1. Support-bones are the body's infrastructure

2. Storage of minerals-98% of body's calcium is in bones

3. Blood cell production-bone marrow produces new blood cells

4. Protection-delicate organs surrounded by bone

5. Leverage-muscles pull on bone to produce movement

Classification (types) of bones

Examples

1. Long-humerous, radius, tibia, femur

2. Short-cube shaped-carpal and tarsal

3. Flat-sternum, ribs, scapula

4. Irregular-odd shapes-bones of the face and vertebrae

5. Suture-small bones filling in the space between skull bones

6. Sesamoid-surrounded by other types of tissue-patella

1.Supporting connective tissues (cells, calcified matrix)

2. Periosteum-Outer covering

3. Endosteum-inner lining

Specialized cells (osteoblasts/osteocytes)

Produce:

A) Collagen fibers

B) Ground substance:

calcium phosphate

some calcium carbonate

Organic components of the matrix

-produced by osteoblasts and osteocytes

1. Mesenchyme

2. Osteoprogenitor cells

3. Osteoblasts

4. Osteocytes

5. Osteoclasts

Beginnning of ALL connective tissue (Embryonic Tissue)

-semi-fluid ground substance with delicate reticular fibers

*Becomes osteoprogenitor cells*

Derived from mesenchymal cells

-found in inner and outer surfaces of a bone

-Divides by mitosis-->differentiate to form new osteoblasts

Immature, active cells that build bone

*Derived from osteoprogenitor cells*

-CANNOT divide by mitosis

-Found on bone surfaces

-Performs osteogenesis

Mature cells

-maintain bone tissue

*Derived from osteoblasts*

-CANNOT divide by mitosis

-Giant multinucleated cells

-Perform osteolysis

-Used in development, growth, and repair

(remodeling)

Bone reabsorption

Performed by osteoclasts

1. Isolates and Protects the bone from surrounding tissues

2. Provides a route and a place for attachment for circulatory and nervous supply

3. Actively participates in bone growth and repair

1. Lines spicules/trabeculae of spongy bone (found in ends of long bones)

2. Lines medullary cavity (center bone cavity of shaft)

3. Lines central canals of osteons

1. Compact bone

2. Spongy bone

Dense and solid

-Osteon is the funtional unit

(many osteons form compact bone)

open framework

-Spicule is the functional unit of spongy bone

(Many Spicules together (trabecula) make spongy bone) 

bone replacing existing tissue

-structural change into bone

growth in diameter

-occurs in all types of bones

-increase in width at the periosteum

growth in length

-occurs mainly in long bones

-increase in length at the epiphyseal plate

-Bone builds off of epiphyseal plate (hyaline cartilage)

-When building ceases, the plate turns to bone and becomes the epiphyseal line

1. Intramembranous ossification

2. Endochondral ossification

Intramembranous ossification bone development

-type of growth performed

-occurs mainly in dermal bones (bones you can feel)-flat bones

-bone develops between 2 sheets of embryonic membranes (CT)

-perform appositional growth

Endochondral ossification bone development

-type of growth performed

-occurs mainly in long bones

-bones develop from hyaline cartilage model

-growth is appositional OR interstitial

1. Mesenchymal cells

2. Mesenchymal cells differentiate into osteoblasts

3. Osteoblasts secrete matrix

4. Matrix formed with osteocytes in lacunae

5. Spicules form

6. Spicules connect (trabeculae) to form spongy bone

7. Endosteum forms around spicules

8. Spongy bone differentiates to form compact bone

STEP 1

1. Mesencymal cells differentiate into chondroblasts

2. Chondroblasts secrete matrix

3. Chondroblasts surrounded by matrix become chondrocytes in lacunae

4. Cartilage model formed

STEP 2

1. Step 1

2. Blood vessels of perichondrium bring osteoblasts to form periosteum collar

3. Hypertrophy (build up of chondrocytes) and death of cartilage cells at primary ossification center

4. Bone replaces cartilage (osteoblasts from spicules)

5. Formation of secondary ossification center in epiphysis

6. Bone replaces cartilage at secondary ossification center

7. Hyaline cartilage remains at epiphyseal plate until growth completed and on articular surfaces forever--becomes epiphyseal line

Ions

-Calcium, phosphate, magnesium, citrate, carbonate, sodium

Vitamins

-Vitamins A and C

-Vitamin D derivatives

1. Parathyroid hormone

2. Calcitonin

3. Growth hormone and thyroxine

4. Sex hormones

Factor that regulates bone growth

-(PTH)

