Skeletal System PDF

DAVAO DEL SUR STATE COLLEGE A State College for the ASEAN and Beyond SKELETAL SYSTEM  Skeletal System Refers to the framework of hard structures (bones and cartilages) which supports and protects the soft tissues of animals. Function of the skeleton Support the body Levers for locomotion...

DAVAO DEL SUR STATE COLLEGE A State College for the ASEAN and Beyond SKELETAL SYSTEM  Skeletal System Refers to the framework of hard structures (bones and cartilages) which supports and protects the soft tissues of animals. Function of the skeleton Support the body Levers for locomotion Protect soft parts www.dssc.edu.ph Skeletal System Bone Primary skeletal tissue - Mineral homeostasis (reserve of calcium, phosphate, and other ions) - provides support and makes Red Blood Cells www.dssc.edu.ph The Structure of A Bone Epiphysis - refer to either end of a long bone. Diaphysis- the cylindrical shaft of a long bone between the two epiphysis. Articular cartilage – thin layer of articular cartilage that covers the articular (joint) surface of a bone. Periosteum - A tough fibrous membrane that covers the outer surface of a bone except where the articular cartilage is located. Endosteum – fibrous membrane that lines the marrow cavity. www.dssc.edu.ph The Structure of A Bone Compact bone (the outer layer)- is a dense layer of cells in a hard matrix of protein fibers and compounds made of calcium and other minerals. This is the layer that gives bones their amazing strength. Spongy bone (the middle layer) is, like compact bone, a variety of cell types within a matrix of mineralized protein fibers. In adults, the spongy bone contains the red marrow. www.dssc.edu.ph The Structure of A Bone Medullary cavity and bone marrow is the inner layer in the shaft of a long bone (the diapHysysis) and the inner portion of other bones. Yellow marrow, which is mostly fat (think butter) Red marrow, the site of hematopoiesis, the production of blood cells. In young, medullary cavities of the long bones are mostly filled with red marrow. www.dssc.edu.ph www.dssc.edu.ph  How the skeleton develops? 1. When long bones develop in a fetus, they’re formed from hyaline cartilage. 2. Bone shape is determined by the shape of the cartilage, so it serves as a template. 3. Calcium, are deposited onto the template, and the cartilage becomes calcified in the endochondral ossification process. 4. The skeleton isn’t fully ossified at birth. (Ever notice the “rubbery” feel?). 5. As animals grow, ossification and bone growth occur simultaneously — the cartilage cells divide, the bone lengthens, and the cartilage becomes calcified. 6. Eventually, the only areas of growth are the epiphyses at the ends of certain bones. 7. When adult height is reached, the cartilage cells in the epiphyses no longer divide, and the bone stops growing in length. www.dssc.edu.ph  That’s not the end of the bone development story. Bone development continues throughout life, in a constant process of minerals being deposited in and dissolved out, and the birth, growth, and death of cells. A similar process, but slower and less active, occurs in cartilage. Early in life, the processes of building are more active. As animal ages, building slows but never actually stops. The destructive processes continue or even accelerate and the entire skeleton gradually shrinks and weakens. www.dssc.edu.ph Classifying bones Long Bones Provide support for the body giving it the rigidity (hardness) necessary to stand and move. Longer than wide three primary ossification centers (1 diaphysis and 2 epiphyses) Example: femur, humerus, www.dssc.edu.ph Classifying bones Short bones cube-shaped; Protect long bones by being flexible Cushion shock Diminish friction Example: carpals and tarsals www.dssc.edu.ph Classifying bones Flat bones Relatively thin and flat and usually curved; are