1. The Skeletal System Mrs. Higgins, LVT Locust Trace Agriscience Center Veterinary Assistant Program

2. Functions External structure and appearance for most vertebrate animals Provide protection of ______________ (take a guess) Give rigidity and form to the body Act as levers Store minerals _______________ and _______________ Form the cellular elements of blood Vital organs CalciumPhosphorus

3. What am I made of? The skeletal system is made of various forms of connective tissue o They all work together to provide structure and movement Consists of: o Bone o Joints o Cartilage o Ligaments/Tendons

4. Terminology OsteoblastsOsteoclasts Oste/o ____________ -blasts ____________ Immature bone cells that produce bony tissue, become osteocytes Oste/o __________ -clasts ___________ Eat away bony tissue from medullary cavity Immature Break Bone

5. Terminology Parts of the bone o Diaphysis Shaft of the long bone o Epiphysis Either end of the long bone o Epiphyseal Cartilage Layer of cartilage within the metaphysis of an immature bone that separates the diaphysis from the epiphysis. Location of growth o Metaphysis In a mature bone; flared area by the epiphysis o Periosteum Fibrous membrane that covers the surface of the bone o Medullary Cavity “marrow cavity”; In young animals, filled with red marrow (hematopoietic tissue)

6. Bone Marrow Hematopoietic o Hemat/o- blood o -poietic: pertaining to formations Forms blood cells (red cells and white cells) In adult animals, red marrow is replaced by yellow marrow. This is mostly fat cells, serves as fat storage area.

7. Cartilage A form of connective tissue More elastic and flexible than bone Articular cartilage o Covers the joint surfaces of the bone Meniscus o Curved fibrous cartilage found in some joints o Acts as cushion from force o Example….. Stifle/knee

8. Cartilage

9. Joints Also called articulations Form the connection between bones Different types depending on degree of movement 1.Fibrous 2.Cartilaginous 3.Synovial There are many within each category above, but we will cover a few from each

10. Fibrous Joints No joint cavity, no movement Example o Suture joint : between bones of the skull. Suture joints often completely ossify in maturity

11. Cartilaginous Joints Bones are united by cartilage with no joint cavity Limited movement Example o Symphyses joints: joined by flattened disks of fibrocartilage as found between the pelvic bones (birth canal) or between vertebrae

12. Synovial Joints Moveable joints Examples o Ellipsoid Joint: when a row of small bones fit against a long bone (carpus or tarsus) o Spheroid Joint: “ball and socket”; movement in nearly any direction. Spherical head of one bone fits into the depression of another bone. (Example is….. ______________________) o Hinge joints: allows for movement in one direction. Example __________________ o Pivot joint: movement occurs around one axis. Example ___________________________ Hip joint Knee or stifle Atlas/axis joint of neck

13. Synovial Joints Ellipsoid

14. Synovial Joint Spheroid (ball and socket)

15. Synovial Joins Hinge Joint

16. Synovial Joint Pivot Joint

17. Terms of Movement Adduction o Movement towards midline Abduction o Movement away from midline Flexion o Closure of a joint angle o Reducing angle Extension o Straightening of joint o Increasing the angle Hyperflexion o When a joint is flexed or extended too far

18. Movement Terms

19. Tendons Connective tissue that attaches muscle to bone.

20. Ligament Connective tissue that attaches bone to bone

21. The Skeleton

22. Broken into two parts Axial Skeleton: the central skeleton consisting of the skull, vertebral column, and ribs Appendicular skeleton: Limbs/Appendages (thoracic limbs and pelvic limbs) **Most of the skeletal system will be the same for different species of animals…. However, there will be differences in the feet/legs and the vertebral column of each animal. Why??

23. Vertebral Column Made up of many individual vertebra (singular) or vertebrae (plural) Numbered from head to tail and grouped into sections o Cervical o Thoracic o Lumbar o Sacral o Coccygeal Two of the vertebra have names o C1: atlas o C2: axis

25. Thoracic Limbs The forequarters carry up to 70% of the body weight of animals Consists of o Scapula o Humerus o Radius o Ulna o Carpal bones o Metacarpal bones o Phalanges

26. Pelvic Limbs Carry less weight (about 30%) but are heavily muscled Consist of o Pelvis o Femur o Patella o Tibia o Fibula o Tarsal Bones o Metatarsal bones o Phalanges *Sesmoid bone: small bone held in place by tendon (patella)

27. Let’s Label!!

29. Do you see the differences?

30. Dog Swine Cattle Horse Different numbers of metacarpal bones and phalanges present

31. Horse Lower Leg P1 or long pastern or proximal phalanx P2 or short pastern or middle phalanx P3 or coffin bone or distal phalanx **The horse industry uses long and short pastern and coffin bone

32. Great Interactive Websites http://www2.ca.uky.edu/agripedia/agmania/intera ctive/ http://www2.ca.uky.edu/agripedia/agmania/intera ctive/ http://www.real3danatomy.com/bones/dog- skeleton-3d.html http://www.real3danatomy.com/bones/dog- skeleton-3d.html http://www.vet.osu.edu/assets/flash/education/out reach/games/skeleton/skeleton.html http://www.vet.osu.edu/assets/flash/education/out reach/games/skeleton/skeleton.html