Lab Handout #4 East Los Angeles College

Transcription

1 Cat dissection Introduction: The skeletal muscles of all mammals are named in a similar fashion. Some muscles that are separated in animals are fused in humans and some muscles present in animals are absent in humans. This exercise involves dissection of the cat musculature to improve your knowledge of the human muscular system. The following are the steps to the proper and orderly preparation and skinning of the cat to optimize its use for dissection throughout the rest of the semester. At the conclusion of this and each dissection, thorough cleansing of instruments, desks, sinks and floors is extremely important. Please be rigorous in your cleanliness. Use a sponge for all steps of cleansing except the very last. Use a single paper towel to finish drying the cleansed desk. 1. LABEL BAG 2. Do not dispose of this fluid when you remove the cat; the fluid prevents the cat from drying out: At the sink, with rubber gloves, carefully cut open plastic bag. Remove cat tail first into the sink so that excess preservative fluid remains in the bag. Squeeze out excess fluid from the cat's fur by milking down from head to tail. Set aside the bag with the cat juice so to keep the cat muscle moist for later use. Preparing for the cat dissection: Incisions to be made in skinning a cat. 1. Place the cat ventral side down on the dissecting tray. 2. With a scalpel, make a short, shallow incision in the midline of the neck just to penetrate the skin 3. From this point on, use scissors & continue the cut from the length of the back to the sacrolumbar region, stopping at the tail 4. From the dorsal surface of the tail region, continue the incision around the tail, encircling the anus and genital organs. The skin will not be removed from this region. 5. Beginning again at the dorsal tail region, make an incision through the skin down each hind leg nearly to the ankle. Continue the cuts completely around the ankles 6. Return to the neck. Cut the skin around the neck. 7. Cut down each foreleg to the wrist. Completely cut through the skin around the wrists. 8. Now free the skin from the superficial fascia that binds it to the underlying structure. With one hand, grasp the skin on one side of the midline dorsal incision. Then, using your fingers or a blunt probe. Brea, through the "cottony" CT fibers to release the skin from the muscle beneath. Work toward the ventral surface and then toward the neck 1 P age

2 2 P age

3 Muscle Dissection 1. Listed below are the major muscles that you need to identify from your cats. For you dissection, you will need to remove any excess fat and fascia that may cover the muscles. Be careful as you remove these connective tissues-you do not need to remove muscle tissue during this process. Muscles are extremely thin, so be careful as you remove fat and fascia from the cat. As you work on the cat, try to separate the muscles along their natural lines. Do not cut or remove any muscles. Be able to identify by sight, all of the muscles listed on this sheet. 2. Useful Website Cat Muscle Dissection and Identification Chest Muscles Muscles of Abdominal Wall Superficial Back Muscles Muscle of the shoulder Muscles of the brachium Superficial 1. xiphihumeralis 2. pectoralis major 3. pectoralis minor 4. pectoantebrachialis Deep 5. serratus ventralis 6. anterior scalenus 7. middle scalenus 8. posterior scalenus 1. EXTERNAL OBLIQUE 2. INTERNAL OBLIQUE 3. TRANSVERSUS ABDOMINIS 4. RECTUS ABDOMINIS 1. Spinotrapezius 2. Acromiotrapezius 3. Clavotrapezius 4. Spinodeltoid 5. Acromiodeltoid 6. Clavodeltoid (clavobrachialis) 7. latissimus dorsi 1. supraspinatus 2. infraspinatus 3. teres minor 4. subscapularis 5. levator scapulae ventralis 6. teres major 7. rhomboids 8. rhomboid capitis 9. splenius 1. biceps brachii 2. brachialis 3. triceps brachii (long head) 4. triceps brachii (medial head) 5. triceps brachii ((lateral head) 6. epitrochlearis 3 P age

4 Muscles of antebrachium & Manus Muscles of the Hip Muscles of Thigh (hindlimb) Muscles of the shank (leg) 1. brachioradialis 2. extensor carpi radialis longus & brevis 3. extensor digitorum communis 4. extensor digitorum lateralis 5. extensor carpi ulnaris 6. pronator teres 7. flexor carpi radialis 8. palmaris longus 9. flexor carpi ulnaris 1. gluteus medius 2. gluteus maximus 3. caudofemoralis 1. sartorius 2. gracillis 3. tensor fascia lata 4. fascia lata (iliotibial band) 5. quadriceps femoris vastus lateralis vastus medialis vastus intermedius rectus femoris 6. Hamstrings a. biceps femoris b. semitendinosus c. semimembranous 7. Iliopsoas 8. Pectineus 9. adductor femoris 10. adductor longus 1. gastrocnemius 2. soleus 3. plantaris 4. calcaneal (Achilles ) tendon 5. fibularis (peroneus) 6. tibialis anterior 7. extensor digitorum longus 8. flexor digitorum longus 4 P age

5 Major differences between Human & Cat Muscles pectoralis major pectoralis minor pectoantebrachialis Xiphihumeralis clavotrapezius, acromiotrapezius, spinotrapezius caudofemoralis gluteus maximus sartorius adductor femoris (cat) epitrochlearis larger in human, smaller in cat smaller in human, larger in cat three muscles in cat, one muscle in human (trapezius) larger than gluteus medius in humans, smaller than gluteus medius in cat wide muscle in cat, narrow muscle in human adductor magnus (human) 5 P age