Sexual Arousal Pathways

The sexual response system is fascinating and incredibly complex. It has been somewhat researched and is subject to ongoing research which we will continue to follow with interest.

We are not attempting to explain the whole system here! In this section, we are focussing on the Psychogenic and Reflexogenic Sexual Arousal Pathways as a means of explaining how these neural pathways coordinate the body's response to stimuli.

References:

Elliott, S. L. (2008). Neurophysiology of sexual spinal reflexes. Springer EBooks, 2820–2823. https://doi.org/10.1007/978-3-540-29678-2_3936

Komisaruk, B. R., Whipple, B., Crawford, A., Grimes, S., Liu, W.-C., Kalnin, A., & Mosier, K. (2004). Brain activation during vaginocervical self-stimulation and orgasm in women with complete spinal cord injury: fMRI evidence of mediation by the Vagus nerves. Brain Research, 1024(1-2), 77–88. https://doi.org/10.1016/j.brainres.2004.07.029

Krassioukov, A., & Elliott, S. (2017). Neural Control and Physiology of Sexual Function: Effect of Spinal Cord Injury. Topics in Spinal Cord Injury Rehabilitation, 23(1), 1–10. https://doi.org/10.1310/sci2301-1

Rees, P. M., Fowler, C. J., & Maas, C. P. (2007). Sexual function in men and women with neurological disorders. The Lancet, 369(9560), 512–525. https://doi.org/10.1016/s0140-6736(07)60238-4

The animation below illustrates the Psychogenic Pathways Response, where seeing, thinking, smelling, touching or tasting sends information from the brain down the spinal cord and results in engorgement of the clitoris.

Reflexogenic Pathway

The reflexogenic pathway is all about how physical touch and stimulation trigger the arousal process. Unlike the psychogenic pathway, which starts in the brain, this one happens automatically when certain areas of the body are touched—especially the genitals.

How it works

When the genitals or surrounding area are touched, the skin’s nerve endings pick up on it.

This can include sensations like light touch, pressure, temperature, vibration or any other physical stimulation.

Internal sensations can also send signals, such as movement of internal organs such as the uterus or ligaments during intercourse or pressure from the bladder.
The nerve signals don’t go straight to the brain first. Instead, they go to the S2 to S4 region of the spinal cord, which acts as a relay centre.

The sacral spinal cord (in the lower back) plays a key role here—it processes the touch and immediately sends signals back to the genitals to trigger an automatic response.
For people with vulvas: The clitoris and vaginal tissues swell, lubrication increases, and sensitivity heightens.

For people with penises: The erectile tissue of the penis fills with blood, leading to an erection.
This process happens without conscious brain involvement—it’s a built-in reflex of the body.

The brain can sometimes enhance or partly inhibit the response. If a person’s emotional state allows for psychogenic arousal to occur at the same time, the arousal process can become stronger. Emotions like stress of anxiety may partially inhibit the body’s automatic arousal.

The brain’s ability to shut this reflex down is limited, and it is completely normal for the body to automatically respond to touch, including non-consensual touch.

It shows that the sexual response of the body isn’t just psychological —it can be an automatic reaction to touch.

This explains why people with spinal cord injuries can still experience physical arousal, even if they’ve lost sensation.

In non-consensual experiences of touch, it’s important to understand the body’s automatic arousal reflex, which is separate to conscious choice or enjoyment.

The animation below illustrates the Reflexogenic Pathways Response, which takes place at the S2 to S4 part of the spinal cord. In response to someone being touched on the vulva, a message is sent to the spinal cord returning an immediate reflex response directly back from the S2–S4 region to the area, starting the engorgement process. This is an automatic response to sensation in the genital area – without involvement from the brain. The response is not under voluntary control and is not linked to consent or enjoyment. (Sexual non-concordance).

An important note regarding consent:

The physical arousal response of the body (an erect penis or wet vulva/engorged clitoris) does not require nor imply consent to be touched. This is super important for all people to understand. The only way to know if there’s consent is to ask and communicate. We encourage everyone to learn more about practicing consent, to ensure it’s present in all interactions.

Arousal Non-Concordance

Arousal non-concordance can happen when the brain finds something sexually appealing, but the body doesn’t respond by becoming physically aroused. This can be due to multiple factors such as stress, hormonal imbalances, trauma or shame. It can also happen during a reflexogenic arousal pathway, if the body becomes aroused automatically whilst the mind isn’t turned on. Research has shown that the concordance between genital response and subjective arousal within the brain to be different between people assigned male at birth (AMAB) and people assigned female at birth (AFAB).

There is approximately a 50 percent overlap between what AMAB people’s genitals respond to as ‘sex-related’ and what their brains respond to as ‘sexually appealing’.
There is approximately a 10 percent overlap between what AFAB people’s genitals respond to as ‘sex-related’ and what their brains respond to as ‘sexually appealing’.

Psychogenic Pathway

The psychogenic pathway in sexual response is all about how the brain and emotions influence arousal—without any direct physical touch. It’s different from the reflexogenic pathway, which kicks in when there’s actual physical stimulation.

How it works

Thoughts, fantasies, and memories can trigger the arousal process.

Sensory input from all five senses—things you see, hear, touch, taste, and smell— also play a big role (like noticing an attractive person, watching a steamy scene in a movie or eating a food that reminds you of a positive sexual experience).

A person’s emotional state—feeling relaxed, excited, or turned on—also plays a big role.
The limbic system (the brain’s emotional centre) processes those emotional and sensory signals.

The hypothalamus, especially a part called the medial preoptic area (MPOA), helps turn mental arousal into a physical response.

The dopamine system (the brain’s pleasure and reward network) releases dopamine, the “feel-good” hormone, which drives continued attention or engagement.
The brain sends messages through the nervous system (T12 to S1 region of the spinal chord) to the genitals.

This happens through both the sympathetic and parasympathetic nervous systems, which control things like blood flow and sensitivity.
For people with vulvas: The clitoris and vaginal tissues get more blood flow, causing swelling, lubrication, and increased sensitivity.

For people with penises: More blood flows into the erectile tissue of the penis, leading to an erection.

Thoughts, fantasies, and memories can trigger the arousal process.

Sensory input from all five senses—things you see, hear, touch, taste, and smell— also play a big role (like noticing an attractive person, watching a steamy scene in a movie or eating a food that reminds you of a positive sexual experience).

A person’s emotional state—feeling relaxed, excited, or turned on—also plays a big role.