Journal #5: How many bones are in the human body? Do you think there are more

in your axial or appendicular skeleton? • Fun Fact:

The only bone in the human body not connected to another is the hyoid, a V-shaped bone located at the base of the tongue.

• Objective: – Describe the function

of the skeletal system– Classify bones

according to their shapes and markings

– Compare the structure and function of compact and spongy bone

Part I: Gross Anatomy and Histology pgs. 180-188

Ch. 6 Osseous Tissue &Bone Structure

Function of the Skeletal System

• Support: Framework for the attachment of tissues and organs

• Storage of Minerals & Lipids: Calcium and Lipids in Marrow

• Blood Cell Production: Red marrow produces both red and white blood cells

• Protection: Surrounds delicate organs

• Leverage: range of motion

Gross Anatomy

• Types of Bones (206 bones total)– Long: long and slender; arm, legs, fingers, toes– Flat: thin and parallel; sternum, ribs, scapula,

top of skull– Sutural: flat and irregularly shaped puzzle

pieces of the skull– Irregular: complex shapes; vertebrae– Short: small & boxy; wrists & ankles– Sesamoid: small, flat, shapes like a seed;

patella

Bone Markings

• Surface features which help to describe a bone– Elevations & projections: process or ramus– Processes formed where tendons or ligaments attach:

trochanter, tuberosity, tubercle, crest, line, spine– Processes formed for articulation with adjacent

bones: head, neck, condyle, trochlea, facet– Depressions: fossa or sulcus– Openings: foramen, canal, fissure, sinus or

antrum

Bone Structure

• Long bones– Diaphysis: long tubular shaft (compact bone

with a marrow cavity in the center)– Epiphysis: expanded area at end (mainly

spongy bone with a thin cortex of compact bone)

– Metaphysis: area between epi and dia

• Flat bones– Cortex of compact bone with Diploe of spongy

bone in the center

Structure of a Long Bone

Use the Femur Bone to label the following:pg. 182

• Trochanter: large rough projection where tendons or ligaments attach

• Head: Expanded articular end of an epiphysis (separated from the shaft by a neck)

• Neck: Narrow connection between epiphysis and diaphysis

• Tubercle: small rounded projection when tendons or ligaments attach

• Facet: A small flat articular surface• Condyle: smooth rounded articular process (bump)• Epiphysis/ Diaphysis/ Metaphysis

On Humerus Label:• Tubercle• Head• Sulcus• Neck• Tuberosity• Fossa• Trochlea• Condyle• & Epiphysis, Diaphysis, Metaphysis

Bone Histology (Tissues) (bone notes part 2)

• Supporting connective tissue• Matrix made of calcium salt deposits with

collagen fibers• Cells:

– Osteocytes: mature bone cells that maintain the bone matrix and repair damaged bone

– Osteoblasts: immature bone cells that secrete matrix components

– Osteoprogenitor cells: stem cells which produce osteoblasts

– Osteoclasts: cells that remove and recycle bone in a process called osteolysis

Structure of Compact Bone

• Each unit is an osteon (Haversion System)– Osteocytes arranged in concentric layers around a

central canal (Haversion Canal)• Each canal contains one or more blood vessels• Run parallel to surface of bone• Perforating canals run perpendicular

– Concentric lamella add strength and resiliency– Interstitial lamellae between osteons with space

between called canaliculi – Cirumferential lamellae found at outer and inner

surface of bone (covered by either periosteum or endosteum)

Structure of Spongy Bone

• Not arranged in osteons• Matrix forms branching trabeculae• No capillaries or venules; diffusion through

canaliculi• Located where bone is not heavily

stressed (reduces the weight of the skeleton)

• Protects marrow (red- blood cell formation, yellow adipose storage)

Periosteum & Endosteum

• Periosteum– Isolates bone from

surrounding tissue– Circulation & nerve supply– Bone growth & repair– Collagen fibers are

continuous with joint capsules & attached tendons and ligaments

• Endosteum– Lines the marrow cavity– Layer of osteoprogenitor

cells– Growth, repair, remodeling

Journal #5: Read “Types of Fractures” on

pg. 200. • Which type of fracture is

usually the simplest to treat?

• Who is most likely to have a greenstick fracture? Why?

• When is a Colles’ fracture likely to occur?

• Objective 4: – Discuss how bone grows,

heals, and remodels itself.– Know the conditions that

affect bone growth.