Urinary Physiology Flashcards
The interlobar arteries divide into the
arcuate arteries
Which of the following lists contains the correct order of fluid flow through the urinary system?
PCT, loop of Henle, DCT, collecting duct, calyces, renal pelvis, ureters
Females are more susceptible to UTIs because they have
a shorter urethra than men.
From the collecting ducts of the nephrons, urine drains directly into the
minor calyces.
The terminal portion of the urinary system is the
urethra
The functional unit of the kidney is a (n)
nephron
A physician that specializes in the branch of medicine focusing on problems of the male and female urinary system and the male reproductive system is called a(n)
urologist.
The small blood vessel carrying blood out of the glomerulus is the
efferent arteriole
The tube that carries urine from the urinary bladder out of the body is called the
urethra
The renal pyramids are located in the
renal medulla
The double-walled epithelial cup that surrounds the glomerular capillaries and collects the filtrate is called the
bowmans’ capsule
Most glucose molecules are reabsorbed in the
proximal convoluted tubule
The first portion of the renal tubule is the
PCT
Which of the following represents the correct order of anatomical structures found in the nephron?
glomerulus, proximal convoluted tubules, loop of Henle, distal convoluted tubules
Factors that aid venous return include ALL BUT:
greater urinary output
maintain the volume and composition of body fluids within normal limits
urinary system
rid the body of waste products that accumulate as a result of cellular metabolism
urinary system
sometimes referred to as excretory system
urinary system
maintains an appropriate fluid volume by regulating the amount of water that is excreted in the urine
urinary system
regulating the concentrations of various electrolytes in the body fluids and maintaining normal pH of the blood.
urinary system
excrete some waste products, such as carbon dioxide and water
lungs
rids the body of wastes through the sweat glands
skin
excrete bile pigments that result from the destruction of hemoglobin.
liver and intestines
In addition to maintaining fluid homeostasis in the body, the urinary system controls red blood cell production by secreting what hormone
erythropoietin
enzyme that urinary system secrete that plays a role in maintaining normal blood pressure
renin
consist of the kidneys, ureters, urinary bladder, and urethra.
urinary system
create the urine and account for the other functions attributed to the urinary system.
kidneys
organs that filter the blood, remove the wastes, and excrete the wastes in the urine.
kidneys
organs that perform the functions of the urinary system
kidneys
approximately 3 cm thick, 6 cm wide, and 12 cm long. It is roughly bean-shaped with an indentation
kidneys
located between the twelfth thoracic and third lumbar vertebrae, one on each side of the vertebral column.
kidneys
usually is slightly lower than its counterpart because the liver displaces it downward.
right kidney
protected by the lower ribs, lie in shallow depressions against the posterior abdominal wall and behind the parietal peritoneum.
kidney
Is in retroperotineal positio
kidneys
connective tissue that holds the kidney in place
renal fascia
adipose tissue surrounds the kidney
perineal fat
tough, fibrous, connective tissue that closely envelopes each
kidney and provides support for the soft tissue that is inside
renal capsule
indentation of the kidney on the medial side, leads to the renal sinus
hilum
Where the ureter and renal vein leave the kidney
hilum
Renal artery enters the kidney through this
hilum
carry the urine away from kidneys to the urinary bladder
ureter
temporary reservoir for the urine
urinary bladder
tubular structure that carries the urine from the urinary bladder to the outside.
urethra
outer, reddish region, next to the capsule
renal cortex
darker reddish-brown region
renal medulla
appear striated because they contain straight tubular structures and blood vessels
renal pyramids
wide bases of the pyramids are adjacent to the cortex and the pointed ends
renal papillae
Portions of the renal cortex extend into the spaces between adjacent pyramids to form
renal column
The cortex and medulla make up the what of the kidney
parenchyma
located in the renal sinus, and is continuous with the ureter
renal pelvis
large cavity that collects the urine as it is produced.
