The Skeleton: Bones and Joints Chapter 6 The Skeleton: Bones and Joints

The Skeleton Skeletal system is made up of bones, joints, and supporting connective tissue

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

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

The skeleton

The structure of a long bone.

Compact bone tissue

Bone tissue, longitudinal section

Checkpoint 6-1: A long bone has a long narrow shaft and two irregular ends. What are the scientific names for the shaft and the ends of a long bone? Shaft Diaphysis Ends Proximal epiphysis Distal epiphysis Checkpoint 6-2: What are the two types of osseus (bone) tissue and where is each type found? Spongy (cancellous) bone Found in the ends (epiphyses) of long bones Flat bones Compact bone Shafts of long bones Outer layers of flat bones

Bone Growth and Repair Types of bone cells Osteoblasts manufacture the matrix Osteocytes maintain and repair existing bone matrix Osteoclasts resorb bone tissue

Checkpoint 6-3: What are the three types of cells found in bone and what is the role of each? Osteocytes Maintain and repair bone existing bone matrix Osteoblasts Manufacture bone matrix Osteoclasts Resorb (break down) bone matrix

Formation of a Long Bone Bones begin as cartilage in the embryo Cartilage begins to turn into bone Osteoblasts build up bony matrix Epiphyseal plates develop across bone ends Bone growth takes place in epiphyseal plate Bones continue to lengthen Bones stop lengthening When epiphyseal plates (cartilage) turns to bone, they stop lengthening Bone resorption and formation continues Bone continues to be modeled (shaped)

Checkpoint 6-4: As the embryonic skeleton is converted from cartilage to bone, the intercellular matrix becomes hardened. What compounds are deposited in the matrix to harden it? Calcium compounds Checkpoint 6-5: After birth, long bones continue to grow in length at secondary centers. What are these centers called? Epiphyses Epiphyseal plate

Bone Markings Projections Depressions or holes Head Process Condyle Crest Spine Depressions or holes Foramen Sinus Fossa Meatus

Checkpoint 6-6: Bones have a number of projections, depressions, and holes. What are some functions of these markings? Projections Help form joints and serve as muscle attachments Depressions Serve as muscle attachments Holes Serve as passageways for nerves and blood vessels

Bones of the Axial Skeleton Axial skeleton—80 bones of the head and trunk Appendicular skeleton—126 bones of the extremities

Framework of the Skull Cranial bones Facial bones Infant skull Frontal Parietal Temporal Ethmoid Sphenoid Occipital Facial bones Mandible Maxillae Zygomatic Nasal Lacrimal Vomer Palatine Inferior nasal conchae Ossicle Hyoid Infant skull Fontanels

The skull. ZOOMING IN • What type of joint is between bones of the skull? Sutures

The skull, inferior view. ZOOMING IN • What two bones make up each side of the hard palate? Maxilla and palatine bones

Floor of cranium, superior view. ZOOMING IN • What is a foramen? A hole in a bone

The skull, sagittal section.

Infant skull, showing fontanels. ZOOMING IN • Which is the largest fontanel? Anterior fontanel

Framework of the Trunk Vertebral column Thorax Cervical vertebrae (7) Thoracic vertebrae (12) Lumbar vertebrae (5) Sacral vertebrae (sacrum) (4 fused) Coccygeal vertebrae (coccyx) (3 fused) Thorax Sternum Manubrium Clavicular notch Sternal angle Xiphoid process Ribs True ribs (1-7) False ribs (8-12) Floating ribs (11-12)

Vertebral column, left lateral view. ZOOMING IN • From an anterior view, which group(s) of vertebrae form a convex curve? Cervical and lumbar Which group(s) form a concave curve? Thoracic, sacrum and coccyx

The vertebral column and vertebrae.

The first two cervical vertebrae

Bones of the thorax, anterior view ZOOMING IN • To what bones do the costal cartilages attach? Sternum, ribs

Checkpoint 6-8: What are the five regions of the vertebral column? Checkpoint 6-7: The axial skeleton consists of the bones of the skull and the trunk. What bones make up the skeleton of the trunk? Vertebral column, ribs, sternum Checkpoint 6-8: What are the five regions of the vertebral column? Cervical, thoracic, lumbar, sacrum, coccyx

Bones of the Appendicular Skeleton Two divisions Upper Lower

The Upper Division of the Appendicular Skeleton The shoulder girdle Clavicle (collarbone) Scapula (shoulder blade) Supraspinous fossa and infraspinous fossa Acromion Glenoid cavity Coracoid process

The Upper Division of the Appendicular Skeleton The upper extremity Humerus (arm bone) Medial and lateral epicondyles Trochlea Capitellum Ulna (forearm bone) Distal projection (styloid process) Head (distal) Olecranon Trochlear notch (semilunar notch) Radius (lateral forearm bone) Head (proximal end) Carpal bones (wrist) Metacarpal bones (palm) Phalanges (finger bones)

The shoulder girdle and scapula ZOOMING IN • What does the prefix supra mean? Above What does the prefix infra mean? Below

The right humerus

Radius and ulna of the right forearm ZOOMING IN •What is the lateral bone of the forearm? Radius

Movements of the forearm

Left elbow, lateral view ZOOMING IN •What part of what bone forms the bony prominence of the elbow? The olecranon process of the ulna

Bones of the right hand, anterior view

The Lower Division of the Appendicular Skeleton 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

The pelvic bones ZOOMING IN • What bone is nicknamed the “sit bone”? Ischium

Comparison of male and female pelvis, anterior view

The Lower Division of the Appendicular Skeleton The lower extremity Femur (thigh) Greater trochanter Lesser trochanter Linea aspera Patella (kneecap) Tibia (shin bone of leg) Medial malleolus Fibula (leg bone) Lateral malleolus Tarsal bones (ankle) Calcaneus (heel bone) Metatarsal bones (instep) Phalanges (toe bones)

The right femur (thigh bone)

Tibia and fibula of the right leg ZOOMING IN • What is the medial bone of the leg? Tibia

Bones of the right foot   ZOOMING IN •Which tarsal bone is the heel bone? Calcaneous

Checkpoint 6-9: What division of the skeleton consists of the bones of the shoulder girdle, hip, and extremities? Appendicular

Skeletal Changes in the Aging Bones undergo significant changes Loss of calcium salts Decrease in protein Reduction in collagen Loss of height Decrease in chest diameter

The Joints Classified by material between adjoining bones and by degree of movement permitted Fibrous Synarthrosis (immovable) Cartilaginous Amphiarthrosis (slightly movable) Synovial Diarthrosis (freely movable)

Checkpoint 6-10: What are the three types of joints classified according to the type of material between the adjoining bones? Fibrous Cartilaginous Synovial

More About Synovial Joints Structures that support and protect synovial joints Ligaments Joint capsule Hyaline (articular) cartilage Fat Bursae

Structure of a synovial joint

The knee joint, sagittal section

Types of Synovial Joints Classified by types of movement they allow Gliding Bones of the wrist and ankle Hinge Elbow, interphalangeal joints Pivot Joint between C-1 and C-2, proximal radio-ulnar joint Condyloid 2nd-5th metacarpo-phalangeal joints (knuckles) Saddle Ist metacarpo-phalangeal joint (thumb) Ball-and-socket Hip, shoulder

Movement at Synovial Joints Flexion Extension Abduction Adduction Circumduction Rotation Movements characteristic of forearm and ankle Supination Pronation Inversion Eversion Dorsiflexion Plantar flexion

Movements at synovial joints

Checkpoint 6-11: What is the most freely movable type of joint? Ball and socket