URINARY SYSTEM Flashcards
- receive 25 percent of the cardiac output
- major excretory organs of the urinary system
- produces urine
Kidneys
- receive urine from the kidneys
- conduct urine to the urinary bladder by gravity and peristalsis
ureters
- receives and stores urine
- contraction of muscle in walls drives urination
urinary bladder
- conducts urine from the bladder to outside the body
urethra
- adjusting blood volume and blood pressure
- regulation of blood plasma concentrations of sodium, potassium, chloride, and other ions
- stabilizing blood pH
- conserving valuable nutrients by preventing their loss in urine
- removing drugs and toxins from the bloodstream
Functions of the urinary system
- paired
- reddish, bean-shaped
Kidneys
- Kidney is a retroperitoneal organ because its location is ______________
posterior to the peritoneum of the abdominal cavity
Kidneys are located between the levels of the last _________ vertebrae and ____________ vertebrae, partially protected by the ______ and _______ ribs
- thoracic
- 3rd lumbar
- 11th
- 12th
- ________ kidney is lightly lower than the ________ because of the liver occupying the space on the right side above the kidney
right, left
Length of kidney?
10 - 12 cm
width of kidney
5 - 7 cm
thickness of kidney?
3cm
Weight of kidney?
135 - 150 grams
Indentation at the center of a kidney is called what?
renal hilum
Part of kidney where the ureter, blood vessels, nerves, and lymphatics emerge
Renal hilum
3 coverings of the kidney
- renal capsule (fibrous capsule)
- adipose capsule (perinephric fat)
- renal fascia (gerota’s fascia)
- covers the outer surface of the kidney
- projects collagen fibers through the perinephric fat to the renal fascia
Renal capsule (fibrous capsule)
- Covering of the kidney consisting of thick layer of adipose tissue
adipose capsule (perinephric fat)
- covering of the kidney that anchors kidney to the surrounding structures
renal fascia (Gerota’s fascia)
- innermost layer
- smooth, transparent sheet of dense irregular connective tissue continuous with the other coat of the ureter
- serves as a barrier for trauma
- helps maintain the shape of the kidney
Renal capsule
- middle layer
- mass of fatty tissue surrounding the renal capsule
- also protects the kidney from trauma and holds it firmly in place within the abdominal cavity
Adipose capsule (perinephric fat)
- outer most layer
- thin layer of dense irregular connective tissue
- anchors kidney to the surrounding structures and to the abdominal wall
Renal fascia (Gerota’s fascia)
2 regions of the kidney?
- renal cortex
- renal medulla
- superficial light red region
- smooth texture
- extends from renal capsule, the bases of renal pyramids and into the bases between them
renal cortex
- periods of cortex that extend between the renal pyramids
renal columns of Bertini
- deep, darker reddish brown inner region
- consists of several renal pyramids
renal medulla
- cone shaped
- base (wider end) faces the cortex
- apex (narrower end) points towards the renal hilum
renal pyramid
apex of renal pyramid is also known as?
renal papilla
- these constitute the parenchyma of the kidney
- contains millions of nephrons
Renal cortex and renal pyramids of the renal medulla
functional unit of the kidney
nephron
middle indentation in the kidney
renal hilum
collects urine from a single kidney lobe
minor calyx
forms from the fusion of 4-5 minor calyces
major calyx
- funnel-shaped structure that collects urine from major calyces
- continuous with the ureter
renal pelvis
filtrate formed by the nephrons drain into the large ___________ which extend through the renal papillae of the pyramids
papillary ducts
papillary ducts drain into the __________________
minor and major calyces
pathway of filtrate/urine?
- collecting ducts
- papillary ducts
- minor calyces
- major calyces
- renal pelvis
- ureters
- urinary bladder
once the filtrate enters the calyces it becomes urine because ___________________
no further reabsorption can occur
2 components of nephron
- renal corpuscle
- renal tubule
in this component:
* blood pressure forces water and solutes out of the glomerular capillaries in process called filtration
* produces filtrate that is collected in the surrounding capsular space
renal corpuscle
in this component:
- tubular passageway up to 50 mm long
- receives filtrate and modifies it to create urine
renal tubule
4 segments of a nephron?
- renal corpuscle
- proximal convoluted tubule
- nephron loop
- distal convoluted tubule
- contains glomerular capsule
- glomerulus
renal corpuscle
- reabsorbs nutrients from filtrate (now called tubular fluid)
proximal convoluted tubule
- establishes osmotic gradient for water reabsorption
- each limb contains a thin segment and a thick segment
nephron loop
- adjusts tubular fluid composition by reabsorption and secretion
distal convoluted tubule
series of tubes carrying tubular fluid away from nephron
collecting system
- collects fluid from many nephron
- carries fluid through the renal medulla
COLLECTING DUCT
the collecting duct is lined with two main type of cells which are?