renal pelvis
part of the renal pelvis that is interrupted by cuplike projections (calyces
periphery
surrounds the renal papillae of each pyramid and collects urine from that pyramid
minor calyx
Several minor calyces converge to form a
major calyx
functional units of the kidney
nephrons
composed of renal corpuscle and renal tubule
neprons
consists of a cluster of capillaries, called the glomerulus, surrounded by a double-layered epithelial cup, called the glomerular capsule
renal corpuscle
leads into the renal corpuscle
afferent arteriole
leaves the renal corpuscle.
efferent arteriole
which monitors blood pressure and secretes renin, is formed from modified cells in the afferent arteriole and the ascending limb of the nephron loop.
juxtaglomerular apparatus
small tube, about 25 cm long, that carries urine from the renal pelvis to the urinary bladder
ureters
It descends from the renal pelvis, along the posterior abdominal wall, which is behind the parietal peritoneum, and enters the urinary bladder on the posterior inferior surface
ureter
three layers of ureter
fibrous coat
muscular coat
mucosa
supporting layer of fibrous connective tissue.
fibrous coat
consists of the inner circular and outer longitudinal smooth muscle
muscular coat
Main function is peristalsis to propel the urine
muscular coat
transitional epithelium that is continuous with the lining of the renal pelvis and the urinary bladder
mucosa
secretes mucus, which coats and protects the surface of the cells.
mucosa
temporary storage reservoir for urine. It is located in the pelvic cavity, posterior to the symphysis pubis, and below the
parietal peritoneum.
urinary bladder
Size and shape varies with the amount of urine it contains and with the pressure it receives from surrounding organs
urinary bladder
lining is a mucous membrane of what kind of epithelium that is continuous with the ureters
transitional epithelium
numerous folds of the mucosa when the bladder is empty
rugae
allow the bladder to expand as it fills
rugae and transitional epithelium
second layer of urinary bladder that supports the mucous membrane
submucosa
composed of connective tissue with elastic fibers
submucosa
layer of the urinary bladder composed of smooth muscle
muscularis
interwoven in all directions and, collectively, these are called wherein its contraction expels urine from the bladder
detrusor muscle
outer layer of the bladder on the superior surface
parietal peritoneum
outer layer of the bladder except the superior surface
fibrous connective tissue
triangular area formed by three openings in the floor of the urinary bladder.
trigone
Two of the openings are from the ureters and form the base of the trigone
trigone
small flaps of this cover the openings of the trigone and act as valves that allow urine to enter the bladder but prevent it from backing up from the bladder into the ureters
mucosa
where the third opening is located, opening into the urethra
apex
band of detrusor muscle encircles the opening to form the
internal urethral sphincter
a thin-walled tube that conveys urine from the floor of the urinary bladder to the outside.
urethra
Its wall also contains smooth muscle fibers and is supported by connective tissue.
urethra
urethra is short, only 3 to 4 cm (about 1.5 inches) long
what sex
female
urethra is much longer, about 20 cm (7 to 8 inches) in length, and transports both urine and semen
what sex
male
opening of urethra to the outside
external urethral orifice
skeletal (voluntary) muscle and encircles the urethra where it goes through the pelvic floor
external urethral sphincter
mucosal lining of the urethra is made out of this
transitional epithelium
surrounds the beginning of the urethra, where it leaves the urinary bladder.
internal urethral sphincter
smooth (involuntary) muscle.
internal urethral sphincter
The external urethral orifice opens to the outside just anterior to the opening for the
vagina
the first part, next to the urinary bladder, passes through the prostate gland and is called the
prostatic urethra
The second part, a short region that penetrates the pelvic floor and enters the penis, is called the
membranous urethra
third and longest region, This portion of the urethra extends the entire length of the penis, and the external urethral orifice opens to the outside at the tip of the penis.
