Micturition Flashcards
Upper urinary tract
-components?
Calyces, pelvis, ureters
Bladder
-Function?
- Stores urine under low pressure
- Expels urine under high pressure
Urethra
- What is it?
- Function?
- A conduit for carrying urine from the body
- Its two sphincters control voiding
Urinary bladder and sphincters
-2 sphincters?
- Internal
- External
Urinary bladder
- Internal sphincter
- Type of control?
- Type of muscle?
- Where is it?
- Involuntary control
- Smooth muscle
- It is the wall of the bladder as it narrows toward the urethra
Urinary bladder
- External sphincter
- Type of control?
- Type of muscle?
- Where is it?
- Voluntary control
- Skeletal muscle
- Wraps around exterior of urethra where it joins bladder
Urinary bladder
-External sphincter-associated nerve?
Pudendal nerve
Urinary bladder
-Internal sphincter-associated nerve?
Pelvic nerve
Hypogastric nerve-slide 6?
?
Local Nervous Control
- Innervation of the urinary tract-afferent pathways for conscious bladder sensations
- Through which nerve or plexus?
- Through pelvic splanchnic nerve or hypogastric plexus
- S2-S4
Local Nervous Control
- Innervation of the urinary tract-afferent pathways for conscious bladder sensations
- Posterior columns?
Bladder fullness
Local Nervous Control
- Innervation of the urinary tract-afferent pathways for conscious bladder sensations
- Anterolateral columns?
Bladder pain
Reflex arc for the micturition reflex-sacral micturition center
-From bladder?
Bladder–>sacral detrusor nucleus–>Bladder?
Reflex arc for the micturition reflex-sacral micturition center
-From urethra?
Urethra–>sacral micturition center–>voluntary sphincter
Efferent nervous controls of the bladder and urethra
- Sensory fibers
- From?
- Activated by?
- From bladder wall, posterior urethra
- Activated by stretch
Parasympathetic fibers
- Neurotransmitter?
- Nerve?
- Functions?
- Cholinergic-acetylcholine
- From sacral micturition center S2-S4 (pelvic nerve)
- Stimulate detrusor muscle
- Inhibit contraction of internal urethral sphincter
Sympathetic fibers
- Neurotransmitter?
- Nerve?
- Functions?
- Neurotransmitter-adrenergic-NE
- Hypogastric nerve
- Inhibits detrusor constriction
- Constricts internal urethral sphincter
Somatic motor neurons
- Type of control?
- Nerve?
- Function?
- Voluntary control
- Pudendal nerve
- Constrict external urethral sphincter