Meat and Bones

1. William Sweetman Meat and Bones

2. Skeletal System • Consists of bones, cartilage, joints, ligaments, and tendons • Made of connective tissues • Connective Tissue • Type of tissue in which the proportion of cells to extracellular matrix is small • Bone • A form of connective tissue, is one of the hardest tissues in the body

3. Ossification • The formation of bones from fibrous tissues, continues until maturity • Bone growth is balanced between the actions of osteoblasts and osteoclats • Osteoblasts: immature bone cells that produce bony tissue • Osteoclats: are phagocyte cells that eat away bone tissue from the medullary cavity of the bone

4. Ossification • When osteoblasts mature they become osteocytes • Red bone marrow, located in cancellous bone, is hematopoietic • Produces red blood cells, white blood cells, and clotting cells • The medullary cavity of bone, or inner space of bone, contains yellow bone marrow • In adult animals, yellow bone marrow replaces red marrow

5. Cartilage • Another form of connective tissue more elastic than bone • Articular cartilage • Covers the joint surfaces of bone • Meniscus • A curved fibrous cartilage found in some joints that cushions force applied to joints

6. Joints • Connections between bones • Classifications • Synarthroeses: allow no movement • Amphiarthroses: allow slight movement • Diarthroses: allow free movement • Suture: a jagged line where bones join and form a non-movable joint

7. Fontanelle: a soft spot remaining at a junction of sutures that usually close at birth Symphysis: a joint where two bones join and are held firmly together so they form a junction Ball-and-sock joints: a wide range of motions in many directions Joints

8. Ligaments and Tendons Ligaments: a band of fibrous connective tissue that connect bones Tendons: A band of fibrous connective tissues that connect muscle to bones Brusa: a fibrous sac that acts as a cushion to ease movement in areas of friction

9. Synovial Membrane and Fluid • Synovial Membrane: the inner lining of Bursae and synovial joints • Secretes synovial fluid which acts as a lubricant to make joint movement smooth

10. Axial and Appendicular Skeleton • Axial • The frame work of the body • Appendicular • Consists of extremities, shoulder, pelvic griddle, and cranium • Vertebral Colum • Supports the head and body, and protects the spinal cord

11. Body • Solid portion ventral to the spinal cord; midline portion • Arch • The dorsal part of the vertebrae that surrounds the spinal cord • Lamina: the left or right dorsal halves of the arch • Spinous process: a single projection from the dorsal part of the vertebral arch

12. Transverse and Articular process • Transversal process: project laterally from the right and left sides of the vertebral arch • Articular process: are paired cranial and caudal projections located on the dorsum of the vertebral arch • Vertebral foramen: an opening in the midline of the vertebra through which the spinal cord passes through

13. Bone classifications • Ribs: paired bones attached to the thoracic vertebra • Sternum: the breastbone, forms midline ventral portion of rib cage • Manubrium: the cranial portion • Xiphoid: the caudal portion • Thoracic cavity: protects hearts and lungs

14. Bone classifications Scapula: the shoulder blades Clavicle: the collarbone Humorous: the long bone of the proximal limb Radius: the cranial bone of the front limb Ulna: the caudal bone of the front limb Olecranon: proximal projection found in the ulna

15. Bone classifications • Carpal bones: irregular shaped in the area known as the wrist • Metacarpals; bones found distal to the carpals • Splint bones: in horses metacarpals 2 and 4 do not articulate with the phalanges • Interosseous: splint bones attached by ligaments to the large third metacarpal (cannon bone)

16. Bone classifications • Phalanges: the bones of the digits • Digit: bones analogous to the human figure • Sesamoid bones: small nodular bones embedded in a tendon or joint capsule • Femur: the proximal long bone of the rear • Patella: a large sesamoid bone in the rear limb • Tibia: the larger and more weight bearing bone

17. Bone classifications • Fibula: a long slender bone • Ambulation: a type of movement involving running, walking, or moving from one place to another • Fascia: a sheet of fibrous connective tissue that covers, supports, and separates muscles • Linea alba: a fibrous band of connective tissue on the ventral abdominal wall

18. Pelvis • Three main parts; the hip • Ilium: the largest pair, blade shaped • Ischiam: the caudal part of the bones • Pubis: the ventral pair of bones that are fused on the midline by a cartilaginous joint • Acetabalum: the largest socket of the pelvic bone that forms where the 3 bones meet

20. Ranges of Motion • Abductor: muscle that moves away from midline • Adductor: muscle moves towards midline • Flexor: muscle that bends at its joint • Extensor: muscle that straightens • Levator: muscle that rises • Rotator: muscle that rotates

21. Ranges of Motion • Depressor: muscle that lowers • Supinator: muscle that rotates • Pronator: muscle that rotates

22. Muscles and locations • Pectoral: chest • Epaxial: pelvic axis • Intercostal: between the ribs • Infraspinatus: located beneath the spine of the scapula • Supraspinatus: located above the spine of the scapula • Orbicularis: muscles surrounding another structure