Skeletal System

Vocabulary Ax-: axis -blast: bud Carp-: wrist -clast: break Fov-: pit Glen-: joint socket Intra-: inside Meat-: passage Odont-: tooth Oste-: bone Poie-: produce, make

Skeletal System Bones are made of osseous tissue Functions: Protect and support Body movement Blood cell formation (hematopoiesis) Storage of inorganic salts (K, Ca, P)

Structure 206 bones 2 divisions

Divisions of the Skeleton Axial: Skull, hyoid bone, vertebral column, thoracic cage, sternum Appendicular: limbs, pectoral girdle (shoulders), pelvic girdle (hips) Meatus: a natural body opening or canal Process: a projecting part Foramen: a natural opening through which nerves and blood vessels pass through Articulation: a place of anatomical union, usually movable, between 2 or more bones Fossae: a cavity or depression in a bone

Axial Skeleton Cranium (skull): encloses and protects the brain Supraorbital foramen: passage way for blood vessels and nerves Foramen magnum: the large opening where the spinal cord attaches to the brain External acoustic meatus: leads to the inner ear Mandibular fossae: articulations on the mandible Mastoid process: place where neck muscles attach Styloid process: place where the tongue attaches Zygomatic process: forms the cheek

label the skull

Axial Skeleton Vertebral column Cervical (7) Thoracic (12) Lumbar (5) Axis #1 (side to side) Atlas #2 (up and down) Thoracic (12) Where ribs attach Lumbar (5) Support most body weight Sacrum: 5 fused vertebrae Coccyx: (tailbone) 4 fused vertebrae Intervertebral disks: shock absorbers Vertebral foramen: space where spinal cord goes through

Axial Skeleton Thoracic cage (12 ribs) True ribs (7) attach to sternum False ribs (3) share attachment site Floating ribs (2) do not attach to sternum, only vertebrae Sternum Manubrium: upper section Body: middle section Xiphoid process: lower projection

Appendicular Skeleton Pectoral girdle: connects the bones of the upper limbs to the axial skeleton Scapula: shoulder blades Clavicles: collar bones Humerus: upper arm bone Radius: larger bone in the forearm Ulna: smaller bone in the forearm Carpals: 8 wrist bones Metacarpals: 5 palm bones Phalanges: 14 finger bones

Appendicular Skeleton Pelvic girdle: connects the bones of the lower limbs to the axial skeleton Pelvis: includes the sacrum, coccyx and pelvic girdle Ilium: largest hip bone Ischium: lower hip bone Pubis: anterior hip bone Femur: thigh bone Patella: knee cap Tibia: larger lower leg bone Fibula: small lower leg bone Tarsals: 7 ankle bones Metatarsals: 5 foot bones Calcaneus: heel bone Phalanges: 14 toe bones

Appendicular Skeleton

Long bones

Parts of a long bone Spongy bone: (cancellous) bone with spaces in it Compact bone: (cortical) bone with no spaces in it Periosteum: a covering of dense connective tissue around bone Articular cartilage: hyaline cartilage around the end of the epiphysis Collagen: the protein that gives bones their strength

Bone Growth and Development Matrix: where the bones cells live Osteocytes: mature bone cells Osteoblasts: cells that will differentiate to form bone cells Osteoclasts: cells that dissolve bone Ossification: the formation of bone

Bone growth and formation All bones start as hyaline cartilage and then turn to bone later Bones are constantly being broken down by osteoclasts and formed by osteoblasts

Bone growth and formation Factors that influence bone growth and repair Nutrition: Vitamin D is needed so that bones have enough calcium Hormones: growth hormones stimulate osteoblasts and sex hormones stimulates ossification Physical exercise: exercise stimulates osteoblast formation

Bone Function Storage of inorganic salts: Calcium (Ca) Phosphorous (P) Magnesium (Mg) Sodium (Na) Potassium (K) and Carbonate (CO₃) nerve impulses, blood clotting, muscle movement and other metabolic processes

Hematopoiesis Medullary cavities: hollow chambers filled with bone marrow Red Bone marrow: where erythrocytes, leukocytes and platelets are made Yellow bone marrow: where fat is stored Hematopoiesis: red blood cell formation

Broken bones Bone fracture type 1: Greenstick: incomplete fracture, break on the surface Fissured: incomplete longitudinal break Comminuted: complete fracture with bone fragmentation

Bone Fractures Bone fractures Type 2 Transverse: complete fracture that is across the bone Oblique: complete fracture that is at a tilted angle Spiral: complete fracture that is caused by twisting a bone

Joints and Tendons Ligaments: attach bone to bone Tendons: attach muscle to bone

Types of Joints Synarthrotic: immovable (sutures) Amphiarthrotic: slightly moveable (vertebrae) Diathrotic: movable (knee) Synovial fluid: fluid around the joints that helps to lubricate them Synovial Joints Ball and socket (shoulder) Hinge (elbow, knee) Pivot (ulna and radius) Saddle (wrist, ankle)

Problems in Joints Sprains: overstretching or tearing of connective tissue Bursitis: over use of a joint causing the bursa to become inflamed Arthritis: joint inflammation Causes: bacterial infection Immune system disorders Degeneration of cartilage with age