BO N E S A N D J O I N T S

CHAPTER 6

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

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)• Greater trochanter• Lesser trochanter• Linea aspera

• Patella

LEGS

• Tibia (shin bone)• Medial malleolus

• Fibula (leg bone)• Lateral malleolus

• Tarsal bones (ankle)• Calcaneus (heel bone)

• Metatarsal bones (instep)

• Phalanges (toe bones)

FEET

• Tarsal bones (ankle)• 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

• Flexion- bending

• Extension- straightening

• Abduction- moving away

• Adduction- coming toward

• Circumduction- moving in a circle

• Rotation- twisting

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