Urinary System (w23) Flashcards
What is the function of ureters ?
They carry urine to the urinary tract
What is the urethra ?
The tube between the bladder and external environment.
What the function of the bladder ?
It stores urine until convenient to void.
How to the ureters pass urine ?
By peristaltic waves (smooth muscle)
How is the back flow of urine prevented ?
By ureterovesical valves
What are the two parts the bladder can be divided into ?
1) Body (lying above ureteral orifices)
2) Base (Consisting of trigone and bladder neck)
What is the trigone in the urinary bladder ?
The area between uretal orifices and internal sphincter.
How many reflexes coordinate activities of bladder smooth muscle, plus striated and smooth muscle of the urethra >
35 +
When is the micturition reflex activated ?
It is activated when the urinary bladder is stretched.
What are the two phases the bladder switches between in the micturition reflex ?
The storage phase and the voiding phase
During the storage phase of the micturition reflex, why does the pressure stay low as the bladder fills ?
Due to a highly elastic nature
What role does the urethra play during the voiding phase of the micturition reflex ?
The urethra play an excitatory role which maintains flow till the bladder is empty.
Describe the steps of the micturition reflex …
1) it is activated by stretch of urinary bladder (trigone)
2) this eventually causes Action potentials to travel along sensory nerves in the pelvic nerve to the sacral region of the spinal cord
3) these action potentials are then integrated at spine - AP then travel Along the parasympathetic nerve to the urinary bladder
4) the bladder then contracts.
5) the external sphincter is normally contracted as result of the somatic motor nervous system
- Decreased AP cause Urethral sphincter to relax
What is another way the micturition reflex can be activated ?
Can be activated by irritation from bacterial infections in the urinary bladder.
- occurs when bacteria pass up along the urethra and enter and multiply within the bladder causing inflammation.
What is a term to describe the stretch of the urinary bladder which activates the micturition reflex ?
Trigone
