Basic experiments in anatomical operations
Basic experiments in anatomical operations
Anatomical operation technology is an important link to improve anatomy teaching, scientific research, and cultivate the basic skills of anatomists. Through the practice of cadaver dissection, you can understand the human body's morphology and structure more profoundly, which is conducive to help memorize and consolidate the existing knowledge, and at the same time, it can also enrich the teaching specimens in the laboratory.
Operation method
Basic experiments in anatomical operations
Materials and Instruments
Cadaver Move I. Use of common anatomical instruments For more product details, please visit Aladdin Scientific website.
Dissecting tools Bone saws Bone chisels Bone scissors Hammer Grindstone
When dissecting, the frequently used dissection instruments are two dissection knives and two dissection forceps. Other dissecting instruments are used when needed.
(I) Dissecting knife
One is a rounded blade, used for cutting through the skin, severing muscles or large organs; the other is a pointed blade, used for trimming various important and delicate structures, such as blood vessels, lymphatics, nerves, and various catheters. There are four methods of holding the knife (Figure 16), which should be used according to the requirements of the operation. 
2. Pen manipulation The manipulation action mainly utilizes the interphalangeal, palm, finger and wrist joints to move gently and flexibly, with accurate and meticulous force, and it is the most widely used method of holding the knife.
3. Grasping type This method is less powerful, but more flexible, and is generally used for tough parts and longer tissue incisions.
4. Reverse picking This method is mainly used for small-scale skin, blood vessels and nerves in the opposite direction of the peeling and picking, which can avoid damage to the deep important structures.
(ii) Anatomical forceps
Dissecting forceps without teeth are often used, and those with teeth are seldom used, and can be used only when peeling off the skin or clamping the structure to be removed. As for nerves, blood vessels and muscles, the use of toothed forceps should be prohibited to avoid severing or damaging blood vessels and nerves.
The method of holding the forceps is similar to the pen-type method of holding the knife.
(iii) Sharpening
"If you want to do a good job, you must first sharpen your knife". Without a sharp dissection knife, the production of specimens will not be fast and good. Therefore, when dissecting a cadaver, we should often sharpen the knife, so that the knife is sharp. Commonly used grinding stone has coarse, fine two kinds, generally use fine grinding stone can be. In the knife edge has a gap or the tip of the knife blunt, only with a coarse grinding stone grinding, and then processed on the fine grinding stone. Grinding, hold the knife to maintain a smooth, even and solid force, the knife edge close to the grinding stone, the knife surface slightly tilted, the back of the knife slightly away from the stone surface for a long distance back and forth push. Both sides of the knife should be basically equal to the number of times the knife is ground, to avoid the blade to one side of the skewed. Sharpening the knife, but also at any time to the grinding stone with water or oil, to prevent dry grinding occurs at high temperatures, so that the knife edge annealing softening.
Second, the operation should pay attention to matters
1. Design of dissection program At present, the source of cadavers is more difficult, and there are not many opportunities for dissection of cadavers, therefore, it is necessary to plan and prepare well in advance. What needs to be dissected, what to observe or what kind of local specimens should be done in mind, and at the same time, the necessary anatomical knowledge should be previewed. When dissecting, it is necessary to master the correct operation method, to understand the initiation of neurovascular and lymphatic vessels and the direction of branching and adjacency, and to recognize various structures, so that the structures that do not need to be displayed can be cut off at any time, and the parts that need to be observed can be fully revealed. It is important not to cut blindly and indiscriminately, wasting cadavers and time and failing to achieve the purpose of dissection.
2. Protect the body moist part of the dissection has not yet been (such as hands, feet, face, scalp and external genitalia, etc.) should pay attention to the protection, should be covered with a wet cloth, so as not to dry and not easy to dissect. Has been dissected part of the skin to be covered and tied or sewn with rope, thread, and then wrapped with a wet cloth to keep the specimen moist.
3. Prevent hand trauma during dissection operators need to cut the nails short and operate in strict accordance with the operating procedures and methods to prevent hand trauma. If there is trauma to the hand, the dissection operation should be stopped immediately.
