The Urinary System Flashcards
What vertebral levels do the kidneys lie at?
T12-L3
Which kidney lies slightly lower and why?
The right one, due to the presence of the liver
What are the anterior relations of the right kidney?
Suprarenal Gland Liver Duodenum (2nd part) Right colic flexure Small intestine
What are the anterior relations of the left kidney?
Suprarenal Gland Spleen Stomach Pancreas Left colic flexure Descending colon Jejunum
What are the posterior relations of the left and right kidney?
Diaphragm
Psoas major, quadratus lumborum, transversus abdominus
Ribs (right 12th) (left 11-12th)
Sub costal, iliohypogastric and ilioinguinal nerves
What are the kidneys surrounded by (from internal to external)?
Renal capsule
Perirenal (periphrenic fat)
Renal fascia
Pararenal (paraphrenic fat)
What are the structures that enter at the hilum of the kidney (from front to back)?
Renal vein
Renal artery
Ureter
Describe the passage of drainage from the renal pyramid to the ureter?
Renal papilla
Minor calyx
Major calyx
Renal pelvis
What are renal columns?
They separate each renal pyramid
What is a renal lobe?
An area of the kidney consisting of a renal pyramid and its overlying renal cortex
What vertebral level do the renal arteries arise at?
Between L1 and L2
Which renal artery is longer and why?
Right renal artery, because the abdominal aorta lies slightly to the left of the midline
Which of the renal veins is longer?
The left renal vein, because the IVC lies slightly to the right of the midline
Does the right renal artery pass the IVC anteriorly or posteriorly?
Posteriorly
What are the 5 segmental branches of the renal artery?
Apical (superior) Anterosuperior Anteroinferor Inferior Posterior
Describe the pathway of arterial supply once it enters the kidney
Segmental arteries > Interlobar arteries > arcuate arteries > interlobular arteries > afferent arterioles >glomerulus > efferent arterioles > vasa reta/peritubular capillaries
What is the difference in the blood supply in the cortical nephron compared to that of the juxtamedullary nephron?
Cortical nephron - peritibular capillaries
Juxtamedullary nephron - vasa recta
What is the venous drainage of the kidney?
The vasa recta and peritubular capillaries both drain into:
- Interlobular vein
- arcuate vein
- Interlobar vein
- Renal veins
What is the lymphatic drainage of the kidneys?
They drain into the para-aortic lymph nodes (located around the renal artery)
What is the sympathetic innervation of the kidney?
What does it cause?
Least splanchnic nerve
Aorticorenal ganglion
Sympathetic stimulation leads to constriction of the vessels
How long are the ureters?
25cm
What are the three most likely points for kidney stones to become lodged and why?
Uteropelvic junction
Pelvic inlet - As the ureters cross the common iliac vessels
Ureter entrance to bladder
These are the 3 constriction points along the course of the ureters
How much urine can the bladder hold?
Up to 600mL
How is the bladder connected to the umbilicus?
From the median umbilical ligament by the apex
How is the neck of the bladder fixed in place in males and females?
Males: puboprostatic ligament
Females: pubovesical ligament
Which relations to the bladder are the same in both males and females?
Anterior and lateral relations
What is the area called on the bladder which has smooth walls?
Where is it located on the bladder
The trigone
On the fundas/base
What are the three openings of the trigone
Two superior - right and left ureters
One inferior - exit of urethra
What is the muscle of the bladder called?
What kind of muscle is this?
Detrusor muscle
Specialised smooth muscle
How does the internal urethral sphincter differ in males and females?
Males - smooth muscle fibres under autonomic control
Female - functional sphincter with no muscle present, formed by the anatomy of the bladder neck
What kind of control is the external urethral sphincter under?
Voluntary control
What is the arterial supply to the bladder?
Internal iliac artery branches:
- superior vesicular
- inferior vesicular (males only)
- vaginal arteries (females only)
What is the venous plexus called that drains the bladder?
Vesical venous plexus
Where does the sympathetic nerve supply to the bladder come from?
Preganglionic fibres arise from spinal cord T10-L2
Fibres are transmitted in the lumber splanchnic nerves
Preganglionic fibres terminate in the hypogastric ganglion
Postganglionic fibres arise from the nerve cell bodies in the hypogastric plexus
What does sympathetic innervation do to the bladder?
Relaxes the detrusor muscle
Closes the internal sphincter
Promotes urine retention
Where does the parasympathetic supply to the bladder arise?
From spinal cord segments S2-S4
Fibres are transmitted in the pelvic splanchnic nerve
Fibres pass through the inferior hypogastric plexus without synapsing
What does parasympathetic supply to the bladder result in?
Contraction of the detrusor muscle
Inhibition of internal sphincter - causes it to open
This stimulates micturition
Which nerve supplies somatic innervation to the bladder?
Which part does it innervate?
Pudendal nerve (S2-S4) Innervates the external urethral sphincter
What is the pelvic pain line?
What kind of pain afferents come from above and below?
Above the pelvic pain line - pelvic organs in contact with peritoneum, pain follows sympathetic fibres
Below the pelvic pain line - pelvic organs that do not contact the peritoneum, pain follows parasympathetic fibres
How long is the female urethra?
4cm
What are skene’s glands?
Two small paraurethral mucous glands associated with the lower end of the female urethra
How many times does the male urethra bend along its course?
Twice
How long is the male urethra?
20cm
What are the 4 parts of the male urethra?
Preprostatic
Prostatic
Membranous
Spongy
In which part of the male urethra is the internal urethral sphincter?
Preprostatic part
In which part of the male urethra is the seminal colliculus located?
The prostatic part
Where do the prostatic glands drain into the urethra?
At the prostatic sinuses in the prostatic part of the urethra lateral to the urethral crest
Which part of the male urethra contains the external urethra sphincter?
Membranous part
Which part of the male urethra do the bulbourethral glands open into?
The spongy part
What are the four histological zones of the prostate?
Central zone
Transitional zone
Peripheral zone
Fibromuscular structure
Which zone of the prostate is prostate carcinoma most likely to occur?
The peripheral zone
In which zone of the prostate would you most likely get benign hyperplasia (BPH)?
Transitional zone
Which zone of the prostate is felt on a DRE through the rectum?
The peripheral zone
