Micturition
The micturition reflex is a spinal cord-mediated process controlled by autonomic and somatic nerves:
What our notes say
- The micturition reflex is a spinal cord-mediated process controlled by autonomic and somatic nerves: (MEDICAL PHYSIOLOGY II ESsays)
- Wairimu, 4 years, has a 2-day history of lower abdominal pain, painful micturition and a low-grade fever. (Paediatrics main exam (MBPE 4300): 24 January 2022, Paper One, 100 MCQs, 2 short)
- Painful micturition with fever suggests a urinary tract infection, with white cells and bacteria in the urine. (Paediatrics main exam (MBPE 4300): 24 January 2022, Paper One, 100 MCQs, 2 short)
- | Frequency of micturition | From congestion and pressure on the bladder; it returns late in pregnancy when the head descends | (Diagnosis of pregnancy)
- Vasovagal syncope — autonomic overactivity from emotional/painful stimuli, or cough ("cough syncope")/micturition ("micturition syncope") (CVS History & Physical Exam: Symptoms, Chest Pain & Syncope)
- Vasovagal syncope — autonomic overactivity triggered by emotion, pain, coughing, micturition (CVS History, Physical Exam & ECG: Master Clinical Assessment)
Study material on Micturition
- Master First-Year Anatomy: Must-Know Essays & Key Concepts
- MEDICAL PHYSIOLOGY II ESsays
- END YEAR PP1 & PP2 2025 Physiology: MCQs for Medical School Exams
Practice questions on Micturition
Micturition occurs due to ---
- Relaxation of detrusor muscle
- Contraction of urethral sphincters
- Parasympathetic activation to bladder
- Somatic motor neuron activation
- Occurs only after chronic exposure
Answer: C.
During voluntary inhibition of micturition when the bladder is full, which of the following responses occurs? ---
- Inhibit the pelvic nerve
- Inhibit the pudendal nerve
- Inhibit the hypogastric nerve
- Inhibit the parasympathetic system
- to prevent detrusor contraction. The pudendal nerve is kept active to maintain external sphincter contraction.
Answer: A.
First stimulation in the micturition reflex occurs when the volume of urine in the bladder reaches ---
- 150 ml
- 300 ml
- 560 ml
- 700 ml
Answer: A.