Cat Dissection Handbook
Mrs. Connell
Anatomy I H
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Table of Contents
Safety Procedures………………...………………………………..…….3
Preparing the Cat………………………...………………………….....…4
Removing the Skin……………………………...……………………......5
Opening Ventral Body Cavities…………………...………………...6
Skeletal Muscles……………………………………………...…………...7
Head & Neck……………………………………………...……...7
Chest & Abdomen…………………………………………......7-8
Back & Shoulder……...…………………………………..……8
Arms……………………………...…………………………….…...9
Legs……………………………………..………………………......10
Plexuses & Major Nerves………………………..……………………11
Brachial Plexus…………………………………..……………..11
Lumbosacral Plexus…………………………………..……...11
Circulatory System & Blood Vessels……………………………..12-14
Endocrine System……………………………………………………..…15
Respiratory System……………………………………………………..16
Digestive System…………………………………………………………17
Urinary & Reproductive Systems………………………………….18
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Safety Procedures
1) Do not engage in horseplay! Common sense should rule here
when working with sharp instruments.
2) Pin the specimen to be dissected securely in the dissecting pan or
tray. Never dissect while holding the specimen in your hand(s).
3) Wear safety goggles and gloves at all times, even if you are not
doing the dissecting.
4) You must wear closed toed shoes and pull long hair out of your
face.
5) Point sharp objects or tools away from yourself and others.
6) Wash and return your dissection tools to their appropriate
container.
7) Care for and dispose of your dissection in accordance with the
directions given by your instructor.
8) Obviously one should not eat or drink in a laboratory where a
dissection is occurring.
9) Wash your hands and dissection area after each dissection.
10) Minimize the number of cats sacrificed for dissection.
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Preparing the Cat
1. Remove cat from bag.
2. Lay cat on dissecting tray.
3. Keep liquid preservatives in the bag to keep cat moist for
future use.
4. Place cat ventral surface up on dissecting tray.
5. Identify the gender of your cat.
a. Males: Scrotum & prepuce
b. Females: urogenital aperture
6. Prepare a label for your cat bag.
a. Name of group
b. Name of cat
Mrs. Connell’s Favorite Team
Mr. Billingsworth
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Removing the Skin
1. Pinch skin on ventral surface of neck. Use scissors to make a
small incision at the midline through the skin ONLY. DO NOT
cut into the muscle layer.
2. Cut longitudinally along the midline incision toward the
lower lip and in the opposite direction all the way to the
genital area.
3. Cut skin around the neck.
4. Cut horizontally across the chest and diagonally across the
groin, and continue cutting down the midline of the
extremeties. Cut the skin around each paw.
5. Use your fingers to peel the skin away from the underlying
muscles until it is only attached at the face and the tail.
6. Skin should be left on the base of the tail, the face, ears,
forehead, and feet.
7. Carefully remove as much fat and superficial fascia as
possible with fingers or forceps.
8. Dispose of skin as specified by instructor.
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Opening Ventral Body Cavities
1. At midline above the pubic bone, carefully make a
longitudinal incision through the abdominal muscles and
continue this incision to the ribs.
2. Cut either to the right or left of the sternum, cutting through
the costal cartilages all the way to the neck.
3. Cut horizontally along this incision at the base of the neck.
4. Cut horizontally anterior and posterior to the diaphragm and
cut the diaphragm away from ventral body wall. Open these
flaps to expose the body cavities while leaving the diaphragm
intact.
5. Use scalpel to cut longitudinally down the inner wall of the
rib cage. Carefully bend the walls outward to break the ribs,
allowing the thoracic flaps to stay open.
6. Dispose of fat as specified by instructor.
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Skeletal Muscles
1. Carefully remove fascia to observe specific muscles.
2. Scissors or scalpels can cut the muscles or other structures.
3. Use blunt dissection: using blunt probes and forceps to
separate muscles.
4. To observe deep muscles, it will be necessary to cut at the
superficial muscle at the midline and pull back the edges
toward the origin and insertion.
Head & Neck Muscles
 Masseter
 Digastric
 Mylohyoid
 Sternohyoid
 Sternothyroid
 Sternomastoid (analogous to sternocleidomastoid)
Muscles of the Chest
 Pectoantebrachialis (not in humans)
 Pectoralis major
 Pectoralis minor
 Xiphihumeralis (not in humans)
5. Cut and pull back pectoralis major, pectoralis minor, and
xiphihumeralis to find the following deep muscles of the
chest:


