Renal Physl 10 Flashcards
1
Q
What holds the urethra closed?
A
- Internal sphincter
* External sphincter
2
Q
What are the characteristics of the internal sphincter?
A
- Smooth muscle
- Part of the bladder wall
- Contracted at rest
3
Q
What are the characteristics of the external sphincter?
A
- Skeletal muscle
- Controlled by somatic motor neurons
- CNS stimulation maintains contraction unless urination occuring
4
Q
What is micturition?
A
A spinal reflex that response to conscious and unconscious input from higher brain centers
5
Q
What happens when the bladder fills with urine?
A
The walls stretch and activate stretch receptors that relay sensory information to the spinal cord. Parasympathetic neurons innervating bladder smooth muscle triggers contraction and increases pressure. At the same time somatic neurons relax which allow urine to exit
