Muscle Lab 1
In this lab you will be learning the locations of a number of muscles. This will be done by using the dissector software to insert muscles over the skeleton and dissect away the superficial structures to get to some of the muscles. This should give you a good look at the structure of the muscular system.
Begin by clicking on the following to orient the image:
Dissect away the following structures by clicking on them:
Skin
Fatty layer of the subcutaneous tissue
Veins of the anterior head and neck
Highlight and locate the following facial muscles:
Orbicularis oculi (orbital part of orbicularis oculi)
Orbicularis oris
Dissect away both right and left platysma muscles.
Locate the right and left sternocleidomastoid muscles (sternal head of the sternocleidomastoid).
Locate the right and left trapezius muscles (superior part of trapezius).
Locate the deltoid muscles (clavicular and sternal parts).
Moving more inferior locate the pectoralis major muscles. These have both sternal and clavicular divisions.
Abdominal Muscles
There are 4 abdominal muscles in 3 layers. The superficial muscles are the rectus abdominus commonly called the 6-pack and the external oblique. The next layer consists of the internal obliques and the deepest layer consists of the transversus abdominus.
Click on the following to orient the body:
Moving more inferior locate the linea alba.
Locate the right and left external oblique muscles. Using the thumbwheel rotate the body 90 degrees to the right. Observe the posterior attachments of the external oblique muscle. Notice how the fibers angle downward from the back to the front.
Rotate the body back to 0 degrees.
To see the rectus abdominus you will need to dissect off some connective tissue.
Dissect away the following:
Linea Alba
Aponeurosis of the external oblique left
Aponeurosis of the external oblique right
Anterior midline of extraperitoneal fat
Aponeurosis of internal oblique left
Aponeurosis of internal oblique right
You should now be able to view the right and left rectus abdominus muscles.
Dissect away the right and left external oblique muscles.
You should now be able to see the right and left internal oblique muscles.
Rotate the body 90 degrees to the right.
Observe the posterior connection points for the internal oblique.
Notice how the fibers angle downward from front to back (opposite of the external oblique).
Rotate the body back to 0 degrees.
Dissect away both right and left rectus abdominus muscles as well as the right and left obliques.
You should now be able to see the right and left transversus abdominus muscles.
Rotate the body 90 degrees to the right.
Notice how the fibers of the transversus abdominus run almost parallel to the transverse plane.
This concludes the lab.