Please see an overview of the chakras in the Chakra 1 post.

Chakra 2 is experienced via the connective tissue and musculature outside of the bones, and through all the body’s fluids, including the blood, though the blood, arteries, and veins are experienced through the heart and lungs/4th chakra. While the pelvis and sacrum as bones live with chakra 1, as the holders of the body’s center of gravity and all life that ensues via the reproductive organs, these bones are jointly experienced by chakras 1 and 2. 

All the body’s joints, in fact, are experienced through chakra 2, and your mobility is a key function of chakra 2. Immobility, as Anodea Judith lists in her grid, is a “deficient” chakra 2, and extra mobility, i.e., collapse in the sacrum and hip joints, hyper extensivity, and other “hyper” mobility is “excessive” chakra 2. Take care with these labels, though, as they bring up emotions which are also chakra 2. Mobility and immobility have as much to do with thinking patterns as with anything else. Thinking patterns with respect to being stuck anywhere in the body have in fact most to do with the mind.

“Feeling stuck” in life is a key characteristic of imbalance in chakra 2, as you are arrested between what you believe you want and the reality of your being able to obtain or attain that want. Addictions of every kind, not limited to sex addiction, are also rooted in chakra 2. In this case, a bit like Einstein described insanity, you continue to go back to the same thing hoping for a different result. The addiction to the substance or action takes hold all over the body, but its root lies in the pelvis which is, also of note, the root of digestion.

In terms of the organ body, chakra 1 is the colon; chakra 2 is the intestinal body and, as aforementioned, the reproductive organs.

Your emotional life, as indicated via your own experience of your wants, desires, and ability/decision to create as well as procreate, all come from chakra 2. As I discussed in the workshop, any person's decision or ability to reproduce is not necessarily limited to chakra 2 but does take root there, as well as in chakra 1 which is tribe/genetics/DNA.