Third, the general method of dissection
1. Skin removal When making skin incision, in order to prevent the incision from being skewed, the back of the knife can be used to cut a trace on the skin, and then cut along the trace. Longer incisions are made with the bow-tie method, while shorter incisions are made with the pen-tie method. The tip of the knife starts to cut at right angles to the skin. When the tip of the knife cuts into the fascia (sensing a sudden decrease in resistance), the blade is tilted at a 45-degree angle to the skin surface, and the back of the knife is cut to the end with the pressure of the index finger, then the blade is lifted up at right angles to the skin surface, and finally the knife is removed. The skin incision requires neat edges and uniform depth. Hold the corner of the skin to be removed with toothed forceps or skin forceps, and use the knife to separate the superficial fascia from the skin. When the skin is separated to a certain extent, the skin can be lifted tightly with the left thumb and signet finger (because the anatomical forceps cannot hold large pieces of skin). As the knife blade continues to peel away the skin at the junction of the skin and the superficial fascia, the knife blade should be biased to the side of the skin to keep the superficial fascia off the skin as much as possible, so as to avoid damaging structures such as cutaneous nerves and subcutaneous blood vessels in the superficial fascia.
2. Repair and cleaning of superficial structures There are nerves, blood vessels and lymph nodes in the superficial fascia. Before removing the superficial fascia, first identify the major cutaneous nerves, blood vessels and lymph nodes in it. Dissection of superficial nerves and blood vessels can be traced by both the retrograde and retrograde methods of repair and cleaning. Proximal method: If looking for a cutaneous nerve, first find the small trunk where it exits the deep fascia, and then follow this towards the end. Retrograde method: first find a terminal small branch of the superficial nerve, and then from small to large, from shallow to deep to trace the whole branch to repair clean. Small subcutaneous arteries and superficial veins can also be visualized and cleaned by either the retrograde or retrograde method. Lymph nodes can be found in the superficial fascia, lifted with a phalanx, and peeled off with the tip of a knife or fine-tipped forceps in a radial direction in all directions, so that some of the incoming and outgoing lymphatic vessels can be clearly visualized, and then trimmed with ophthalmic scissors. Once these structures have been located, the superficial fascia can be removed. The method of removal is to make an incision in the superficial fascia and lift it up, separate the superficial fascia from the deep fascia with a knife (with the blade of the knife biased toward the deep fascia), and gradually remove the superficial fascia to expose the deep fascia.
3. Muscle, tendon and ligament repair and cleaning Separation of the muscles can be used to blunt separation of the anatomical method. For example, with a knife handle, blunt forceps or fingers, etc. into the muscle gap and separate the muscle, repair and clean the muscle, appropriate muscle tension, with forceps to lift the muscle surface of the fascia, the direction of the knife blade should be perpendicular to the direction of the muscle fibers, so as not to blade with the connective tissue compartment deep into the muscle fibers between the muscle fibers and damage to the muscle fibers. Tendons and ligaments should be cleaned in the direction of the fibers, some joint capsule ligaments, the outline of the fiber direction is not clear enough, can be used in the direction of the fibers with a coarse cloth to wipe hard to fill the connective tissue between the fibers to wipe away, and then put into the water with a curved scissors to carefully cut off the floating tissue, you can see the fibers and their direction. Tendon fiber bundle dissection, can first be soaked in 25% acetic acid solution for about 24 h, so that the expansion of the softening, and then separated with forceps, can clearly show the arrangement and direction of the tendon fiber bundle.
4. Deep blood vessels and nerves of the extremities of the deep blood vessels, nerves are located in the deep surface of the muscle or between the muscle and the muscle, they are mostly surrounded by connective tissue to form a vascular nerve bundle. Anatomy should be used first blunt separation method to expose the surface of the vascular nerve bundle, and then use the knife blade to gradually repair the connective tissue encircling. The repair and cleaning of blood vessels and nerves can be carried out by transporting the knife along the long axis of the vascular nerve trunk, from the trunk to the end. If there are more veins, in order to make the important part of the specimen to show clearly, can remove the small and leave the big. Thoracic and abdominal blood vessels are located in the deep surface of the thoracic and peritoneal membranes or between the two layers of the folds of the thoracic and peritoneal membranes, and when cleaning, the thoracic and peritoneal membranes are torn off and separated with forceps, and then connective tissue is removed.
5. Body organs The key area for anatomical exposure of the substantial organs in the body is the "door" of the organs, and when repairing and cleaning, attention should be paid to carefully removing the fat and connective tissues, and preserving the various ducts entering and exiting the "door" as well as their positional relationship with each other. When exposing the internal structure of a substantial organ, the dissection is usually started from the area of the "door" to the deeper part, or separated and dissected along the travel of the main internal ducts. In the preparation of specimens of cavitary organs, care should be taken to select material that is in a moderately filled state and has a more typical appearance.