Back Muscles

Splenius

This muscle is located on the back of the neck. It lies deep to the rhomboideus capitus and rhomboideus cervicus muscles. This muscle extends the head and flexes it to the side. To isolate it you must move the rhomboideus capitus and rhomboideus cervicus to the side using the blunt probe and it will be underneath.

Trapezius

 The trapezius is a broad dorsal muscle that lies on the surface. It is posterior to the brachiocephalic muscle and dorsal to the deltoid muscle. This muscle retracts the scapula during forelimb movement.

Rhomboideus Cervicus

 The rhomboideus cervicus is the middle of the three rhomboid muscles. It originates from the cervical vertebrae. To isolate this muscle you must use the blunt probe to detach the skin from the muscle and then separate the muscle from the surrounding muscles.

Rhomboideus Capitus

The rhomboideus capitus is the most anterior of the three muscles. It goes from the occipital part of the cranium to the vertebrae border. This muscle draws the scapula forward. To isolate this muscle you must use the blunt probe to detach the skin from the muscle and then use it to separate it from the rhomboideus cervicus. Also make sure you remove any connective tissue.

Lateral Leg Muscles

Biceps Femoris

The biceps femoris is the largest muscle of the thigh and covers most of its surface. To isolate you must remove the connective tissue from above and below the muscle so that you can insert the blunt probe underneath the muscle.

Gluteus Medius

The gluteus medius lies deep to the gluteus maximus and the tensor fascia lata. This muscle acts to extend the hip and abduct the thigh.

Rectus Femoris

The rectus femoris is mostly covered by the tensor fascia lata. It is the most anterior muscle of the quadriceps. It is thick and on the anterior side of the thigh. To isolate this you must dig under the tensor fascia lata and remove the connective tissue and fat with the blunt probe.

Vastus Lateralis

The vastus lateralis is seen on the lateral side of the hind leg. It also is covered by the tensor fascia lata so removal of the tensor fascia lata is required before isolation. It must be then separated from the rectus femoris by using the blunt probe to find a weak point between the two; then separate them.

Tensor Fascia Lata

The tensor fascia lata is a tensing muscle that pulls the fascia lata, which is a sheet that lies along the knee and inserts over the tibia. It flexes the hip or extends the knee. To isolate this you must remove the connective tissue and fat. The vastus lateralis and rectus femoris lie beneath.

Semitendinosus

The semitendinosus lies medial to the biceps femoris. It inserts into the tibia and the calcaneous. To isolate this muscle you must use your blunt probe to remove connective tissue and any fat. Then you must find the weak spot to isolate the muscle from the semimembranosus.

Semimembranosus

The semimembranosus lies posterior and medial to the semitendinosus.You must first remove the gracilis to uncover this muscle. Then use the blunt probe to remove any other connective tissue and  to separate it from the semitendinosus.

Medial Hind Leg Muscles

The Gracilis is a thin muscle on the posterior medial side of the hind limb. This muscle adducts the hind limb. It must be removed from the leg to reach the muscles beneath. To do this you must rip it off of the hind leg by removing the connective tissue fibers.

Gracilis

Tibialis Anterior

The tibialis anterior lies upon the tibia. This muscle flexes the ankle. To isolate it you must use the blunt probe to remove the connective tissue and fat. You will then be able to lift it up with the probe.

Gastrocnemius

The gastrocnemius originates at the femur and goes to the calcaneous bone of the ankle. It extends the muscle and flexes the knee. To isolate it you must break the connective tissue and remove the fat with the blunt probe.

Soleus

This muscle is found close to the gastrocnemius. Use the blunt probe to separate the soleus from the gastrocnemius muscle and the tibia bone. This muscle extends the ankle and is known as a plantar flexion.

Extensor Digitorum Longus

The extensor digitorum longus is shaped as a thin muscle and its end is a long tendon. It connects to the digits. Its function is to extend the big toe and assists in the dorisflexion of the foot at the ankle. To isolate use the blunt probe to remove connective tissue and separate it from the tibialis anterior.

Vastus Medialis

  The vastus medialis is caudal to the rectus femoris on the medial side of the hind leg. It extends from the femor. Use the blunt probe to find the separation between the rectus femoris and this muscle.

Saritorius

The saritorius is located anterior to the adductor magnus. It is thin and triangular coming from the iliac fascia. It flexes the hip and adducts the thigh. To isolate this you must use the blunt probe to remove connective tissue and fat to then separate this muscle from the others.

