Neural Control of Pelvic Function 7 Flashcards
Describe the sequence of events in male and female sexual arousal and climax.
1
Q
What are some of the physical events that occur in male arousal?
A
- Penile erection mediated by vasodilation of erectile tissue, producing tumescence
- Contraction of striated penile muscles leads to rigid erection
- Arterial blood flow increases several fold during erection
- arteries are responsible for tumescence, not veins
- Penile volume increases 80-200 mL - pressures can be as great as 1500 mmHg
2
Q
Describe the process of detumescence.
A
- Active process mediated by vasoconstriction
- Due to NE released from non-cavernous nerve sympathetic postganglionic fibers
- caudal sympathetic chain
3
Q
What is the mechanism of vaginal lubrication in female arousal?
A
- First sign of sexual arousal in females
- 5-15 seconds after stimulation begins
- Probably active transport driven
- contains high K+, low Na+ compared to plasma
- Mechanism of production is unknown
4
Q
What is the mechanism of clitoral erection in female arousal?
A
- Similar to penile erection
- Vasodilation mediated by the cavernous nerve
- striated muscle activity probably not important
5
Q
What is the mechanism of genital vasocongestion during female arousal?
A
- Tissue becomes greatly engorged with blood
- Due to great increase in blood flow (vasodilation) and maybe vasoconstriction
- Autonomic mechanisms are unclear
- Returns to basal state following orgasm
6
Q
What are the physical events that occur during the emission phase of male climax?
A
- Strong contraction of the internal and external urethral sphincter
- Fluids from the prostate, seminal vesicle, and ductus deferens enter into the prostatic urethra
- Pressure within the urethra increases due to fluid and contraction of both smooth and striated muscle contraction
7
Q
What are the phsyical events that lead to ejaculation in the male climax?
A
- Internal urethral sphincter remains closed
- When volume/pressure reaches a certain point, external urethral sphincter opens
- either can be reflexively or volunterily
- Seminal fluids ejected into the urethral bulb
- Powerful, rhythmic contractions of the bulbospongiosus muscles eject the semen
- Simultaneous contractions of ischiocavernosus muscle and external anal and urethral sphincters
8
Q
What are the physical events that occur during the female climax?
A
- Consists of rhythmic (3-10) contractions of the perineal muscles
- In general, physiology very similar to males