- intercalated cells
- principal cells
CELL IN COLLECTING DUCT that play a role in secreting and reabsorbing hydrogen and bicarbonate ions
intercalated cells
CELL IN COLLECTING DUCT THAT reabsorb water and secrete potassium
principal cells
- collects fluid from multiple collecting ducts
- delivers fluid to minor calyx
papillary duct
2 types of nephron
- cortical nephron
- juxtamedullary nephrons
- 85% of all nephron
- located primarily in the cortex
- responsible for most regulatory functions
cortical nephrons
- 15% of all nephrons
- long nephron loop extending deep into medulla
- essential to producing concentrated urine
juxtamedullary nephrons
- delivers blood into kidney and branches into segmental arteries
renal artery
- segmental arteries branch into __________ in the renal sinus
interlobar arteries
- Segmental arteries branch into __________ which arch long the boundary between renal cortex and renal medulla
arcuate arteries
Arcuate arteries branch into?
cortical radiate arteries/interlobular arteries
cortical radiate arteries branch into _______________ which supply each nephron, specifically a capillary known as glomerulus
afferent arterioles
- surround the entire renal tubule
- surrounded by peritubular fluid
- collect water and solutes absorbed by the nephron
- deliver other solutes to the nephron for secretion
- drain into cortical radiate veins
peritubular capillaries
- connected to the distal end of the peritubular capillaries
- long, straight capillaries that parallel the nephron loop
- transport water and solutes within the renal medulla
- drain into cortical radiate veins
vasa recta
- collects blood from the capillaries of the nephron and drain into arcuate veins
cortical radiate veins
Arcuate veins -> interlobar veins -> renal veins -> ____________________
inferior vena cava
3 processes in urine formation
- filtration, absorption, and secretion
filtration occurs only in the __________
renal corpuscle
- balance between reabsorption and secretion varies in remaining _____________segments
nephron
regulation of final volume and solute concentration is from the ________ between the collecting system and the nephron loops
interaction
- transports, stores, and eliminates urine
- includes the ureters, urinary bladder, and urethra
- can be visualized using a pyelogram
urinary tract
- paired muscular tubes extending from the kidney to the urinary bladder (30 cm)
- retroperitoneal and attached to the posterior abdominal wall
ureters
- hollow, muscular organ holding up to a liter of urine
urinary bladder
3 anatomic segments of ureter?
- abdominal ureter
- pelvis ureter
- intramural ureter
abdominal ureter extends where?
renal pelvis to iliac vessels
pelvic ureter extends where?
iliac vessels up to bladder
intramural ureter extends where?
within the bladder
Radiologic segments of the ureter
- proximal ureter
- middle ureter
- distal ureter
where is the proximal ureter?
above the sacroiliac (SI) joint
where is the middle ureter?
over the SI joint
where is the distal ureter?
below the SI joint and its entrance to the bladder
3 ureteric constrictions?
- at the ureteropelvic junction (UVJ)
- at the crossing of the external/common iliac artery
- at the side of entrance of bladder (ureterovesical junction)
Narrowest part of the ureter?
the ureterovesical junction
Blood supply of: proximal ureter and where is it located
renal artery, located medially
Blood supply of: middle ureter, and where is it located?
abdominal aorta/common iliac artery, located posteriorly
Blood supply of: distal ureter, and where is it located?
superior vesical artery (branch of internal iliac artery), located laterally
3 layers of ureters
- inner mucosa
- middle muscular layer
- outer connective tissue layer
transitional epithelium and surrounding lamina propria
inner mucosa
bands of smooth muscle that create peristaltic waves to move urine to the bladder
middle muscular layer
continuous with the fibrous capsule and peritoneum
outer connective tissue layer
- filled by the ureters and drained by the urethra
- dimensions vary with the state of distension
- posterior, inferior, and anterior surfaces outside the peritoneal cavity
- anchored to the pelvic and pubic bones by supporting ligaments (lateral and middle umbilical ligaments)
urinary bladder
folds in the bladder lining that disappear with expansion as the bladder fills
rugae
slitlike shape helps prevent backflow of urine into ureters with bladder contraction
ureteric orifices
penetrate posterior bladder wall at an oblique angle
ureters
- triangular area bounded by the ureteral opening and the entrance to the urethra
- most vascular portion of urinary bladder
trigone
- surrounds the urethral opening
- contains a muscular internal urethral sphincter (involuntary smooth muscle)
neck of the urinary bladder
- superior vesical artery
- inferior vesical artery (males)
- vaginal arteries
- obturator artery
- inferior gluteal artery
blood supply of the urinary bladder
contains mucosa, submucosa. and muscularis layers
wall of the urinary bladder
3 layers of the muscularis layer of the wall of urinary bladder
- inner longitudinal layer
- circular layer
- outer longitudinal layer
the 3 layers of the muscularis layer forms the __________
detrusor muscle
- extends from the neck of the urinary bladder to the exterior of the body
- different length and function in males vs females
urethra
the _ (gender) urethra is longer and transports semen as well as urine
Male
- lined with stratified epithelium that varies by location
- transitional at the _____
- stratified columnar at _____
- stratified squamous near the _______
- wall of urethra
- neck
- midpoint
- external urethral orifice