Muscle Lab 4
Muscles of the Lower Extremity
In this lab you will learn about some of the muscles of the leg and pelvis by locating them on the dissector body and partially constructing a leg.
Begin by clicking on the following to orient the body:
Locate the following muscles:
Sartorius
Rectus Femorus
Vastus Medialis
Vastus Lateralis
Adductor Longus
Gracilis
The rectus femorus, vastus medialis and vastus lateralis make up 3 of the 4 quadriceps muscles. These work to extend the knee joint.
To find the 4th quadriceps muscle, dissect away the rectus femorus right by clicking on it.
Just deep to the rectus femorus you will find the vastus intermedius. This is the 4th quadriceps muscle.
Dissect away the sartorius muscle right. In the upper part of the leg locate the iliacus muscle right. This muscle along with the psoas muscle which is very deep form the iliopsoas muscle.
Now using the thumbwheel, rotate the body 90 degrees to the right.
Locate the following:
Iliotibial Tract right--this is a long band of connective tissue known as an aponeurosis. This tissue acts like a flat tendon. Since it is a tendon it can develop tendonitis. This is called iliotibial band syndrome.
Muscle of the gluteus medius right--this is part of the gluteal group of muscles. There are 3 gluteal muscles--the maximus, medius and minimus. The gluteus medius is a common site for intramuscular injections.
Muscle of the gluteus maximus right--the largest of the gluteal muscles. It works to extend the hip.
Dissect away the iliotibial tract right. Locate the gluteus medius again. Notice how far under the iliotibial tract it runs.
Locate the muscle of the tensor fascia latae right. This muscle attaches to the iliotibial band and works to produce hip abduction.
Rotate the body to 180 degrees using the thumbwheel.
You should now see a posterior projection.
Locate the following:
Long head of the biceps femorus right
Muscle of the semitendonosus right
Muscle of the semimembranosus right
Muscle of the gracilis right
The biceps femorus, semitendonosus and semimembranosus make up the hamstring group.
Dissect away the muscle of the gluteus maximus right and muscle of the gluteus medius right.
Deep to the gluteus medius you should be able to find the 3rd gluteal muscle the gluteus minimus.
Locate the muscle of the piriformis right. Also locate the sciatic nerve right. Notice how close the piriformis muscle is to the sciatic nerve. In some cases a tight piriformis muscle can irritate the sciatic nerve. This is called piriformis syndrome.
Dissect away the muscle of the semitendonosus right and muscle of the semimembranosus right.
Locate the muscle of the adductor magnus right. The adductor magnus along with the adductor longus and gracilis work to adduct the hip.
Muscles of the Lower Leg
Reorient the body by clicking on the following:
Locate the following:
Osseous part of the tibia right
Muscle of the tibialis anterior right
Medial head of the gastrocnemius right
Muscle of the soleus right
Notice how the tibialis anterior is just lateral to the tibia. This muscle is a common site for shin splints.
Using the thumbwheel, rotate the body 90 degrees to the right.
Locate the muscle of the fibularis right. This muscle is also called the peroneus longus. It is part of a group of 3 muscles.
Rotate the body to 180 degrees.
Locate the medial and lateral heads of the gastrocnemius right. Locate the calcaneal tendon right. Notice how the 2 heads of the gastrocnemius form a common tendon. The calcaneal tendon is also known as the achilles tendon.
Dissect away the medial and lateral heads of the gastrocnemius right. Deep to the gastrocnemius you will find the soleus.
Upper Leg Construction
Reorient the body by clicking on the following:
Anterior Lower Extremity Skeleton
Notice how the blue transverse plane is located near the hip joint. You can move the plane by clicking and dragging it. For now, just leave it in this position.
On the screen below you will see a transverse projection of the anatomy. This picture corresponds to the plane.
On the screen below locate and click on the following structures:
Muscle of the rectus femorus right
Muscle of the tensor fascia latae right
Muscle of the gluteus maximus right
Muscle of the glutues medius right
Vastus lateralis right
Click and drag the blue plane so it is about midway down the femur.
On the screen below locate and click on the following:
Vastus medialis right
Vastus intermedius right
Muscle of the adductor longus right
Muscle of the adductor magnus right
Using the thumbwheel, rotate the body 180 degrees. You should now see the posterior leg.
On the screen below locate and click on the following:
Muscle of the semimembranosus right
Muscle of the semitendinosus right
Long head of the biceps femorus right
You have now constructed the upper leg. Use the thumbwheel to explore your creation.
Lower Leg Construction
Using the thumbwheel reorient the body by rotating back to 0 degrees.
Click and drag the blue plane down to about midway down the tibia.
Locate and click on the following on the screen below:
Muscle of the tibialis anterior right
Muscle of the fibularis muscles right
Muscle of the soleus right
Medial head of the gastrocnemius right
Lateral head of the gastrocnemius right
Use the thumbwheel to explore your creation.
This concludes the lab.