11/1: Urinary System Flashcards
What are the functions of the urinary system?
Elimination of urine/toxicity
Conservation of salts, glucose, proteins, water
Regulation of blood pressure, blood hemodynamics, and acid-base balance
Endocrine organ, produces Vit D, renin, erythropoietin prostoglandins
What are the parts of the urinary system?
Kidneys (with ureter)
Urinary bladder
The kidneys and most of the ureters are…
Primarily retroperitoneal (not part of the gut tube and never had a mesentery)
The urinary bladder and lower ureters are…
Subperitoneal (sitting down in pelvis below peritoneum)
What are the kidneys surrounded by?
Perinpehric fat layer and a second paranephric fat layer over that
What is the best way to access the kidneys?
Posteriorly
What does the right kidney contact?
Ascending/transverse colon, liver and gallbladder, duodenum, and inferior vena cava
What does the left kidney contact?
Stomach, pancreas, descending colon, jejunum, and spleen
The kidney has no significant ________
Collateral arterial circulation
What is the exterior of the kidney covered by?
Renal capsule (divided into superior and inferior poles)
Where does the outer cortex extend into?
Medulla
What does the medulla form?
Renal columns
What does the inner medulla contain?
Renal pyramids
What is the function of renal pyramids?
urine is filtered and proessed
What do the renal pyramids curve down to form?
Minor calyx
Where is urine secreted into prior to minor calyx?
Renal papilla (base of renal pyramid)
What do several minor calyx come together to form?
Major calyx (2-3)
What do major calyx form?
Renal pelvis
What does the renal pelvis exit as and turn into?
Kidney at the hilum as the ureter
What is the renal sinus?
Spaces filled with fat
What is the relationship between the ureters and the gonadal vessels?
Ureters pass behind the gonadal vessels
“Water under the bridge”
Where do the ureters pass across?
The anterior surface of the psaos muscle and common iliac vessels
What is the right ureter at risk of?
Injury during appendectomy
What is the left ureter crossed by?
Sigmoid colon
What is the left ureter at risk of?
Injury of sigmoid colon and rectum during surgery
Where do the ureters get their blood supply?
Superiorly: renal a
Middle: gonadal a
Inferiorly: internal iliac a
What is a common clinical correlation with our kidneys?
Kidney stones
What are kidney stones formed from?
Extravasation of urine into surrounding soft tissue
What are the 3 places where kidney stones occur?
- pelvic brim
- ureter and pelvis
- detrusor and ureter
The smaller the stone, the _________ it will go before lodging
farther
What is the arterial blood supply of the kidney?
via renal artery
What does the renal artery branch into?
Anterior and posterior renal arteries which then divide into 5 segmental arteries after entering hilum
What do the 4 branches of anterior renal artery supply?
Apical
Superior
Middle
Inferior segments
What does 1 of the segments of the posterior renal artery supply?
Posterior segment
What do segmental arteries give off?
Many lobar arteries
What do lobar arteries supply?
Renal pyramid with branching interlobal arteries
What is the ureter covered by?
Parietal peritoneum
Where does the ureter enter the bladder?
At an oblique angle forming a flap valve
What occurs when bladder fills with urine?
The thickness of the detrusor muscle wall is compressed which pushes the ureter to be closed to prevent urine backflow
How does urine pass down the ureters?
By peristaltic contractions (12-20 sec intervals few drops enter urinary bladder)
What is the blood supply of the ureter?
Via area/vessels they contact
What is the ureters blood supply near the kidney?
Via renal artery
What is the ureters blood supply near the pelvis?
Via gonadal arteries
What is the ureters blood supply into the pelvis?
Via common iliac and internal iliac and its branches
What is the urinary bladder made of?
Detrusor muscle
What is the function of the detrusor muscle?
Store urine
What is a characteristic of the detrusor muscle?
Distensibility: Ability to fill and expand in contract
How is the urinary bladder separated from pubic bones via?
Retropubic space
What is the arterial blood supply of the urinary bladder?
branches of the internal iliac artery
What is the venosu drainage of the urinary bladder?
Internal iliac vein
What is the trigone?
Triangular area created by ureter opening and internal urethral orifice
What is the itnernal urethral orifice?
Opening into urethra
What does the internal urethral orifice contain?
Internal urethral sphincter which is involuntary
What happens to the internal urethral orifice in males?
Contracts during ejaculation to prevent retrograde ejaculation
Differences between male and female bladder anatomy
What does the kidney and ureter innervation arise from?
Renal nerve plexus and consists of sympathetics (splenchnic) and parasympathetics (Vagus) fibers
What do nerves of abdominal parts of ureter derive from?
Renal, abdominal aortic, and superior hypogastric plexuses
Describe the reffered pain of the ureter?
Visceral afferent fibers
follows sympathetic fibers backwards to spinal ganglia and cord segments T11-L2
Where is ureter referred pain felt?
In groin and ipsilateral lower quadrant of the anterior abdominal wall
In the urinary system what is the parasympathetic role?
Producing and releasing waste (urine and feces) from the body
In the urinary system what is the sympathetic role?
Slowing production of waste, while retaining it inside the body until proper time to release it
In the urinary system what is the somatic motor role?
Assisting sympathetics in retaining waste
In the kidney and renal vessels, what do the sympathetics function for?
Decrease urine production through vasoconstriction
In the kidney and renal vessels, what do the parasympathetics function for?
No obvious function
What do vagus fibers that reach the kidney carry?
Visceral afferent information
Describe peristalsis in the renal pelvis and upper ureter?
Largerly myogenic as a response to stretching when filled with urine
Describe peristalsis in the lower ureter?
Parasympathetics increase peristalsis
Sympathetics inhibit peristalsis
Describe parasympathetics at the bladder?
Parasympathetics (pelvic splenchnic nn. from S2-4) eliminate urine
What muscle contacts at the bladder due to parasympathetics?
Detrusor muscle (bladder wall)
What do parasympathetics at the bladder inhibit?
The internal (involuntary) urinary sphincter, causing it to relax and open
Describe where the sympathetics from the bladder come from?
Mostly from L1
Describe where somatic motor comes from at the bladder?
Pudendal n. from S2-4
What does somatic motor at the bladder retain?
Urine
What do sympathetics at the bladder cause?
The detrusor to relax
Internal sphincter to constrict and close (involuntary functions)
What kind of muscle is the external urinary sphincter?
Skeletal muscle, used voluntarily to prevent urination
What is the aoricorenal ganglion?
Plexus surrounding aorta and lead to kidneys
What are parasympathetics for ureters mostly from?
Pelvic splanchnic nn
Where are pelvic splanchnic nn most important?
Distally
Where are sympathetics of the urinary system from?
Lesser splanchnic nn, mostly from T11-L2
What is the urethra?
Final outflow tract from bladder to external urethral orrifice to exit
Describe the urethra in females?
Shorter and straight (most likely to get UTI’s because easier for pathogens to travel up shorter distance)
Describe the urethra in males?
Long, curves, through prostate and penis muscles
What are horseshoe kidneys?
lower poles fuse during “assent” and are relocated and sunken under inferior mesenteric artery
What are ectopic kidneys?
Out of norma position. Most common is pelvic kidney with hilum facing anteriorly
What are ectopic ureters?
Most common is bifid ureters (2, can join together or separate)
