Skeletal System: Bones and Joints

Diarthrosis

freely movable joint e.g. knee, elbow and wrist articulations

synarthrosis, amphiarthrosis, diarthrosis

functional classification of joints

Bone growth

occurs by the deposition of new bone lamellae onto existing bone or other connective tissue. This process is called APPOSITIONAL GROWTH

Proteoglycans

-Are large molecules consisting of many polysaccharides attaching to encircling core proteins. Form large aggregates and attract water

Atlas

1st vertebra, holds the head

7 Cervical region 12 Thoracic Region 5 Lumbar region Sacral Region Coccygeal Region

26 individual bones in the vertebral column

Axis

2nd vertebra rotates head

Frontal Bone Parietal Occipital Temporal Sphenoid Ethmoid

8 Cranial Bones

Cervical region curves anterior Thoracic Region curves posterior Lumbar region curves anterior Sacral Region and Coccygeal Region curves posterior

Adult vertebral column has four major curvatures

Hyoid Bone

An unpaired, U shaped bone

Frontal bone

Anterior part of cranium

Ethmoid Bone(NASAL CONCHAE)

Anterior portion of cranium

short bones

Approximately as wide as they are long

Trabeculae

Are interconnecting rods, and spaces that contain marrow

Articulations

Are where two bones come together

Inferior Nasal Conchae

Attached to lateral walls of nasal cavity

•Removal of existing bone by osteoclasts •Deposition of new bine by osteoblast •Occurs in all bones •Responsible for changes in bone shape, bone repair, adjustment of bone to stress •Calcium ion regulation

Bone Remodeling

Foramen: Hole Fossa: Depression Process: Projection Condyle: Smooth, rounded end Meatus: Canal-like passageway Tubercle: Lump of bone

Bone anatomical terms

Osteoblast, Osteocytes and Osteoclast

Bone cells

primary ossification center

Bone formation in the diaphysis of a long bone

1. broken bone causes bleeding and a blood clot forms. 2. callus forms which is a fibrous network between 2 fragments 3. cartilage model forms first then, osteoblasts enter the callus and form cancellous bone. 4.Cancellous bone is slowly remodeled to form compact and cancellous bone.

Bone repair:

Osteoclasts

Bone-destroying cells. They break down the bone matrix for remodeling and the release of calcium.

Scapula(shoulder blade) Clavicle(collar bone)

Bones of the pectoral girdle

Parathyroid Hormone(PTH) and Calcitonin

Calcium homeostasis is maintained by

Hydroxyapatite

Calcium phosphate crystals are called

Osteocytes

Cells that maintain bone matrix

Zygomatic Bones

Cheek bones

Is a tough, rope like protein

Collagen

The matrix contains

Collagen, ground substances and other organic molecules, as well as water and minerals

Bone, cartilage, tendons, and ligaments of the skeletal system are all

Connective tissues

Articular Cartilage

Covers epiphysis, Reduces Friction

1. Decreased collagen production 2. Loss of bone density 3. Degenerative changes

Effects of Aging on the Skeletal System and Joints

Epiphysis

Ends spongy bone tissue

Maxillae Palatine bones Zygomatic Bones Lacrimal Bones Nasal Bones Vomer Inferior Nasal conchae Mandible

Facial Bones

Sphenoid Bone(Sella Turcica)

Forms part of cranium floor, lateral posterior portions of eye orbits,

palatine bones

Forms the posterior portion of hard plate, lateral wall of nasal cavity

Epiphyseal plate

Growth in the length of a bone, which is the major source of increased height in an individual occurs in?

Irregular bones

Have shapes that do not fit readily into the other three categories

Ischium

Inferior and posterior region

Temporal bone(temporomandibular joint)

Inferior to parietal bones on each side of cranium

Axial Skeleton

Is composed of the skull, the vertebral column and the thoracic cage.

yellow marrow

Is mostly fat

Ossification

Is the formation of bone by osteoblast

Red marrow

Is the location of blood forming

Synovial

Joint by fluid cavity Most joints of the appendicular skeleton

Rope like collagen fibers

Lend flexible strength to the bone

Spongy bone

Located at the epiphysis of long bones and center of other bones

Outer part of diaphysis(long bones)

Location of compact bone

Diaphysis Epiphysis Articular cartilage Epiphyseal cartilage Medullary Cavity Periosteum Endosteum

Long bone Structures

Mandible

Lower jawbone

Femur(thigh) Patella(knee cap) Tibia(large lower leg) Fibula(small lower leg) Tarsals(ankle) Metatarsals(foot) Phalanges(toes and fingers)

Lower limb bones

Collagen

Makes cartilage tough

Lacrimal bones

Medial surfaces of eye orbits

Periosteum

Membrane around bones outer surface

Vomer

Midline of nasal cavity

Bone compression(weight bearing) strength

Mineral components give

Bine compression(weight-bearing) strength

Mineral in bone is in the form of?

