Bone Classification
Long Bones
Short Bones
Sesamoid Bones
Flat Bones
Irregular Bones
Intramembranous Bones
originate within sheetlike layers of connective tissues
they are the broad, flat bones
Endochondral Bones
Bones begin as hyaline cartilage
These are most bones of the skeleton
First layer of cells
Closest to the end of epiphysis
Resting cells
Anchors epiphyseal plate to epiphysis
Second layer of cells
Many rows of young cells
Undergoing mitosis
Third layer of cells
Older cells
Left behind when new cells appear
Cells enlarging and becoming calcified
Fourth layer of cells
Thin
Dead cells
Calcified extracellular matrix
Bone Resorption
action of osteoclasts and parathyroid hormone aka parathormone aka PTH
Factors that Affect Bone Development, Growth, and Repair
Deficiency of Vitamin A
Deficiency of Vitamin C
Deficiency of Vitamin D
Insufficient Growth Hormone
Excessive Growth Hormone
Insufficient Thyroid Hormone
Sex Hormones
Physical Stress
Deficiency of Vitamin A
retards bone development
Deficiency of Vitamin C
results in fragile bones
Deficiency of Vitamin D
rickets, osteomalacia
Insufficient Growth Hormone
dwarfism
Excessive Growth Hormone
gigantism, acromegaly
Insufficient Thyroid Hormone
delays bone growth
Sex Hormones
promote bone formation; stimulate ossification of epiphyseal plates
Physical Stress
stimulates bone growth
Bone Function
Gives shape to head, etc.
Supports body's weight
Protects lungs, etc.
Bones and muscles interact
When limbs or body parts move
Blood Cell Formation
Also known as hematopoiesis
Occurs in the red bone marrow
Inorganic Salt Storage
Calcium
Phosphate
Magnesium
Sodium
Potassium
Divisions of the Skeleton
Axial Skeleton
Appendicular Skeleton
Axial Skeleton
Skull
Spine
Rib cage
Appendicular Skeleton
Upper limbs
Lower limbs
Shoulder girdle
Pelvic girdle
Lifespan Changes for bones
Decrease in height at about age 30
Calcium levels fall
Bones become brittle
Osteoclasts outnumber osteoblasts
Spongy bone weakens before compact bone
Bone loss rapid in menopausal women
Hip fractures common
Vertebral compression fractures common
joint functions
Known as articulations
Functional junctions between bones
Bind parts of skeletal system together
Make bone growth possible
Permit parts of the skeleton to change shape during childbirth
Enable body to move in response to skeletal muscle contraction
Classification of Joints
Fibrous joints
Cartilaginous joints
Synovial joints
Fibrous joints
Dense connective tissues connect bones
Between bones in close contact
Cartilaginous joints
Hyaline cartilage or fibrocartilage connect bones
Synovial joints
Most complex
Allow free movement
Synarthrotic joints
Considered immovable
Amphiarthrotic joints
Slightly movable
Diarthrotic joints
Freely movable
types of fibrous joints
Syndesmosis
Suture
Gomphosis
Syndesmosis
Amphiarthrotic
A sheet or bundle of fibrous tissue connecting bones
Lies between tibia and fibula
Suture
Synarthrotic
Between flat bones
See teeth-like projections
Thin layer of connective tissue connects bones
Skull
Gomphosis
Synarthrotic
Cone-shaped bony process in a socket
Tooth in jawbone
types of cartilaginous joints
Synchondrosis
Symphysis
Synchondrosis
Synarthrotic
Bands of hyaline cartilage unite bones
Epiphyseal plate
Between manubrium and the first rib
Symphysis
Amphiarthrotic
Pad of fibrocartilage between bones
Pubic symphysis
Joint between bodies of adjacent vertebrae
General Structure of a Synovial Joint
Synovial joints are freely moveable
Joint cavity
Joint capsule
Synovial membrane
Synovial fluid
Bursae
types of synovial joints
Pivot Joint
Hinge Joint
Saddle Joint
Condylar Joint
Ball-and-Socket Joint
Gliding Joint
Pivot Joint
between proximal ends of radius and ulna
Hinge Joint
Elbow joint
Between phalanges
Saddle Joint
Between carpal and 1st metacarpal of thumb
Condylar Joint
Between metacarpals and phalanges
Between radius and carpals
Ball-and-Socket Joint
Hip joint
Shoulder joint
Gliding Joint
Between carpals
Between tarsals
Between facets of adjacent vertebrae
Examples of Synovial Joints
Shoulder Joint
Elbow Joint
Hip Joint
Knee Joint
Shoulder Joint
Ball-and-socket
Head of humerus and glenoid cavity of scapula
Loose joint capsule
Bursae
Ligaments prevent displacement
Very wide range of movement (circumduction
Elbow Joint
Hinge joint
Trochlea of humerus
Trochlear notch of ulna
Gliding joint
Capitulum of humerus
Head of radius
Flexion and extension
Many reinforcing ligaments
Stable joint
Hip Joint
Ball-and-socket joint
Head of femur and acetabulum of coxa
Heavy joint capsule
Many reinforcing ligaments
Less freedom of movement than shoulder joint
Circumduction
Knee Joint
Largest joint
Most complex
Medial and lateral condyles of distal end of femur and
Medial and lateral condyles of proximal end of tibia and
Femur articulates anteriorly with patella
Strengthened by many ligaments and tendons
Menisci separate femur and tibi
Lifespan Changes of joints
Joint stiffness is an early sign of aging
Fibrous joints first to change; can strengthen however over a lifetime
Changes in symphysis joints of vertebral column diminish flexibility and decrease height
Synovial joints lose elasticity
Disuse hampers the bl
periosteum
connective covering surrounding the bone
osteoclast
bone destroying cell
hydroxyapatite
mineralized calcium phosphate
red
type of bone marrow that produces blood cells
osteogenic
cell type that gives rise to bone producing cells
diaphysis
shaft of long bone
calcitonin
hormone released when calcium concentration is too high
parathyroid
hormone released when calcium concentration is too low
endochondral
ossification process of formation of bone that starts with cartilage (forms long bones)
compact
bone formed by osteons
stress
type of fracture caused by abnormal trauma to a bone
spongy
bone formed by trabeculae
collagen
protein that helps bones resist tension
bone marrow
soft tissue that occupies the medullary cavity of a long bone
osteocyte
cell found in bony cave
osteon
basic structural unit of compact bone
trabeculae
rods and plate of spongy bone
yellow
type of bone marrow that is mostly adipose
sesamoid
moslty tiny bones associated with tendons in areas where pressure develops, protect tendons from wear and tear.
sutural(wormian)
small bones of sutures
epiphysis
end of long bone
diaphysis
shaft of long bone
metaphysis
in adult bone, area where epiphysis meets diaphysis in adult bone
epiphyseal plate
area where epiphysis meets diaphysis in growing bone
articular cartilage
a layer of hyaline cartilage that covers joint surface
nutrient foramina
holes through which blood vessels enter the bone
perforating (volkmann) canals
carry blood vessels to central (haversian) canals in dense bone
periosteum
dense covering over surface of bone, two layers
fibrous layer
outer, contains blood and lymphatic vessels and nerves, involved in providing nourishment and removing wastes
osteogenic layer
inner, contains osteoblasts (bone forming cells)
endosteum
lines medullary cavity, contains osteoblasts and osteoclasts (bone dissolving cells)
medullary cavity (Canal)
contains yellow marrow in adults