External intercostals
Serratus ventralis (analogous to serratus anterior)
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Muscles of the Abdomen
 Rectus abdominis
 External oblique
6. Cut and pull back the thin external oblique:

Internal oblique
7. Cut and pull back the thin internal oblique:

Transverse abdominis (sometimes attached to the
underside of the internal oblique)
Muscles of the Back & Shoulder
 Trapezius muscles
o Clavotrapezius
o Acromiotrapezius
o Spinotrapezius
 Deltoid muscles
o Clavobrachialis
o Acromiodeltoid
o Spinodeltoid
 Latissimus dorsi
8. Cut and pull back the trapezius muscles and latissimus dorsi
to observe the deep muscles







Splenius
Levator scapulae ventralis (analogous to levator
scapulae)
Rhomboideus capitis (not in humans)
Rhomboideus (major and minor in humans)
Supraspinatus
Infraspinatus
Teres major
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Muscles of the Arms
 Brachialis
 Triceps brachii lateral head
 Triceps brachii long head
 Biceps brachii
9. Cut and pull back lateral head of triceps brachii:

Triceps brachii medial head
Muscles of the Forearm
 Brachioradialis
 Extensor carpi radialis longus
 Extensor digitorum communis
 Extensor digitorum lateralis
 Extensor carpi ulnaris
 Flexor carpi radialis
 Palmaris longus
 Flexor carpi ulnaris
 Pronator teres
10. Lift extensor carpi radialis longus:

Extensor carpi radialis brevis
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Muscles of the Thigh
 Sartorius
 Tensor fasciae latae
 Gluteus medius
 Gluteus maximum
 Caudofemoralis
 Vastus lateralis
 Biceps femoris
 Semitendinosus
 Adductors
 Gracilis
11. Cut and pull back Sartorius and the gracilis muscles:








Iliopsoas
Pectineus
Adductor longus
Adductor femoris (analogous to adductor magnus)
Vastus lateralis
Rectus femoris
Vastus medialis
Semimembranosous
Muscles of the Leg
 Gastrocnemius
 Soleus
 Peroneus
 Extensor digitorum longus
 Tibialis anterior
 Flexor digitorum
 Gastrocnemius
o Attached to Calcaneal tendon
 Connects to calcaneal bone
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Plexuses & Major Nerves
Brachial Plexus
1. Place cat dorsal side down.
2. Cut through the middle of the pectoralis major and minor
muscles if not already done during the observations of the
skeletal muscles and pull these muscles back.
3. The brachial plexus should be exposed. Use blunt dissection
to separate these nerves.




Musculocutaneous Nerve
o Innervates coracobrachialis
o Innervates biceps brachii
Radial Nerve
o Largest
o Innervates heads of triceps
o Innervates forearm muscles
Median Nerve
o Follows similar pathway as brachial artery
o Innervates forearm muscles
Ulnar Nerve
o Innervates forearm muscles & front paws
Lumbosacral Plexus
4. Go to lumbar area. Find psoas major muscle and attached is:

Femoral Nerve
5. Place cat dorsal side up.
6. Cut through the middle of the biceps femoris muscle and pull
back to find the:

Sciatic Nerve
7. Follow the course of the sciatic nerve down the posterior
thigh which will divide into two separate nerves:


