Being a first year medicine student, part of our PBL curriculum involves Anatomy laboratory which revolves around the dissection of a cadaver which is acquired by the school from the unclaimed bodies at the City Morgue. Each group gets one cadaver to dissect for the whole school year and is responsible of its continuous preservation. We dissect the cadaver systematically based on whatever body system we are currently discussing.
Prior to being assigned a cadaver, we were given a bag of human bones to study because during that time, we were learning about the skeletal system.
The funny thing is that, since I had Nursing as my pre-med, I felt as though I knew what to expect because everything sounded so familiar, and it actually really is, but when I was actually there in the situation, I found myself lost in the stream of all the medical jargon that I encountered while going through my atlas. What was even funnier was when I was taking up nursing, the skeletal system was one of the easiest systems to tackle because it has a relatively basic purpose and once the sum of all its parts has been broken down, you realize the skeletal system is just common sense. This proved to be horribly horribly wrong in Medicine which was a completely different ball game altogether.
A few things I had to come to terms with.
- Every part has a name. Every part of that part has a name. Every line, crease, fold, indention, cavity, ridge, border, edge, side, bump, angle, point of connection and hole has a name.
- Every name must be learned and labeled.
- Every thing in the atlas must be found and compared to bones for verification. If not found in bone, try again.
- Failure to do so means failing practical exams, which is a moving exam where you are given 40 seconds to identify the part labelled.
- fossa – depressed area
- notch or incisure – an indentation on the edge of a bone
- crest – a projection
- peak – top
- suture – a type of joint in which the apposed bony surfaces are united by fibrous tissue, permitting no movement; found only between bones of the skull
- process – a prominence
- foramen – natural opening or passageway
- fissure – cleft or groove
- tubercle – nodule or small eminence
- ala – wing
- raphe – seam or line of union of the halves of various symmetrical parts
- pedicle – constricted portion or stalk
- dens – toothlike structure
this is a picture of the cranial base inferior view, from my atlas (Atlas of Human Anatomy 5th ed. By Frank H. Netter, MD)
this is a picture of the cranial superior inferior view, from my atlas (Atlas of Human Anatomy 5th ed. By Frank H. Netter, MD).
(I got the photo from the website though, which is http://www.netterimages.com/)
As you can see, everything is in great detail. Overly detailed actually. Even the ribs! So it is easy to imagine how much more there is to know, taking into consideration that the average adult human being has 207 bones in total.
Every time I go to the Gross Anatomy Lab, I always see these steel containers beside our lab tables. I asked one of my group mates what was in them and he said extra parts like arms and legs, so you can imagine my surprise when the day we were assigned our cadavers, the lab heads were walking around in boots with rubber gloves and rubber aprons wielding crowbars as they opened the steel containers to reveal bodies swimming in formalin and blood which they pried out and piled into a wheel barrow for distribution. We were told that the first thing that had to be done was to skin the cadaver. We were given a manual on how to dissect the cadaver and were told to read it because they expected us to do everything ourselves. Questions will be asked to us and not the other way around, anything that needed to be clarified would have to be cross-checked with the sample cadaver that had been skinned by our facilitators as a model.
I don’t think I will ever forget the smell of formalin. It burns your whole respiratory tract as you breathe. I was not faced with the apprehension that in front of me was a dead man, rather, I was bothered by the fact that I could feel my nasal hair coming to a singe.
Everyone, meet Bob.
I told my group mates we had to give him a name because I couldn’t hang around someone I didn’t know on a regular basis. It would be like hanging out with a stranger.
My group mates, not being used to my quirkiness yet, looked at me with expressions hinting towards “is this girl mad?”, “did she say she wanted to name our cadaver?!”, “what is she talking about?”, “how did she pass the CIM interview when she is clearly deranged?”
