very special and very sacred opportunity
Dr Jeffrey Laitman, before entering the lab
In the afternoons we were privileged to spend time with prosections in the anatomy lab – looking and touching. A prosection is a cadaver that has been dissected priorly by anatomists for use in a setting such as a lab. Dr Laitman explained that Mt Sinai’s cadavers come from Mt Sinai’s anatomical gift program.
Seeing the inside of the human body was an awesome experience. Not awesome as in: oh, cool. Awesome as in: the human body is a marvel of interwoven connectivity and complexity, and I had almost 14 hours over four days to appreciate and learn thanks to the gift of the many donors.
TIP – After a sound night’s sleep you are a little taller in the morning b/c water returns to the intervertebral disc (IVD), allowing it to expand after spending the day compressing due to gravity.
Our vertebral column protects our spinal canal, which holds our spinal cord. The spinal cord is narrow! Okay, maybe no surprise to you, but given what our spinal cord does, I expected it to be a bit larger. The spinal cord is surrounded by cerebrospinal fluid.
Layered across our back are muscles that move our spine, our neck and our shoulders. My favorites, purely for their names, are the latissimus dorsi (Latin for broadest back), and the trapezius. Combined, they cover a swath of back from your neck to your shoulder to your side, and there is a set on both sides of your back. These plus the rest of your back muscles do a huge amount of work – just think of all your body movements – and when the muscles are contracted for long periods of time, they can get injured.
What do you think is the most common cause of muscle stress? ANXIETY & STRESS! Muscles contract when they are under stress, which can occur from physical or emotional issues. The pain from this initial muscle stress can cause secondary stress, which is when you are so upset about the initial discomfort that your emotional level gets upped and brings about additional pain.
Turns out, the least common form of back pain is a herniated disc, but it is the type of pain that seems to get the most traction (pun intended 😉 ) in stories about back pain.
There are 7 cervical vertebrae, beginning at the top of your spinal column, and most of them look like the one in this picture. Notice the two tiny holes in the body of the vertebrae? Those do not come with the vertebrae; they are drilled for wiring to hold reconstructed back bones together for the purpose of a model.
The cervical vertebrae does have holes, however, on either side. Each hole is within a portion called the transverse process, and the hole is called the transverse foramen (foramen is Latin for hole). The transverse foramen contains the vertebral artery, which supplies blood to the brain from the aorta.
Next in line are the 12 thoracic vertebrae, to which all ribs attach. There is a notch, called the transverse process, on either side of each thoracic vertebrae, and this is where the ribs attach. These vertebrae get progressively larger the further down the back they are located.
The 5 lumbar vertebrae make up the lower back. It differentiates from the previous two vertebrae in that there is no transverse foramen (hole) and no transverse process (notch), and the vertebral body is larger. You likely noticed, though, that all of the vertebrae have a triangular shaped hole underneath the vertebral body.
For these photos, the orientation of the vertebrae’s body is at the top, but that is not how they are situated in our spines. Try to imagine taking the bottom portion of each vertebrae (the portion where my fingers are in the second photo above) and lifting it up at a 90 degree angle, aligning the triangular holes of each vertebrae. All of the protrusions will face upwards or sideways. Those triangular holes of each vertebrae contain and protect our spinal canal.
At the bottom of our spines are two last sets of vertebrae. There are 5 or 6 sacral vertebrae fused together, followed by 3 or 4 coccygeal vertebrae also fused together.
THE BIRTH OF A NERVE
Every single nerve in our body travels from our brain through the spinal cord to a specific location within the body. To be sure, once free of the spinal cord, nerves branch off and form other nerves. Dr Laitman instructed us to think of a nerve as a phone cable.
The spinal cord floats within the vertebral canal, encased by the vertebral arch. At each vertebral level, dorsal and ventral roots exit the cord and merge within the intervertebral foramen to form a spinal nerve, which exits the foramen and travels to innervate various structures in the body. [from FAMI course materials]
Okay, so what does this mean? Dorsal and ventral come from Latin words (dorsum=back, venter=abdomen) and refer to the back and front. Roots are the beginnings of nerves. The intervertebral foramen (IVF) is the space between each vertebrae. Recall that foramen is Latin for hole. Innervate simply means to supply nerves to a part of the body.
And we have around 7 trillion nerves in our body. Wow.