Anatomy Nerd Alert
Y’all already know I’m a big ol’ anatomy nerd. It’s not like I hide it or anything. The anatomy of the pelvic floor happens to be one of my favorite things on which to educate people - ask any of my patients about the times I pull out my anatomy model, or my Netter’s Atlas of Human Anatomy (probably my favorite book I own), and they’ll confirm that I love sharing the details of how our body’s form and function work together!
Your pelvic floor isn’t a single structure. It’s actually a network of muscles, tendons, ligaments, and the bones that support them (aka, the pelvis and spine). We can also throw in nerves, blood vessels, and fascia as important supportive players in this network. Our pelvic floor is the “bottom of our barrel”, so to speak. If you look at the bottom of our pelvis, and therefore the bottom of our trunk, there are no hard, body structures actually holding in the contents of our abdomen. The bones of the pelvis are a framework for the intricate soft tissue structures which provide support and stability to our whole body. Those soft tissue structures, especially the muscles, fascinate me.
I love, love, love talking about the structure of the muscles of the pelvic floor. For today’s purposes, I’m going to talk about the pelvic floor anatomy of people with vulvas. (Peeps with penises, I promise to get to you, too!). There are 3 distinct layers of pelvic floor muscles. The first and second layers have some similarities in both form and function. Some of the muscles in these layers directly encircle the openings of the urethra, vagina, and anus, which tells you something about their function. These are the layers most people thing of when they do a pelvic floor muscle contraction (or, Kegel), since they are the layers that most directly close our openings. If you’re using your pelvic floor muscles to hold back urine, feces, or gas, these are the muscles you’re activating the most.
The third layer of the pelvic floor muscles acts more like a hammock and is located slightly deeper in the body than the first two layers. This group of muscles (part of which you may hear referred to as the levator ani muscle group) attaches in the front at the pubic bone, and slings around to the back where it attaches to the tailbone and sacrum. This layer is all about support. When we contract this layer of muscles, it raises up into our body slightly, cradling our pelvic organs as well as providing support to our abdominal contents. This action also plays an important role in continence - we’ll dive into that in a later post when we talk about the functions of the pelvic floor!
I really could go on and on (and on) about pelvic floor anatomy, but lots of people start completely glazing over when I do that. I’ll save the physiology (function) lecture for another day!
Do you want to nerd out with me about your pelvic floor? Hit me up - let’s chat!