spongy urethra
consist of two kidneys and two ureters, a urinary bladder and urethra
urinary system
urinary system function
Regulation of plasma ion composition
▪
Regulation of blood pH (with lung)
▪
Production of hormones
▪
Excretion of waste
blood becomes this when CO2 in the body decreases
acidic
highly distensible due to the presence of transitional epithelium
urinary bladder
carry filtered blood after it flows through the kidney through the renal artery
renal vein
divided into cortex (outer portion), medulla (inner portion
kidney
contain renal pyramids and renal columns (latin word for middle)
medulla
where urine goes into, edges are made of major and minor calyces
renal pelvis
have 20-25% resting cardiac output goes through kidneys
renal blood supply
blood not engaged in direct circulation
resting cardiac output
nephrons grouped at pyramids
capillaris units
study the pathway for urinary system
L&R renal arteries (segmental > arcuate > interlobular) > afferent arterioles > glomerulus (capillary network) > efferent arterioles > peritubular capillaries > interlobular veins > arcuate veins > interlobar vein > renal vein
unit of renal function: corpuscle and tubule
nephrons
study path of blood flow
page 5
forms filtrate
corpuscle
study filtrate pathway
Glomerulus and glomerular capsule (cortex) -> proximal convoluted tubule (cortex) -> descending loop of henle (into medulla) -> ascending loop of henle (into medulla)
-> distal convoluted tubule (cortex) -> collecting duct -> minor calyx
preliminary state of urine
filtrate
also known as bowman’s capsule
glomerular capsucle
called this because it runs along the corticomedullary junction
arcuate artery
3 basic operation
glomerular filtration
tubular reabsorption
tubular secretion
filter plasma
glomerular filtration
reabsorb needed compounds & water from filtrate
tubular reabsorption
secrete some materials into filtrate
tubular secretion
products of secretion in the urine
ammonia and urea
two layers of capsule surround glomerulus, between is capsular space
glomerular filtration
support capillary epithelium
podocytes
also called albuminuria, is elevated protein in the urine. It is not a disease in and of itself but a symptom of certain conditions affecting the kidneys.
proteinuria
blood pressure for filtration
filtration pressure
opposes filtration pressure
colloid osmotic pressure and capsular pressure
diameters adjust to maintain a net filtration pressure
efferent and afferent arteriole
change in width with small changes in blood pressure
efferent and afferent arterioles
conventional kidney function test
glomerular filtration rate
➢105-125 ml/min (normal values)
➢Measured by injection of radioisotope to be detected by a conventional x-ray
➢Determines net reabsorption because it determine filtrate flow
➢ANP increases GFR
➢Vasoconstriction decreases GFR
glomerular filtration rate
exerts a vasodilator effect on the kidney and also reduces tubular reabsorption of sodium
atrial natriuretic peptide
in this there is a bout ~65% Na+ + H2O, normally 100% nutrients and about ~100% HCO3- depending on blood pH
proximal tubule
➢There is an active transport of soutes
➢Osmosis moves water
➢Cells distal to proximal tubule fine tune reabsorption under control
proximal tubule
takes place all along tubule, major substances include H+, K+, ammonia, urea, creatine, drugs like penicillin
tubular secretion
➢Helps regulate plasma pH 7.35-7.45
➢If diet is acid, urine is typically acidic
tubular secretion
collecting duct to calyces > ureter > bladder > urethra
urine route
stimulates NaCl in proximal tubule
angiotensin II
increases Na+ reabsorption and K+ secretion in DCT and CD
aldosterone
the more of this absorbed, the more water
Ion
increases GFR and inhibits aldosterone action -> less NA+ reabsorbed
ANP
responds to increased concentration of solute in blood + fall in blood pressure
antidiuretic hormone
➢
Important to body water balance
➢Increased concentration of solute in blood + fall in bp causes this to increase
➢Without this, DCT and CD walls are impermeable to water causing a dilution to urine
➢With this, water reabsorption occurs, causing a concentrated urine
antidiuretic hormone