Tibial Nerve
Common Fibular (peroneal) Nerve
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Circulatory System & Blood Vessels
The cats are injected with dyes to identify the arteries and veins.
Arteries are injected with red latex and veins with blue latex.
1. Place cat ventral side up.
2. Use blunt dissection to discard the fasica that protects and
secures the blood vessels.
3. Identify these major organs for relationship:
Major Organs
 Heart
 Trachea
 Lungs
 Diaphragm
 Stomach
 Spleen
 Pancreas
 Liver
 Small intestine
 Large intestine
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4. Use scissors to cut the pericardial sac surrounding the heart
to expose the organ. Identify the following arteries:
Arteries (above the diaphragm)
 Pulmonary trunk
 Right pulmonary artery
 Left pulmonary artery
 Ascending aorta
 Aortic arch
o Brachiocephalic artery
 Right subclavian artery
 Right common carotid
 Left common carotid
o Left subclavian artery
 Vertebral artery
 Axillary artery
 Brachial artery
 Radial artery
 Ulnar artery
 Thoracic aorta
 Abdominal aorta
Arteries (below the diaphragm)
 Celiac trunk
 Superior mesenteric artery
 Renal arteries
 Testicular arteries (males)
 Ovarian arteries (females)
 Inferior mesenteric artery
 Iliolumbar arteries
 Right & Left external iliac arteries
 Internal iliac artery
 Femoral artery
 Popliteal artery
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Veins (below the diaphragm)
 Great saphenous vein
 Femoral vein
 External iliac vein
 Common iliac vein
 Inferior vena cava
 Renal veins
 Gonadal veins
 Hepatic portal vein (might not be blue, might be brown)
Veins (above the diaphragm)
 Radial vein
 Ulnar vein
 Brachial vein
 Axillary vein
 Subclavian vein
 Right/Left brachiocephalic vein
 Superior vena cava
 External jugular vein
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Endocrine Organs & Lymphatic System
1. Place cat ventral side up
Thoracic Cavity
 Thyroid gland
 Thymus
 Thoracic duct
Abdominal Cavity
 Pancreas
 Adrenal glands
 Gonads (ovaries or testes)
 Spleen
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Respiratory System
Major Organs
 Larynx
 Trachea
 Lungs
 Diaphragm
Respiratory Structures
 External nares
 Nasal cavity
 Oral pharynx
 Larynx
 Thyroid cartilage
 Cricoid cartilage
 C-shaped tracheal cartilages
 Trachealis muscle
 Right/Left Primary bronchi
 Secondary bronchi
 Tertiary bronchi
 Upper, middle, lower lobes of lungs (right lung has four
lobes)
 Pulmonary artery
 Pulmonary vein
 Parietal pleura
 Visceral pleura
 Diaphragm
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Digestive System
Esophagus & Abdominal Organs
 Laryngopharynx
 Esophagus
 Diaphragm
 Esophageal hiatus
 Peritoneum
 Liver
 Gallbladder
 Cystic duct
 Falciform ligament
 Stomach
o Esophageal sphincter
o Cardia
o Fundus
o Body
o Pylorus
 Pancreas
 Common bile duct
 Common hepatic duct
 Small intestine
o Duodenum
o Jejunum
o Ileum
o Ileocecal junction/sphincter
 Large intestine
o Colon
o Cecum
o Ascending colon
o Transverse colon
o Descending colon
o Rectum
o Anus
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Urinary System & Reproductive Systems
1. Pull back the abdominal viscera from the digestive system.
Kidney
 Renal hilus
 Renal artery
 Renal vein
 Ureter
Urinary Bladder
 Urethra
Male Reproductive System
 External urethral orifice
 Penis
 Prepuce
 Epididymis
 Vas deferens
 Inguinal canal
 Prostate
Female Reproductive System
 Body of uterus
 Uterine horns
 Ovaries
 Uterine tubes
 Fimbriae
 Urethra
 Vagina
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