Wednesday, December 21, 2022
Gallbladder Sinew Channel, Side bending and Rotation
Sunday, December 11, 2022
Reflections from Cadaver Lab: Week 2 Day 5
Reflecting on my fifth day of week two teaching the 2022 Cadaver Lab.
On the fifth day of lab, we have the donors turned back into a prone position to complete the dissection of the posterior portion of the body. This is actually the first half of the day. For the second half, students are able to finalize any project that they are working with and start exploration to study anything. This week involved exposing the cranial cavity and brain, cutting the vertebral arch to expose the spinal cord and cauda equina, exploring the ligaments of the hip and knee, and dissecting deep into the medial thigh to get to the very deepest layer here. Here are some reflections:
- I am teaching, so am back and forth between tables constantly to help advise, help with the dissection, and help identify structures. In some ways this slows down for me during the second half of the day. My colleague that I teach with frequently opens the cranial cavity and highlights structures of the brain. As one would expect, this generates a lot of enthusiasm, and I am usually working to complete a project while he is doing this. This year, I reflected back the muscles of the hip down to the level of the ligaments. This provided a very nice model for these ligaments. I was also able to reflect back to the deepest layer of the groin and expose the obturator externus and also get a very good model of the obturator nerve which could then be followed from the abdominal cavity medial to the psoas and into the medial thigh. This nerve has something to do with the Kidney divergent channel. I feel this is the case because I think that the du mai has something to do with the nerves which exit from the lumbar plexus and wrap around the abdomen to innervate the lower portion of the abdominal muscles such as the internal and external obliques and the transverse abdominis. Specifically, the ilioinguinal, iliohypogastric and subcostal nerve follow the trajectory and describe function of this vessel. I wrote a post about this recently, and you can find this here.
The Kidney divergent channel is said to intersect with the dai mai at L2, which is exactly what the obturator nerve does. This is why I feel it is part of the Kidney divergent channel, at least the lower half of this secondary channel. - The lumbar plexus is houses between the anterior and posterior layers of the psoas major. We discuss this on an online recorded class available here. I was able to reflect back this anterior layer of the psoas and reveal the lumbar plexus nerves. On this specimen, the psoas was different than I have seen. It had two main grouping of fascicles and almost looked like two separate muscles. This muscle has an interesting fascicle arrangement all of the time, but this was different. I had two distinct branches that then blended with the iliacus muscle. The best I could tell was that the anterior and posterior layer were more distinct from each other than usual, but I was not able to return and figure this out because I got called to other areas for assistance.
- Being able to move and palpate a specimen while seeing the structures helps inform what you feel. For instance, mobilizing the hips with just the ligaments holding the hips helps you feel what just the ligaments feel like in this movement. Or doing a varus and valgus stress test with the ligaments exposed helps refine this test. And doing Lachman;s test while watching a torn ACL move gives so much information.
Thursday, December 8, 2022
Reflections from the Cadaver Lab: Week 2 Day 4
Reflecting on my fourth day of week two teaching the 2022 Cadaver Lab.
Each year I teach this cadaver lab, I plan on posting some reflections at the end of each day. I did pretty well this year, posting for days 1-4 of the first week. And then I got off track. This is for two reasons. 1) Dissection lab is very tiring both mentally, but also physically. One is standing the entire day and working over a table, accounting for the physical aspect, but it is also mentally tiring due to the sustained concentration. This is especially true when you are teaching. 2) There is really so much to highlight that at the end of the day it almost makes it too difficult to remember what I was planning to post when I get home. This is made worse by point number one.
Day 4 is the same as last week. It is the day that evisceration occurs and the organs are studied. It is not only this, however. The dissection continues into deeper layers of the anterior neck and extremities so that you can follow myoneurovascular structures from the neck and into both the thoracic cavity but also the upper extremities and you can follow myoneurovascular from the abdominal cavity into the lower extremities. Day 4 is really the culmination of the week up to this point.
Here are some reflections:
- There are many things I teach to acupuncturists regarding the channel sinews (jingjin) and their myofascial connections. Reflection of the biceps brachii is a great example of this. With the biceps reflected, you get a great view of the coracobrachialis and the brachialis. The brachialis has two myofascial connections. On the lateral side of the humerus, it has a clear myofascial connection to the deltoids, especially the anterior fibers. Following this path highlights the a deep branch of the Lung sinew channel. However, the brachialis also has a clear myofascial connection to the coracobrachialis which highlights the Pericardium sinew channel. This connection is great in anatomy texts, but much more obvious on a fresh tissue dissection when you can put tension into these myofascial planes. Visually it is apparent, but the tactile portion helps solidify the understanding when considering how injury can affect this plane.
