Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
36 Cards in this Set
- Front
- Back
|
Does anything change about urine after it leaves the collecting duct?
|
no
|
|
|
What is the ureter's function?
|
Carries urine from the renal pelvis to the bladder.
|
|
|
Structure of ureter - what are 4 layers from inner->outer?
|
-Lined w/ transitional epithelium over submucosal layer
-Inner longitudinal muscle layer -Outer circular muscle layer |
|
|
What are the contractions of ureteric muscle like?
|
Peristaltic contractile waves that originate from the proximal portion
|
|
|
How frequent are the peristaltic waves of the ureter?
|
2-6 /min
|
|
|
What triggers peristaltic contraction of the ureter? (3 things)
|
-Mechanical stimuli (stretch)
-Chemical stimuli -Membrane depolarization |
|
|
Does ureteric peristalsis require innervation?
|
no
|
|
|
What types of nerves innervate the ureter?
|
-Symp
-Parasymp -Autonomic pain fibers |
|
|
What is the ureter pathway like as it enters the bladder?
|
-Enters low/posteriorly
-Crosses obliquely through the detrussor muscle |
|
|
What covers the uretereal orifice?
|
A flaplike mucous membrane valve
|
|
|
What is the function of the flaplike valve and oblique pathway of the ureter?
|
Prevents urine reflux
|
|
|
What are the 2 main parts of the bladder?
|
-Body
-Neck |
|
|
What is the muscle of the bladder?
|
Detrusor
|
|
|
How much can simultaneous contraction of the detrusor increase bladder pressure?
|
40-60 mm Hg
|
|
|
How long is the bladder neck? What is it made of?
|
2-3 cm; composed of detrusor muscle and elastic tissue.
|
|
|
What is the function of the bladder neck?
|
It serves as an internal sphincter to prevent bladder emptying until it reaches a certain critical threshold.
|
|
|
Primary nerve supply to the bladder:
|
Pelvic nerve
|
|
|
Fibers in the pelvic nerve:
|
-Sensory nerves
-PNS Motor nerves |
|
|
What do the sensory fibers of the pelvic nerve detect and how do they respond?
|
Sense Stretch - initiate bladder emptying reflex.
|
|
|
What muscle do the PNS motor nerves innervate?
|
Detrusor
|
|
|
What somatic nerves innervate the external sphincter?
|
Pudendal
|
|
|
What is a cystometagram?
|
The pressure:volume curve for the bladder.
|
|
|
What is the compliance of the bladder at low volumes?
|
High
|
|
|
How do you know the bladder is highly compliant at low volumes?
|
Because it can hold a lot of volume with minimal changes in pressure.
|
|
|
What happens as the bladder fills with volume?
|
Its compliance decreases so pressure begins to increase rapidly
|
|
|
What are Micturition waves?
|
Periods of increased luminal pressure in the bladder that can reach up to 100 cm H2O and last seconds up to a minute.
|
|
|
What are micturition waves initiated by?
|
Sensation of stretch by stretch receptors in the bladder wall.
|
|
|
Where does the impulse go when stretch receptors sense increasing stretch?
|
To the sacral spinal cord, then back to the bladder via the PNS pelvic nerve
|
|
|
What happens to the micturition waves as the bladder fills?
|
They increase in frequency and strength.
|
|
|
What can happen to micturition waves?
|
They can cease for minutes up to an hour, but will come back!
|
|
|
What happens when micturition waves become powerful enough?
|
They initiate a reflex through the pudendal nerves to inhibit the external sphincter.
|
|
|
What will happen when the pudendal reflex is stimulated?
|
Urination - unless your voluntary control is greater.
|
|
|
Is micturition completely reflex?
|
No; higher cortical centers exert the final control.
|
|
|
How do higher centers have the final control of micturition?
|
They partially inhibit micturition reflexes by voluntary contraction of the external bladder sphincter.
|
|
|
How is voluntary urination initiated?
|
1. Abdominal muscles contract
2. Bladder pressure increases 3. Higher centers simultaneously stimulate micturition reflex and inhibit the external sphincter. |
|
|
So the main function of the micturition reflex is really to:
|
Empty the bladder.
|
