Skeletal System Overview:
The Skeletal System is the "backbone" of the cat (literally). It is responsible for it's structure, as well as protecting many vital organs. Bones that are imperative to the structure of the cat are mostly in its limbs, while the spine is the most important bone required for structure. The spine with its 27 vertebrae on top of the sacrum (not including the vertebrae in the tail) technically is needed for both structural support and organ protection, as it encapsules the spinal cord which if severed can result in paralysis or death depending on where it was severed. Other structural bones include the Tibia, Fibula, Femur, Humerus, Os Coxae, Clavicle, and the Scapula. All of these bones are vital in giving the cats body its shape and support. As for bones used in protection, they come few and far between. As we have already mentioned, the Spine is used in protecting the Spinal Cord. The vital organs of the torso (Heart and Lungs) are protected by the Ribs which are attached to the Sternum via Costal Cartilage. The Brain is protected by the Cranium
Bones of Upper Extremities:
1: Scapula; To provide movement and stabilization for the arm
3: Ulna; Connector for the many forearm muscles, and needed in order to pronate and supinate the forearm
4: Radius; Connector for the many forearm muscles and needed in order to pronate and supinate the forearm.
- 1a: Supraspinous fossa; Connector for the Supraspinatous muscle
- 1b: Infraspinous fossa; Connector for the Infraspinatous muscle and for the Teres Major and Teres Minor at its border
3: Ulna; Connector for the many forearm muscles, and needed in order to pronate and supinate the forearm
4: Radius; Connector for the many forearm muscles and needed in order to pronate and supinate the forearm.
Bones of Lower Extremities:
1: Femur; Imperative to structural support, as it is the largest bone in the body. It is also a large site for muscle connection; Gluteus Maximus, Gluteus Minimus, Vastus Medialis, Lateralis, and Intermedialis, etc.
3: Fibula; Stabilizing the ankle and supporting muscles going to the foot
- 1a: Femoral Condyles; Connection sites for many ligaments in the knee joint
3: Fibula; Stabilizing the ankle and supporting muscles going to the foot
Bones Dorsally (Spine)
1: Cervical Vertebrae (7); Used in support like most vertebrae, but is especially important to supporting the head. Also houses the Spinal Cord, and it is typically fatal if a cervical vertebrae breaks.
2: Thoracic Vertebrae (13); Holds the rib cage, protects heart and lungs dorsally. Also holds the spinal cord, and a fracture will typically result in paralysis.
3: Lumbar Vertebrae (7); Bears most of the weight of the body and is imperative to back support. Holds and protects spinal cord, fracture typically results in paralysis.
4: Sacrum/Sacral Vertebrae; Base of tail, imperative to tail movement.
5: Cranium/Skull; Protects the brain, insertion site for neck muscles
6: Brain; Send messages via the nervous system to stimulate movement in the body
2: Thoracic Vertebrae (13); Holds the rib cage, protects heart and lungs dorsally. Also holds the spinal cord, and a fracture will typically result in paralysis.
3: Lumbar Vertebrae (7); Bears most of the weight of the body and is imperative to back support. Holds and protects spinal cord, fracture typically results in paralysis.
4: Sacrum/Sacral Vertebrae; Base of tail, imperative to tail movement.
5: Cranium/Skull; Protects the brain, insertion site for neck muscles
6: Brain; Send messages via the nervous system to stimulate movement in the body
Bones Anteriorly:
1: Os Coxae; Organ protection (bladder and uterus) and strong connection point for the muscles of the lower extremities
3: Sternum; Middle of ribcage, site for the costal cartilage to connect too, as it also protects the Lungs and the Heart, connection site for many major chest muscles
4: Ribs; Protect the Lungs and Heart, connection site for Serratus Ventralis
- 1a: Obturator Foramen; Openings for arteries, veins, and nerves to pass through and supply the muscles of the lower extremities
3: Sternum; Middle of ribcage, site for the costal cartilage to connect too, as it also protects the Lungs and the Heart, connection site for many major chest muscles
4: Ribs; Protect the Lungs and Heart, connection site for Serratus Ventralis
Bones of the Feet:
1: Metatarsals; Paw movement and support
2: Metacarpals; Paw movement and support
2: Metacarpals; Paw movement and support
What we Learned:
We learned a lot while dissecting the Skeletal System. What was most surprising to us was the fact that cats share almost all of the same bones that us humans do. It especially interesting to find bones that are almost identical to ours, like the Xiphoid Process, Tibia, Fibula, Radius and Ulna. It was intriguing to us to look at the metacarpals and metatarsals as well, as they were very different from ours. They were a lot longer, probably to account for the length and flatness of the paw. One of our favorites, though, was the Os Coxae. It was interesting looking at the Iliac Crest of the Os Coxae in the cat and comparing it to ours. It is a lot more narrow, and stretches farther superior than the Os Coxae, although this may be because our cat is a female and the possibility of housing fetuses was accounted for by the size of the Os Coxae.