Adductor Magnus

The adductor magnus is a triangular muscle that originates from the pubis and inserts into the femur along the medial side. This muscle acts to adduct the thigh. Use the blunt probe to find a weak point to separate this from the semimembranosus.

Peroneous Tertius

Peroneous Longus

These two deeper muscles of the lower hind leg act to move the ankle. They originate from the tibia and go to the femur. To isolate use the blunt probe to separate them from each other and the surrounding muscles.

Neck and Throat Muscles

Sternomastoideus

This muscle originates from the sternum and splits into a 'V" shape. This muscle flexes the head to the chest and inclines it to one side or the other. To isolate it dig through the connective tissue and split through the mid line of the neck. Using the blunt probe separate the two outermost muscles and separate them from the others.

Sternohyoideus

  The sternohyoideus depresses the hyoid bone and helps with speech and swallowing. This is the most superficial muscle of the neck. It is off to the side of the sternomastoideus. To isolate it use the blunt probe to remove any connective tissue and bring the muscle upwards with the probe.

Sternothyroideus

The sternothyroideus lies beneath the sternohyoideus muscle. You must separate the right and left side of the sternohyoideus to reveal this muscle. This muscle depresses the larynx and is involved in speech and swallowing.

Masseter

The masseter muscle is a thick muscle that has two parts on either side of the neck. It lies directly beneath the skin. Using the blunt probe you must remove the connective tissue. It is used to chew and grind food substances.

Brachiocephalic

The brachiocephalic muscle is large and originates from the back of the head and neck to the shoulder. It moves the forelimb anteriorly. To isolate this you must use the blunt probe to remove any connective tissue and fat.

Lateral Forelimb Muscles

Deltoid

The deltoid is not fully developed in fetal pigs. It is an elongated, thin muscle extending the anterior surface of the shoulder of the forelimb. This muscle raises the humerus.Using the blunt probe, you must remove all the fat and connective tissue from this area before you can fully isolate this muscle.





The following pictures are the extensors of the wrist and digits found on the lateral side of the forearm.

Antebrachial Fascia

Brachioradialis

The brachioradialis assists in flexing the elbow.







The picture to the left shows the other four extensors of the wrist and digits. Starting from the far left they are: extensor carpi radialis, extensor digitorum communis, extensor digitorum lateralis, and extensor carpi ulnaris.

Biceps Brachii

The biceps brachii lies just medial to the brachiocephalic and the pectoralis muscles. It comes from the scapula and inserts on the proximal ends if the radius and the ulna. This muscle flexes the lower forearm. To isolate this muscle you must use the blunt probe to remove any connective tissue form the area. Then use the probe to separate the biceps brachii muscle from the surrounding muscles.

Triceps Brachii

The triceps muscle consists of the triceps brachii medial head and the triceps brachii long head. You must use your blunt probe to remove any connective tissue and fat from the area and then separate both muscles from each other. This muscle extends the elbow.

Ventral Muscles

Pectoralis Major

This muscle is located in between the sternum and the front leg. It is used to move the foreleg towards the chest. To isolate this muscle you must first break off the connective tissue above the muscle with your blunt probe. Also remove the connective tissue from underneath the muscle so you can use your blunt probe to lift up the pectoralis major. 

Latissimus Dorsi

This muscle is below the pectorialis major. This muscle moves the foreleg dorsally and caudally. You must use your blunt probe to remove the connective tissue from the top of this muscle in order to isolate it. The fibers of this muscle run anterior direction, opposite those of the pectoralis major. You have to lift up the arm of the pig to isolate it.

Step 1: Skinning

You will need a dissection pan, scissors, blunt probe, and goggles. Place the pig in the pan ventral surface upward. To begin skin only the right side of the pig. Make a small incision with your scissors around the umbilical cord being sure not to cut too deep. Continue to cut along the mid line, towards the head, in a straight line until you reach the anterior end of the neck. Using the blunt probe (picture in the center above) detach the skin from the muscle up to the spine. Then cut up the leg and around the ankle in a circle so the skin can be removed using the blunt probe technique used for the back. Also cut up the arm and around the wrist and use the blunt probe to detach the skin from the muscle. Skin both sides of the neck, but do not get into the cheek area. Use your blunt probe to separate the two sternohyoid muscles, the two muscles at the mid line of the neck. Be sure to keep the skin still attached to the back to be used after skinning to withhold the moisture .