyx of the kidney? function
fusion of 4-5 minor calyces
what is the renal pelvis and function?
funnel-shaped structure that collects urine from major calyces
the renal pelvis is continuous with the __
ureter
what are nephrons?
microscopic functional units of the kidneys
what are the 2 types of nephrons?
- cortical nephrons
2. juxtamedullary nephrons
what type of nephrons represents 85% of all nephrons?
cortical
location of cortical nephrons
mainly in the cortex of the kidney
cortical nephrons are responsible for
most regulatory functions
structure of the juxtamedullary nephrons
long nephron loop that runs deep into the medulla
the juxtmedullary nephrons are essential to producing __
concentrated urine
what are the 2 components of a nephron?
- renal corpuscle
2. renal tubule
what is the function of the renal corpuscle?
makes filtrate by blood pressure forcing water and solutes out of the glomerular capillaries
what is filtrate?
protein-free solution like blood and plasma
filtrate is collected in the ___
capsular space
what is the renal tubule? Function?
tubular passageway up to 50mm long; recibevs filtrate and modifies it to make urine
the renal corpuscle is also called the __ or __
glomerular or Bowmans capsule
structure of the renal corpuscle
cup-shaped chamber
the renal corpuscle has a network of ___ known as __
capillary; glomerulus
function of the proximal convoluted tubule (PCT)
reabsorbs nutrients from the filtrate
once the filtrate enters the PCT it is called
tubular fluid
function of the nephron loop
establishes osmotic gradient for water reabsorption
each limb of a nephron loop contains 2 segaments
thick and thin
function of the distal convoluted tubule (DCT)
adjusts tubular fluid composition by reabsorption and secretion
what is the collecting system
series of tubes carrying tubular fluid away from the nephron
function of the collecting duct
collects fluid from nephron and carriers it through the renal medulla
the collecting duct is lined with 2 types of cells
- intercalated cells
2. principal cells
what is the role of intercalated cells in the collecting ducts?
secreting and reabsorbing hydrogen and bicarbonate ions
what is the function of principal cells in the collating ducts ?
reabsorb water and secret potassium
what is the function of the papillary duct?
collects fluid from multiple collecting ducts and delivers to minor calyx
function of the renal artery
delivers blood to the kidney
the renal artery branches into ___ in the renal sinus
segmental arteries
segmental arteries branch into __
interlope arteries
interlobal arteries branch into __
arcuate arteries
arcuate arteries branch into __
cortical radiate arteries
cortical radiate arteries branch into
afferent arterioles
afferent arterioles supply each nephron at a ___ known as a __
capillary knot; glomerulus
cortical radiate veins collect from ___ and drain into __
nephron capillary; arcuate veins
arcuate veins drain into
interlobar veins
interloper veins drain into the __
renal vein
the renal drains into the __
inferior vena cava
the afferent arteriole supplies blood to each individual __
nephron
the efferent arteriole carries blood from the __ to the __
glomerulus; pertibula capillaries
pertibulr capillaries surround the entire __ and are themselves surrounded by __
renal tube; peritubular fluid
functions of the peritubular capillaries
- collect water and solutes absorbed by the nephron
2. deliver other solutes to the nephron for secretion
peritubular capillaries drain into
radiate veins
blood flow around a juxtamentary nephron is the same until after it reaches the ___
peritubular capillaries
structure of the vasa recta
long straight capillaries connected to the distal end of the peritubular capillaries that parallel the nephron loop
function of the vasa recta
transport water and solutes in the renal medulla
the vasa recta drains into the __
cortical radiate veins
each kidney has ~ __ nephrons
1.25 million
both cortical and juxtamentary nephrons are innervated by
renal nerves
renal nerves enter at the __ and follow the branches of __
hilum; renal artery
most of the nerves in a nephron are ___ fibres from the __ and __ nerves
sympathetic postganglionic; cleiac plexus and inferior splenic nerves
sympathetic stimuli adjust blood flow and blood pressure at the __
glomeruli
sympathetic stimuli stimulate the release of __
renin
the urinary system maintains homeostasis by regulating the volume and composition of __
blood
3 examples of metabolic wastes
- urea
- creatinine
- uric acid
what is the most abundant organic waste?
urea
urea is a by-product of
amino acid break down
creatinine is a by product of
creatine phosphate breakdown in muscle
uric acid is formed during recycling of __
nitrogenous bases of RNA
what are the 3 processes in urine formation?
- filtration
- reabsorption
- secretion
describe process of filtration in urine formation
blood pressure forces water and solutes across the membranes of glomeruli capillaries into the capsular space
describe process of reabsorption in urine formation
transport of water and solutes from the tubular fluid across tubular epithelium into the peritubular fluid
describe process of secretion in urine formation
transport of solutes from the peritubular fluid across tubular epithelium into the tubular fluid
filtration occurs in the
renal corpuscle
regulation of final volume and solute concentration is from interaction between the __ and __
collecting system and nephron loops
filtration occurs at what part of the renal corpuscle
glomerulus
which has a smaller diameter: efferent or afferent arteriole?
efferent
T/F the smaller diameter of the efferent arteriole increases blood pressure in the glomerulus and increases filtration
treu
capsular space is found between layers of the __
glomerular capsule
function of the juxtaglomerular complex
secretes renin when glomeruli blood pressure decreases
what are intraglomerular mesangial cells? Location? Function?
supporting cells ; between adjacent glomerular capillaries; control capillary diameter and rate of blood flow
___ forms the outer wall of the renal corpuscle and covers the glomerular capillaries
glomerular capsule
the __ layer forms the outer capsule
parietal
the visceral layer the glomerular capsule covers the
capillaries
the visceral layer of the glomerular capsule is made of
podocytes
structure of podocytes
large cells with foot processes that wrap around glomerular capillaries
gaps between adjacent pedicels are called
filtration slits
what are the 3 layers of the filtration membrane?
- fenestered glomerular capillaries
- dense basement membrane
- filtration slits from podocytes
fenestered glomerular capillaries contain large __
pores
the 3 filtration membranes keeps ___ from entering the capsular space
most plasma proteins
what 5 factors affect glomerular filtration?
- glomerular hydrostatic pressure
- capsular colloid osmotic pressure
- blood colloid osmotic pressure
- capsular hydrostatic pressure
- net filtration power
what is glomerular hydrostatic pressure and where does it push water and solutes?
blood pressure in glomerular capillaries; from plasma to filtrate
what is blood colloid osmotic pressure and where does it move water?
pressure due to materials in solution; from filtrate to plasma s
capsular hydrostatic pressure tends to move water and solutes __
from filtrate to plasma (opposes filtration )
capsular hydrostatic pressure results from resistance of
filtrate already in the nephron
what is net filtration pressure?
pressure acting across the glomerular capillaries
net filtration pressure represents the same of __
hydrostatic and colloid osmotic pressures
what 2 interacting levels of control help stabilize glomerular filtration rate?
- autoregulagtion at local level
2. central regulation (endocrine and sympathetic)
the juxtaglomerular complex plays a key role in responding to decreased GFR by initiating ___
renin-angiotensin-aldosterone system (RAAS)
__ predominates in the proximal convoluted tubule
reabsorption
t/f only about 15-20% of initial fluid reaches the DCT
true, because mostly absorbed by PCT
a combination of __ and ___ in the DCY alters solute composition in the tubular fluid
reabsorption; secretion
sodium ions are excreted in exchange for __
potassium
hydrogen ions are secreted in exchange for __
sodium
carrier proteins can secrete __ and __
toxins; drugs
