B10 Week 2 Flashcards
How does urine form and travel?
Urine forms in the kidneys and collects in the renal pelvis. It travels down the ureters to be stored in the bladder and excreted via the urethra
How does urine travel in the ureter?
Entry of urine into renal pelvis causes it to dilate. Induces pacemakers to produce action potential in ureter for peristaltic contractions to propel urine.
What are the divisions of the ureter?
Renal pelvis
Abdominal
Pelvic
Intramural
What are the natural ureteric constrictions?
Pelvi-ureteric junction
Bifurcation of common iliac artery
Vesico-ureteric junction
What is the pelvic-ureteric junction?
Area where the renal pelvis joins to the ureter.
What is the vesico-ureteric junction?
Area where ureter enters the bladder. Obstruction can occur here if the ureter is too short via Paquin’s law.
What is the blood supply to the ureter?
Segmental based on the ureter level.RGCI
Renal pelvis level: renal artery
Abdominal level: gonadal artery (testicular/ovarian)
Pelvic level: common iliac artery
Intramural level: internal iliac artery
What is the lymphatic drainage of the ureter?
Para-aortic lymph nodes
What is the innervation to the ureter?
Ureteric plexus in T11-L2, derived from renal, aorticorenal and superior and inferior hypogastric plexus.
T11-L2 is the sympathetic innervation.
S2-S4 for parasympathetic innnervation.
What is the sympathetic innervation of the ureter?
T11-L2
What is the parasympathetic innervation to the ureter?
S2-S4
How does urine enter bladder?
Enters the base of the bladder, partially covered by peritoneum.
What are the features of the bladder?
Contains rugae in bladder wall in order to expand and avoid changes in internal pressure.
What is the bladder trigone?
Triangular shaped region at the bladder base. It is formed by the openings of the ureter posteriorly in the bladder and the opening of the urethra.
What are the features of the trigone?
It has a smooth surface due to its mesodermal origin, as well as being less mobile and more sensitive to pain. The rest of the bladder is endodermal origin.
What is the lymphatic drainage of the bladder?
Para-aortic nodes and internal iliac nodes
What affects sensation in the bladder?
Suppression of nerve impulses due to bladder being empty. Reduced pain sensation upon empty bladder.
Parasympathetic innervation to the bladder
S2-S4
Stimulates the contraction of the detrusor muscle for bladder contraction. Inhibits the external urethral sphincter for micrutition.
Sympathetic innervation to the bladder
T10-L2.
Inhibits impulses to detrusor muscle to allow relaxation and storage of urine in bladder. Stimulates the external sphincter to prevent micrutition.
What is the innervation to the urethra?
Branches of the Inferior hypogastric plexus. This plexus is posterior to the urinary bladder:
Pudendal in females
Prostatic plexus in males
Innervation to male urethra?
Sympathetic, parasympathetic and visceral is delivered by the prostate plexus, a branch of the inferior hypogastric plexus which also controls the urethral sphincters.
What are the components of the male urethra?
Prostatic urethra: prostatic tissue surrounded by transitional epithelia
Membranous urethra: pseudostratified columnar epithelia and passes through the external urethral sphincter
Spongy urethra: surrounded by corpus spongiosum and transitions from pseudostratified columnar -> stratified squamous in glans penis
What is the lymphatic drainage of male urethra?
Internal iliac and deep inguinal nodes
What is the female urethra?
Much shorter than the male urethra and opens into a vestibule anterior to the vaginal opening.
What is the composition of the female urethra?
3 coats
Muscular coat: continuous with the detrusor muscle
Erectile coat: Surrounded by corpus spongiosus
Mucosal coat: Formed of stratified squamous epithelia which can produce mucus
What is the histology of the female urethra
Begins as transitional epithelia
-> Pseudostratified columnar
-> Stratified columnar
->Stratified squamous at external urethral orificie