Neural Control of Pelvic Function 6 Flashcards
Outline the coordination of somatic, sympathetic and parasympathetic activity in sexual function.
1
Q
What is a major region for the neural control of sexual behavior?
A
- Medial preoptic region of the hypothalamus
- lesions to this area in animals diminish or abolism sexual behavior
- stimulation here elicits sexual behavior
- many sexual responses and sexual motivation remain after lesions
- input from limbic, olfactory, and cortical regions
- Receptors in the medial preoptic region
- for androgens
- for estrogen
- for progesterobne
- allows integration of hormonal status and behavior
- A common view is that sexual function is organized at the spinal level and these responses are under mostly descending control
- mostly inhibitory
- some facilitory
2
Q
What are the neural mechanisms for male arousal?
A
- Penile vasodilation mediated by the cavernous nerve
- originates in the pelvic plexus and travels alongside prostate and urethra
- contains both sympathetic and parasympathetic postganglionic neurons
- Vasodilation is primarily mediated by nitric oxide
- Contraction of penile muscles is mediated by pudendal nerve
- Erection can be mediated by both direct genital stimulation (reflexogenic erection) or by CNS control (psychogenic erection)
- genital sensory information is carried primarily by the pudendal nerve
3
Q
What are the neural mechanisms of emission in the male climax?
A
- Both sympathetic and parasympathetic mechanisms are involved in emission
- Glandular secretion is increased by stimulation of fluid production by both ACh and NE
- contraction of myoepithelial cells from NE
- Ductus deferens motility is increased by both NE and ACh
4
Q
What are the neural mechanisms involved in ejaculation of the male climax?
A
- Stereotyped response mediated by a central pattern generator
- Response is elicited by a combination of genital sensory stimulation and supraspinal control
- Sensory fibers ravel in the pudendal nerve
- Pudendal nerve also mediates contractions of muscle
- Ejaculation generated in the caudal spinal cord
- Spinal pattern generator under tonic descending inhibition
- Mechanisms mediating male refractory period are unknown
5
Q
What are the neural mechanisms that are involved in the female climax?
A
- Little known of mechanism
- Likely identical to males
- Response produced by pattern generator elicted by genital and CNS stimulation