New borns

Most bones have blood making red bone marrow

Abduction

Movement away from the midline of the body

Rotation

Movement of a structure about the long axis

Adduction

Movement toward the midline of the body

Paranasal Sinuses

Nasal Cavity have large cavities within them, called

Synarthrosis

Non-movable joint e.g skull bone articulations

Frontal Ethmoid Sphenoid maxillary

Paranasal sinuses are

Occipital Bone

Posterior portion and floor of cranium

Thoracic cage

Protects vital organs and has 12 pairs of ribs

Adults

Red marrow in the diaphysis is replaced by yellow bone marrow

Flat bones

Relatively thin, flattened shape

Osteoblast

Responsible for the formation of bone and the repair and remodeling of bone

Pronation

Rotation of the forearm with palms down

Supination

Rotation of the forearm with palms up

Diaphysis

Shaft, Compact bone tissue(on outside)

marrow

Spaces filled with soft tissue

Extension

Straightening of a joint

Vertebral column or spine

The central axis of the skeleton

tendons and ligaments

Their extracellular matrix contains large amounts of collagen fibers, making these structures very tough, like ropes or cables

long, short, flat, irregular

There are four bone shape classifications

Flexion Extension Abduction Adduction Pronation Supination Rotation

Types of movement

Humerus(upper limb) Ulna(forearm) Radius(forearm) Carpals(wrist) Metacarpals(hand)

Upper limb bones

Pelvic girdle

Where lower limbs attach to body

True ribs (1-7)

attach directly to sternum

false ribs (8-12)

attach indirectly to sternum

Flexion

bending a joint

secondary ossification center

bone formation in the epiphysis

endochondral ossification

bone formation that occurs inside hyaline cartilage

intramembranous ossification

bone formation that occurs within connective tissue membranes is called?

components of skeletal system

bone, cartilage, tendons, ligaments

Sternum

breastbone

medullary cavity

center of diaphysis, red or yellow marrow

Central canal

center of osteon, contains blood vessels

bone extracellular matrix

contains collagen and minerals, including calcium and phosphate

Cartilage extracellular matrix

contains collagen and proteoglycans

Bone reabsorption

contribute to bone repair and remodeling by removing existing bone are called

Nasal Bones

form the bridge of the nose

Maxillae

forms the upper jaw

Supports body weight Protects spinal cord Allows spinal nerves to exit the spinal cord Provides site for muscle attachment Provides movement of the head and trunk

functions of vertebral column

Acetabulum

hip socket(joint)

Pelvis

includes pelvic girdle and coccyx

long bones

longer than they are wide

Endosteum

membrane that line medullary cavity

Ilium

most superior region

Floating ribs

not attached to sternum

Lamella

rings of bone matrix

Parietal Bones

sides and roof of cranium

Epiphyseal plate

site of growth, between diaphysis and epiphysis

Amphiarthrosis

slightly movable joint e.g between vertebrae

Lacunae

spaces between lamella

1.Chondroblasts build a cartilage model, the chondroblasts become condrocytes. 2.cartilage model calcifies 3. Osteoblast invade calcified cartilage, the primary ossification forms diaphysis 4.Secondary Ossification centers epiphysis 5.Original cartilage model is almost completely ossified and remaining cartilage is the articular cartilage

steps of endochondral ossification

Fibrous joint Cartilaginous joint Synovial joint

structural classifications of joints

Osteon

structural unit of compact bone

skeletal system functions

support, protection, movement, storage, blood cell production

Canaliculus

tiny canals that transport nutrients and remove waste

Cartilaginous joints

united by cartilage Subclasses are synchondroses and symphysis

fibrous joints

united by fibrous connective tissue Subclasses are sutures, syndesmosos, and gomphoses