-acts to increase availability of calcium ions in the blood

-Increased osteoclast activity is the direct result of PTH levels

Factor that regulates bone growth

-antagonist of PTH

-decreases availability of calcium

Factor that regulates bone growth

-increases osteoblast activity, which leads to bone growth

Fator that regulates bone growth

-increase bone growth dramatically during puberty

1. Bleed-fracture hematoma develops

2. Callus-external callus of cartilage and bone stabilizes the outer edges

3. Remodel via osteoclasts-fragments of broken bone are removed and replaced, cartilage is replaced by bone

4. Repair-External callus will slowly diminish

1. Calcium and other mineral loss (demineralization)--leads to osteoperosis

2. Decreased rate of protein synthesis

-decrease in collagen (bone strength)

-decrease in growth hormone

-bone becomes brittle and susceptible to fracture

Osteoperosis

-those at risk

-prevention

Decreased bone mass resulting in porous bones

-Risk: 1-white, thin menopausal, smoking, drinking female with family history

2-Athletes who are not menstruating due to decreased body fat and estrogen levels

3-People with low calcium intake

Prevention

-adequate diet

-weight-bearing exercise

-estrogen replacement for menopausal women

1. bones from the skul, vertebral colmn, and thorax

2. special sense organs for taste, smell, hearing, balance, and vision

3. Serves as attachment sites for muscles

Fontanels

1. what are they?

2. What is their purpose?

1. Membrane filled regions between cranial bones of infant skull (soft spots)

2. Allow skull to be flexible for birth and for fast growth of the brain

26

(24 vertebra, 1 sacrum, 1 coccyx)

1. Encloses and protects the spinal cord

2. Supports the skull

3. Supports the weight of the head, neck and trunk

4. Transfers weight to the lower limbs

5. Helps maintain upright position

Name of the C1 vertebrae

Articulation of the C1 vertebrae

Atlas

Shake head up and down to nod "yes"

Name of the C2 vertebrae

Articulation of the C2 vertebrae

Axis

Shake head side to side to nod "no"

-Protects the heart, lungs, thymus, and other stuctures in cavity

-Serves as attachment sites for muscles involved in respiration, positioning the vertebral column, and movements of the pectoral girdle and upper limb

1. Snoring

2. Sinusitis

Landmark

Bony orbital

1. Type of of movement (function)

2. Type of connective tissue (structure)

1. Synarthrosis

2. Amphiarthrosis

3. Diarthrosis/synovial

no movement at the joint

IE-between skull bones

slight motion at the joint

IE Symphysis pubis

freely moveable with a joint cavity

IE elbow, femur, humerus

1. Fibrous joints

2. Cartilaginous joints

3. Synovial joints

1. Sutures

2. Syndesmoses

3. Gomphosis

Sutures

-general structure

-function

-example

holds bone together via suture bone

-structure=fibrous joint

-function=synarthrosis

-sutures of skull

Syndesmoses

-general structure

-function

-example

long connective tissue bands

-structure=Fibrous joint

-function=amphiarthrosis

-example-interosseous membrane between bones in distal appendages

Gomphosis

-general structure

-function

-example

short connective tissue bands

-Structure=fibrous joints

-function=synarthrosis

(ONLY EXAMPLE IS ligaments attached to teeth)

1. Synchondroses

2. Symphyses

Synchondroses

-general structure

-function

-examples

hyaline cartilage

-cartilaginous joint

-synarthrosis: short hyaline cartilage

 and amphiarthrosis: longer hyaline cartilage

-rib to sternum, epiphyseal plate in growing bone

Symphyses

-structure

-function

-examples

Fibrocartilage holds bones together

-structure=cartilaginous joint

-function=amphiarthrosis

-example-symphysis pubis, intervertebral discs

1. Shock absorber

2. Nourishes chondrocytes by entering and exiting the articular cartilages due to the forces acting on the joint

3. Lubricates the surfaces of the articular cartilages on the ends of the bones

Terrible triad

-action that causes it

-ligaments torn

-what is felt by patient

-How to repair

-Medial collateral ligament and medial meniscus injury

-Lateral blow to the knee

-rupture of MCL and tear of medial meniscus, can include the ACL

-Patient hears a pop and feels a tear

-MCL heals with time, T-Tri requires surgury