- The IT band is really a fascinating structure when you do dissection. It is really almost abstract because, to view this structure, you have to remove the fascia lata (the deep fascia of the thigh) while retaining the IT band. This means you cut an artificial line on the anterior and posterior border and remove the fascia lata off up to this line you created. There is a guideline regarding where you make this line and that is the TFL muscle. The ITB does have some variability in tension from specimen to specimen, but nothing like what you feel when you palpate patient's lateral thighs. There is far more variation with patients. So, all of these tight IT bands really has more to do with the baseline tension in the TFL and/or the underlying vastus lateralis. I think the vastus lateralis is the more likely thing practitioners are palpating. When reflecting the IT band, you follow under the TFL to the ASIS to reflect both together. You have to find the fascial plane between the TFL and the underlying gluteus medius when doing this. It is hard to differentiate. Which is also the case when you palpate and needle these structures on patients. I think many times, clinicians are sensing the gluteus medius and advancing the needle to this muscle when they think they are treating the TFL.
- The plantar foot is organized in layers which can be followed in dissection. The superficial layer has the plantar fascia which has a very clear connection to the underlying flexor digitorum brevis, but it also has a clear connection to the adductor hallucis. This is the layer of the Kidney sinew channel. The next layer involves has the flexor digitorum longus, quadratus plantae, and lumbricals. This is the layer of the Liver sinew channel. The final layer includes the tibialis posterior, flexor hallucis and adductor hallucis. This is the layer of the Spleen sinew channel. These layers are well depicted in Netter and other anatomy atlases because the plantar foot is so clearly organized this way in dissection. The channels would follow would also be associated with this order.
- I saw a pretty odd anomaly of the psoas major. I will look a bit closer and try to describe tomorrow.
Thursday, December 1, 2022
Reflections from the Cadaver Lab: Week 1 Day 4
Reflecting on my fourth day teaching this year's Cadaver Lab.
Day four of lab is really the point where you start to get into the channels. This happens a bit on day two and three also, but four is much more obvious. We are going more into the neurovascular and myofascial structures, but you are also evicerating. This current class is for Physician Assistant students, so I don't discuss the channels much, but they are always in my mind and here are some anatomical thoughts on the channels that I was observing today.
The greater omentum gives us a view of the Lung channel. Look at the image of this channel in Deadman (or, really any good illustration) and also follow the description and you will see that this channel originates in the region of the stomach and then descends and connects with the large intestine. This is exactly what the greater omentum does. It hangs off of the greater curvature of the stomach and drapes over the abdominal organs. If you lift the bottom of this structure upwards to look at the under surface, you see that this anchors the transverse colon. There is a really interesting physiological thing that connects this structure to the Lungs (capital L meaning that I am discussing the TCM view of the Lung). The greater omentum can move and cover assist when there is infection on the abdominal cavity. It has been described as the abdominal policeman since is has an immune system cells and it surveils the region, mobilizes and covers areas of infection and walls it of with immunologically active tissue. Sounds a bit like wei qi to me!
On the topic of the Lung channel, I was able to get a really great view of the Lung sinew channel. I was demonstrating dissection of the anterior forearm muscles and preparing for reflection of the superficial muscles such as the palmaris longus, flexor capri radialis, and ulnaris. The arm was up overhead to expose the anterior forearm. Removing crosslinks from the ulnar surface of the FCR keeps the lacertus fibrosis (bicipital aponeurosis) intact and you can see such an obvious fascial plane between FCR and the biceps brachii. I pointed out the myofascial plane which interested the students, but I think my acupuncture colleagues would have appreciated it much more.
Another channel I observe when working with a student was the Liver channel and a branch of the Stomach sinew channel. I was helping the student reflect back the quadricep group from the innominate and femur, but keeping them intact as a group and keeping the patellar ligament intact. This requires going medial/under the IT band to remove the vastus lateralis from the linea aspera and other femoral attachments. And it requires going lateral to the medial intermuscular septum of the thigh (the septum between the vastus medialis and adductors) to remove the vastus medialis from the linea aspera and other femoral attachments. Then it requires lifting all of the quadriceps off the femur. When entering into the medial intermuscular septum, you are in the Liver channel. As you follow this space proximal, you end up between the vastus medialis on one side and the distal iliopsoas on the other. You are also in very close proximity to the neurovascular structures in the femoral triangle.
When you do this on the lateral side, you are cutting the vastus lateralis away from bone. This is a muscle of the Stomach sinew channel. At its most proximal, you need to cut this muscle away from fibrous attachments to the glutes. This is the lateral branch of the stomach sinew channel which is said to connect with the shaoyang channels. It then runs up the gluteus medius and minimus fascia to connect with the lateral raphe, a structure in the thoraculumbar fascia that is the lateral border of the quadratus lumborum and iliocostalis lumborum.