about 1-2L per day are created
urine
95% water, urea, K+, ammonia, uric acid, Na+, Cl-, Mg2+, sulfate, phosphate, and Ca2+
urine
study pathway page 7
+1
lined with mucus, transitional epithelium, pass under bladder and a full bladder prevents backflow
ureter
directly infront the rectum, can stretch (700-800ml), smaller in females because of uterus, three layers of detrusor muscle
bladder
internal urethral sphincter
urethra
term for urination
micturition
autonomic reflex, responds to stretch like rectum
internal sphincter
detrusor muscle contraction is what
parasympathetic/sympathetic
parasympathetic
conscious control what kind of sphincter
external sphincter
during this, kidneys shrink, decreasing in capacity
➢Thirst increases leading to dehydration
➢Lead to more UTIs
➢Both suffer from nocturia
aging
lead to prostate enlargement, frequent urination and slow flow
male aging
more prone to leakage of external sphincter (incontinence)
female aging
the need for patients to get up at night on a regular basis to urinate
nocturia
E.g.sodium, potassium,
calcium, and magnesium
plasma ion coomposition
hormone produced in urinary system
erythropoietin
- counts the RBCs that passes through the organ, prompted to produce
erythropoietin to make the bone marrow to produce new RBCs to compensate
for the low RBC count
kidney
to increase CO2, ____ acid is broken down (excess carbon dioxide in blood plasma)
carbonic
makes the blood acidic in nature
carbonic aicd
part is situated in the cortex,
part is situated in the medulla
nephrons
haped like a funnel, where
all the collecting tubules of urine converges, urine travels
through the apex of the renal pyrami
renal pyramids
passageway for blood vessels
to penetrate the kidney
renal column
where the renal artery goes to
starting point where blood filtration begin
renal cortex
: where renal artery,
renal vein, and renal tubule
pass through
renal hilum
kidney > dissecting dish > ___ plane
sagittal
kidney > inside the body > ____ plane
coronal
concave
side is the location of
renal hilum
pertains to the blood that left the heart that is not actively engaged in gaseous exchange
cardiac output
venous side of renal blood supply starts where
peritubular capillaries
blood vessles that run across the tubules
peritubular capillaries
last artery if there is no glomerulus
renal arteries
small arteries that branch off renal arteries (4)
segmental
interlobar
arcuate
interlobular
point of entry for glomerulus
afferent arterioles
refers to the direction wherein the group of vessels that arcs into the renal pyramid
arc
where filtration begins (outside going into the cortex)
renal arteries
where filtered blood is produced
corpuscle
collection of peritubular capillaries
glomerulus
glomerulus and PCT are part of what
cortex
Loop of henle is part of what
medulla
DCT is part of what
cortex
reabsorption is needed because the ___ cannot distinguish
glomerulus
fine tuned (where nitrogenous waste are delivered)
tubular secretion
has sensory cells (J-G Cells)
ascending limb of loop of henle
detect whether the person is producing
adequate urine (causes AA to dilate to
enter)
jackstone glomerular cells
where “clean” blood
comes out
efferent arteriole
why is the afferent arteriole thicker?
> there is need to build up pressure inside the glomerulus
volume of blood is lower when it comes out the efferent
arteriole
people who undergo dialysis suffer from ____
hypotension
not directly attributed to excess consumption of salt (more associated with hypertension)
kidney stones
where actual blood filtration takes place
glomerulus
- lining of the glomerulus is made out of this
simple squamous epithelium
can detect renal cyst (benign in
nature), enlargement of renal corpuscle (obstruction of nephrons)
CT scan
the squamous cell (squamous cell carcinoma), divided abnormally and very fast
RENAL CELL CARCINOMA
under normal conditions, urine can have 0-1 squamous cells (indication is normal) but detection of squamous cells (more than 1, too numerous to count) indicate physical injury of glomerulus
> may indicate urinary tract infection (UTI)
URINARLYSIS
excess amount of calcium and oxalates
kidney stones
much of the reabsorption takes place here
PCT
