Module 7 - Bone

Function of Bones

• Support

• Protection

• Movement

• Mineral homeostasis

• Hematopoiesis

• Storage of adipose tissue

Bone protects?

internal organs

provide leverage system for skeletal muscles, tendons, ligaments and joints

Bone

Bone provide leverage system for?

skeletal muscles, tendons, ligaments and joints

act as reserves of minerals important for the body like calcium or phosphorus

Bones

bones act as reserves of minerals important for the body like?

calcium or phosphorus

blood cell formation

Hematopoiesis

Storage of adipose tissue

Yellow marrow

Shape of Bones

• Long bones

• Short bones

• Flat bones

• Irregular bones

e.g., humerus, femur

Long bones

e.g., carpals, tarsals, patella

Short bones

e.g., parietal bone, scapula, sternum

Flat bones

e.g., vertebrae, hip bones

Irregular bones

Long bones example

• humerus,

• femur

Short bones example

• carpals,

• tarsals,

• patella

Flat bones example

• parietal bone,

• scapula,

• sternum

Irregular bones example

• vertebrae,

• hip bones

long shaft of bone

Diaphysis

ends of bone

Epiphysis

growth plate

Epiphyseal plate

between epiphysis and diaphysis

Metaphysis

Metaphysis is between?

Epiphysis and diaphysis

covers epiphysis

Articular cartilage

Articular cartilage covers?

epiphysis

bone covering (pain sensitive)

Periosteum

periosteum attaches to underlying bone

Sharpey’s fibers

hollow chamber in bone

Medullary cavity

red marrow produces?

blood cells

yellow marrow produces?

adipose

thin layer lining the medullary cavity

Endosteum

Dense outer layer

Compact Bone

honeycomb of trabeculae (needle-like or flat pieces) filled with bone marrow

Spongy Bone

Spongy Bone also known as?

Cancellous bone

What is the external layer of compact bone called?

Lamellar bone

groups of elongated tubules called?

lamella

Where is compact bone predominantly found?

Majority of all long bones

For protection and strength (wt. bearing

Compact Bone

blood vessels and nerves penetrate periosteum through horizontal openings called?

perforating (Volkmann’s) canal

Structural arrangement of compact bone

concentric ring structure

Bone is supplied with blood by:

• Periosteal arteries

• Epiphyseal veins

accompanied by nerves supply the periosteum and compact bone

Periosteal arteries

carry blood away from long bones

Epiphyseal veins

Periosteal arteries accompanied by ____ supply the periosteum and compact bone

nerves

Periosteal arteries accompanied by nerves supply the?

periosteum and compact bone

Epiphyseal veins carry ________ from long bones

blood away

Epiphyseal veins carry blood away from?

long bones

The periosteum is rich in sensory nerves sensitive to?

tearing or tension

accompany the blood vessels that supply bones

Nerves

The periosteum is rich in ___________, sensitive to tearing or tension

sensory nerves

What is the orientation of central (Haversian) canals?

Longitudinal

run longitudinally. Has blood vessels and nerves.

Central (Haversian) canals

surrounds the central (Haversian) canals

concentric lamella

It occupy lacunae which are between the lamella

Osteocytes

radiating from the lacunae are channels called?

canaliculi

finger like processes of osteocyte

canaliculi

Lacunae are connected to one another by?

canaliculi

Osteon contains:

1. central canal

2. surrounding lamellae

3. osteocytes

4. canaliculi

What is the internal layer of bone called?

Spongy bone (cancellous bone)

What type of tissue forms spongy bone?

Trabecular bone tissue

How are trabeculae arranged in spongy bone?

Haphazardly

Spongy bones are filled with?

red and yellow bone marrow

osteocytes get nutrients directly from?

circulating blood

short, flat and irregular bone is made up of mostly?

spongy bone

Cells are surrounded by matrix and its composed of?

25% water

25% protein

50% mineral salts

4 cell types make up osseous tissue

1. Osteoprogenitor cell

2. Osteoblasts

3. Osteocytes

4. Osteoclasts

Osteoprogenitor cells are derived from?

mesenchyme

Osteoprogenitor cells are unspecialized ________?

unspecialized stem cells

Osteoprogenitor cells undergoes _______ and develop into osteoblast

mitosis

Osteoprogenitor cells develops into?

osteoblasts

Osteoprogenitor cells are found in?

inner surface of periosteum and endosteum

found on inner surface of periosteum and endosteum.

Osteoprogenitor cells

bone forming cells

Osteoblasts

found on surface of bone (arrow)

Osteoblasts

Osteoblasts are found on?

surface of bone

Osteoblasts has no ability to?

mitotically divide

Osteoblasts secretes?

collagen

collagen secretors

Osteoblast

mature bone cells

Osteocytes

derived form osteoblasts

Osteocytes

Osteocytes are derived from?

osteoblasts

Osteocytes does not secrete?

matrix material

cellular duties include exchange of nutrients and waste with blood.

Osteocytes

Osteocytes cellular duties include exchange of?

nutrients and waste with blood

bone resorbing cells

Osteoclasts

Osteoclasts are found in?

the bone surface

For growth, maintenance and bone repair

Osteoclasts

Abundant inorganic mineral salts:

1. Tricalcium phosphate in crystalline form

2. Calcium Carbonate: CaCO3

3. Magnesium Hydroxide: Mg(OH)2

4. Fluoride and Sulfate

Tricalcium phosphate in crystalline form called?

hydroxyapatite

cartilage producing cells

Chondrocytes

small cavities where the chondrocytes are encased.

Lacunae

jellylike ground substance

Extracellular matrix

Layer of dense irregular connective tissue that surrounds the cartilage.

Perichondrium

Skeletal cartilage has no?

No blood vessels or nerves

The process of bone formation is called

ossification

Bone formation occurs in four situations:

1) Formation of bone in an embryo

2) Growth of bones until adulthood

3) Remodeling of bone

4) Repair of fractures

cartilage formation and ossification occurs during the?

sixth week of embryonic development

This occurs during the 6th wk of embryonic development

cartilage formation and ossification occurs

Flat bones of the skull and mandible are formed in this way

Intramembranous ossification

formed through intramembranous ossification

Flat bones of the skull and mandible