I looked at them and they looked back at me and I said we should call him Bob, because he looks like a Bob and he smells like a Bob and he’s cute like a Bob. Yes, I said cute. I find Bob cute. So they looked at me weirdly and verified if I thought our cadaver was cute. and I nodded my head. Since I would not relent and kept calling our cadaver Bob, everyone agreed his name would be Bob. (now, everyone from our batch calls our cadaver BOB. 🙂 )
The pictures above and below were taken during skinning.
we had to remove the fat and clean the area. I cut his hair so we could shave his scalp and remove the skin. The tricky part when it comes to skinning the skull is that there are a lot of nerves, arteries and veins attached to the epicranial aponeurosis, which is one of the 5 layers of the scalp and the goal is to preserve as much as you can so when you study, you get to visualize everything. Although most times, we had to make sacrifices. Such as when we were studying the brachial plexus (nerve fibers from the spine, through the neck and into the axilla). It was very difficult to preserve everything and visualize everything at the same time, so we preserved as much as we could and then cut through the layers so we could see everything else.
One of the hardest things we had to discuss, were the muscles. There are not only a multitude of muscles, but one of the components of studying the anatomy of the body’s musculature is the point of origin and insertion of the muscle with their blood supply, innervation and action.
Two examples of Common muscles with their Origin, Insertion, Blood Supply and Innervation:
- Pectoralis Major – ORIGIN: It arises from the anterior surface of the sternal half of the clavicle; from half the breadth of the anterior surface of the sternum, as low down as the attachment of the cartilage of the sixth or seventh rib; from the cartilages of all the true ribs, with the exception, frequently, of the first or seventh, or both, and from the aponeurosis of the Obliquus externus abdominis. INSERTION: This extensive origin the fibers converge toward their insertion; those arising from the clavicle pass obliquely downward and lateralward, and are usually separated from the rest by a slight interval; those from the lower part of the sternum, and the cartilages of the lower true ribs, run upward and lateralward; while the middle fibers pass horizontally. They all end in a flat tendon, about 5 cm. broad, which is inserted into the crest of the greater tubercle of the humerus. INNERVATION: It is supplied by the medial and lateral anterior thoracic nerves; through these nerves the muscle receives filaments from all the spinal nerves entering into the formation of the brachial plexus. ACTION: If the arm has been raised by the Deltoideus, the Pectoralis major will, conjointly with the Latissimus dorsi and Teres major, depress it to the side of the chest. If acting alone, it adducts and draws forward the arm, bringing it across the front of the chest, and at the same time rotates it inward.
- Deltoidius – ORIGIN: It arises from the anterior border and upper surface of the lateral third of the clavicle; from the lateral margin and upper surface of the acromion, and from the lower lip of the posterior border of the spine of the scapula, as far back as the triangular surface at its medial end. INSERTION: From this extensive origin the fibers converge toward their insertion, the middle passing vertically, the anterior obliquely backward and lateralward, the posterior obliquely forward and lateralward; they unite in a thick tendon, which is inserted into the deltoid prominence on the middle of the lateral side of the body of the humerus. At its insertion the muscle gives off an expansion to the deep fascia of the arm. INNERVATION: supplied by the fifth and sixth cervical through the axillary nerve. ACTION: raises the arm from the side, so as to bring it at right angles with the trunk. Its anterior fibers, assisted by the Pectoralis major, draw the arm forward; and its posterior fibers, aided by the Teres major and Latissimus dorsi, draw it backward.
Imagine having to know all the muscles of your body in 5 different categories. Not fun. The picture below shows us tagging the muscles of the lower extremities in yellow yarn.
Next week, we’ll be discussing Neuroanatomy. So Bob’s cranium had to be cut so we could extract the brain. Bob is a special case. Allow me to elaborate why. Compared to the other cadavers who died of intrinsic causes, Bob was shot in the head. The point of entry and exit of the bullet is quite evident and the pictures below show signs of Epidural Hematoma.
Bob has been reduced to a torso since we’re finished with the GIT, Respi, and Cardio, there will be no further need for his head because we have already extracted his brain. This is a photo of him before we discussed the aforementioned. Heart is clear as well as the diaphragm.
The last things we will discuss are Neuro and Repro. So Bob is internally empty and completely limbless at the moment. He shouldn’t even have his head anymore if we hadn’t grown so attached to him. I’ll miss Bob. Even if he looked like a Serial Killer, I always thought he was kinda cute.