Chapter 6 Bones and joints

skeleton Bones Joints Connective tissue

Functions of bones Several functions To serve as a firm framework for the body To protect delicate structures such as the brain and spinal cord To work as levers to produce movement To store calcium salts To produce blood cells

Bone structure Types of bone (osseous) tissue Compact bone Haversion systems (osteons) Spongy (cancellous) bone Bone marrow Red marrow Yellow marrow Bone membranes Periosteum Endosteum

Bone growth Types of bone cells Osteoblasts manufacture the matrix Osteocytes maintain and repair existing bone matrix Osteoclasts resorb bone tissue Ossification is conversion of cartilage to bone

Formation of long bone Cartilage begins to turn into bone Epiphyseal plates develop across bone ends Bones continue to lengthen Bones stop lengthening Bone resorption and formation continues

Bone markings Distinguishing features Projections – usually for muscle or ligament attachment Head Process Condyle Crest Spine Depressions or holes- to allow for articulations and innervation Foramen Sinus Fossa Meatus Page 93 gives good descriptions, we will explore more in lab

Bones of the axial skeleton Two main groups of bones Axial skeleton—80 bones of the head and trunk Appendicular skeleton—126 bones of the extremities

skull Cranial bones- occipital, parietal, temporal, frontal Facial bones- zygomatic, mandible, maxilla, sphenoid

Infant skull Infant skull- bones are not fused to allow passage through birth canal, fontanel= soft spot

Axial skeleton Vertebral column Cervical vertebrae Thoracic vertebrae Lumbar vertebrae Sacral vertebrae (sacrum) Coccygeal vertebrae (coccyx)

Atlas and axis

Thorax Sternum Ribs True ribs False ribs Manubrium Clavicular notch Sternal angle Xiphoid process

Appendicular skeleton Two divisions Upper Lower

Pectoral girdle The shoulder Clavicle (collarbone) Scapula (shoulder blade) Supraspinous fossa and infraspinous fossa Acromion Glenoid cavity Coracoid process

The upper extremity Humerus (arm bone) Medial and lateral epicondyles Trochlea

Radius and ulna Distal projection (styloid process) Olecranon Ulna and radius (forearm bones) Distal projection (styloid process) Olecranon Trochlear notch (semilunar notch) Radius (forearm bone)

Forearm movement

Elbow joint

hands Carpal bones (wrist) Metacarpal bones (palm) Phalanges (finger bones)

Pelvic girdle The pelvic bones (ossa coxae) Ilium Iliac crest Anterior superior iliac spine Ischium Ischial spine Ischial tuberosity Pubis Pubic symphysis Features of pelvis Acetabulum Obturator foramen

Male vs female pelvis Female pelvis is: More lighter in weight More flared ilia Pubic arch is wider Pelvic opening is wider Pubic outlet is larger Sacrum and coccyx are shorter and less curved

Legs The lower extremity Femur (thigh) Patella Greater trochanter Lesser trochanter Linea aspera Patella

legs Tibia (shin bone) Fibula (leg bone) Tarsal bones (ankle) Medial malleolus Fibula (leg bone) Lateral malleolus Tarsal bones (ankle) Calcaneus (heel bone) Metatarsal bones (instep) Phalanges (toe bones)

feet Tarsal bones (ankle) Metatarsal bones (instep) Calcaneus (heel bone) Metatarsal bones (instep) Phalanges (toe bones)

The aging skeleton Bones undergo significant changes Loss of calcium salts Decrease in protein Reduction in collagen Loss of height Decrease in chest diameter

Joints Classified by material between adjoining bones and by degree of movement permitted Fibrous Synarthrosis (immovable) Bones in our skull Cartilaginous Amphiarthrosis (slightly movable) wrist Synovial Diarthrosis (freely movable) elbow

Synovial joints Bones are joined by other structures in synovial joints Structures that support and protect synovial joints Ligaments Joint capsule Hyaline (articular) cartilage Medial meniscus and lateral meniscus Fat Bursae

knee

Types of synovial joints Classified by types of movement they allow Gliding Hinge Pivot Condyloid Saddle Ball-and-socket

movements Movements characteristic of forearm and ankle Supination- palm up Pronation- palm down Inversion- palm toward body Eversion- palm away from body Dorsiflexion- toe up Plantar flexion- pointed toe Flexion- bending Extension- straightening Abduction- moving away Adduction- coming toward Circumduction- moving in a circle Rotation- twisting