longer and wider than they are thick Protect vital organs such as the brain, the heart, and the lungs Usually multiple bones fused together Example: scapula, pelvis, skull www.dssc.edu.ph Classifying bones Irregular bones No uniformity in development Important to the protection and support of the central nervous system Points of some muscle attachment Examples: Vertebrae www.dssc.edu.ph Classifying bones Pneumatic bones are found in the skeleton of birds. They are lined by mucous membrane rather than the marrow and they communicate with the respiratory system. www.dssc.edu.ph Classifying bones Aberrant Long Bones Ribs cannot be satisfactorily included in the above groups. www.dssc.edu.ph Classifying bones Sesamoids bones which are developed in tendons to afford increased leverage. Examples: patella and the navicular bone www.dssc.edu.ph Parts Of Skeleton The skeleton may be divided primarily into three parts: 1. Axial- skull, vertebral column, ribs, and sternum 2. Appendicular – bones of the limbs and bones connecting the limbs to the axial skeleton 3. Splanchnic –  os cordis (cattle)  os rostri (pig) www.dssc.edu.ph www.dssc.edu.ph www.dssc.edu.ph Axial Skeleton Skull many plates of bone fused together. skull of mammals consists of separate bones that grow together during development to form a solid case protecting the brain and sense organs. www.dssc.edu.ph Axial Skeleton Skull: HORSE  Has facial crest in the maxilla www.dssc.edu.ph Axial Skeleton Skull: HORSE www.dssc.edu.ph Axial Skeleton Skull: HORSE  Orbit is complete www.dssc.edu.ph Axial Skeleton Skull: HORSE Has upper incisors www.dssc.edu.ph Axial Skeleton Skull: POLLED CATTLE  Has facial tuber in the maxilla  Horned animals have cornual process; www.dssc.edu.ph Axial Skeleton Skull: POLLED CATTLE  Orbit is complete www.dssc.edu.ph Axial Skeleton Skull: POLLED CATTLE  Absence of upper dental incisors www.dssc.edu.ph Axial Skeleton Skull: POLLED CATTLE www.dssc.edu.ph Axial Skeleton Skull: PIG  Unique bone in the nose -> os rostri  Orbit is incomplete www.dssc.edu.ph Axial Skeleton Skull: PIG  Unique bone in the nose -> os rostri www.dssc.edu.ph Axial Skeleton Skull: PIG  Orbit is incomplete www.dssc.edu.ph Axial Skeleton Vertebral Column Equine - C7 T18 L6 S5 Cd 15-21 www.dssc.edu.ph Axial Skeleton Ribs www.dssc.edu.ph Axial Skeleton Ribs www.dssc.edu.ph Axial Skeleton Ribs www.dssc.edu.ph Axial Skeleton Ribs and Sternum There is always one more pair of sternal ribs that there are sternebrae. www.dssc.edu.ph Appendicular Skeleton bones of the limbs and bones connecting the limbs to the axial skeleton www.dssc.edu.ph Appendicular Skeleton www.dssc.edu.ph Appendicular Skeleton www.dssc.edu.ph Appendicular Skeleton www.dssc.edu.ph Appendicular Skeleton www.dssc.edu.ph Appendicular Skeleton Forelimb  Scapula  Humerus  Ulna  Radius  Carpus  Metacarpus  Phalanges www.dssc.edu.ph Appendicular Skeleton Hindlimb  Pelvis  Femur  Tibia  Fibula  Tarsus  Metatarsus  Phalanges www.dssc.edu.ph Lets look at the Skeletal Systems of different Animals www.dssc.edu.ph Schematic skeleton of Cattle www.dssc.edu.ph www.dssc.edu.ph www.dssc.edu.ph www.dssc.edu.ph www.dssc.edu.ph www.dssc.edu.ph www.dssc.edu.ph DAVAO DEL SUR STATE COLLEGE A State College for the ASEAN and Beyond POULTRY OSTEOLOGY Poultry Osteology Skeleton is lighter compared to mammals High number of cervical vertebrae Fusion of most vertebrae Prominent sternum Strong pectoral girdle Fusion or elimination of some limb bones www.dssc.edu.ph www.dssc.edu.ph Skull  3 main parts Brain case Bony orbit Beak www.dssc.edu.ph Vertebral Column www.dssc.edu.ph Sternum www.dssc.edu.ph Forelimb Scapu la www.dssc.edu.ph Forelimb www.dssc.edu.ph Forelimb www.dssc.edu.ph Forelimb Humer Uln us a Radiu s www.dssc.edu.ph Forelimb www.dssc.edu.ph Hindlimb www.dssc.edu.ph Hindlimb Fem ur www.dssc.edu.ph www.dssc.edu.ph